Loredana Macaluso
email: macalusoloredana@gmail.com

Letizia Jérémy Martin

Del Favero

Massimo Delfino
email: massimo.delfino@unito.it

Jeremy E Martin
email: jeremy.martin@ens-lyon.fr

Del Letizia
email: letizia.delfavero@unipd.it

Favero

Al.-Oligocene Macaluso

From Crocodilians

Monteviale

Jeremy E Martin

Revision of the crocodilians from the Oligocene of Monteviale, Italy, and the diversity of European eusuchians across the Eocene-Oligocene boundary

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

It has been suggested that the composition of the freshwater crocodilian fauna of Europe may have been affected by climatic deterioration around the Eocene-Oligocene boundary (33.9 million years ago; [START_REF] Markwick | Fossil crocodilians as indicators of Late Cretaceous and Cenozoic climates: implications for using palaeontological data in reconstructing palaeoclimate[END_REF][START_REF] Martin | A new species of Diplocynodon (Crocodylia, Alligatoroidea) from the Late Eocene of the Massif Central, France, and the evolution of the genus in the climatic context of the Late Palaeogene[END_REF]. Indeed, a marked decline in diversity is observed between the greenhouse Eocene assemblages, when the European crocodilian fauna is comprised of at least four taxa per locality (with a maximum of seven taxa for Messel; [START_REF] Berg | Die Krokodile, insbesondere Asiatosuchus und aff. Sebecus?, aus dem Eozän von Messel bei Darmstadt/Hessen[END_REF][START_REF] Morlo | An annotated taxonomic list of the Middle Eocene (MP11) vertebrata of Messel[END_REF][START_REF] Hastings | Terrestrial Conservation Lagerstätten: Windows into the Evolution of Life on Land[END_REF], and the subsequent cooler Oligocene assemblages, wherein each locality hosts the single genus Diplocynodon.

Diplocynodon is therefore thought to have survived dramatic climatic change (see [START_REF] Martin | A new species of Diplocynodon (Crocodylia, Alligatoroidea) from the Late Eocene of the Massif Central, France, and the evolution of the genus in the climatic context of the Late Palaeogene[END_REF], for a review).

Italy possesses a rich Cenozoic record of crocodilians [START_REF] Kotsakis | Italian Cenozoic crocodilians: taxa, timing and biogeographic implications[END_REF]Delfino et al., 2007;[START_REF] Piras | Phylogenetic position of the crocodylian Megadontosuchus arduini (de Zigno, 1880) and tomistomine palaeobiogeography[END_REF][START_REF] Abbazzi | New data on the vertebrate assemblage of Fiume Santo (North-West Sardinia Italy) and overview on the Late Miocene Tusco-Sardinian palaeobioprovince[END_REF][START_REF] Delfino | African crocodylians in the Late Neogene of Europe. A revision of Crocodylus bambolii Ristori, 1890[END_REF][START_REF] Delfino | Fossil crocodylid remains from Scontrone (Tortonian, Southern Italy) and the late Neogene Mediterranean biogeography of crocodylians[END_REF][START_REF] Colombero | Late Messinian mollusks and vertebrates from Moncucco Torinese, north-western Italy. Paleoecological and paleoclimatological implications[END_REF]. Among the most famous localities, the lignite deposits from the Eocene of Monte Bolca and the Oligocene of Monteviale have yielded many, often articulated, specimens. Crocodilians from Monte Bolca were attributed to two different taxa by [START_REF] Sacco | I coccodrilli del Monte Bolca[END_REF]: Crocodilus vicetinus Lioy, 1865, and Crocodilus bolcensis [START_REF] Sacco | I coccodrilli del Monte Bolca[END_REF]. The taxonomic affinity of this material is unclear and awaits revision, but there are currently at least three taxa identified: Asiatosuchus, Allognatosuchus and Boverisuchus [START_REF] Kotsakis | Italian Cenozoic crocodilians: taxa, timing and biogeographic implications[END_REF]. The reported presence of a species of Diplocynodon at Monte Bolca [START_REF] Papazzoni | The Bolca Fossil-Lagerstatten: A window into the Eocene World[END_REF] is erroneous, as the only specimen (MGP-PD 27403) of this genus labelled as coming from this locality is most likely from Monteviale (see below; [START_REF] Favero | Un esemplare di Diplocynodon Pomel, 1847 (Crocodylia, Leidyosuchidae) conservato nel museo geopaleontologico dell[END_REF][START_REF] Kotsakis | Italian Cenozoic crocodilians: taxa, timing and biogeographic implications[END_REF]. At the beginning of the 20 th century, two species from the Oligocene locality of Monteviale were erected: Crocodilus monsvialensis [START_REF] Fabiani | La serie stratigrafica del Monte Bolca e dei suoi dintorni[END_REF], and Crocodilus dalpiazi Fabiani, 1915[START_REF] Fabiani | La serie stratigrafica del Monte Bolca e dei suoi dintorni[END_REF] remarked that C. monsvialensis had close affinities with C. vicetinus from Monte Bolca, but differed substantially enough to be designated as a new species. [START_REF] Fabiani | La serie stratigrafica del Monte Bolca e dei suoi dintorni[END_REF] briefly listed differences in shape and size of the temporal fenestrae, position of the frontoparietal suture, proportions of the frontal and prefrontal elements, and shape of the nares. Later, Berg (1966:40) proposed that Diplocynodon Pomel, 1847, was possibly present at Monte Bolca and Monteviale. He also proposed that some remains from Monteviale shared the same characters with what he referred to as "Crocodilus" vicetinus from Monte Bolca, probably belonging to the same taxon.

The latest comprehensive revisions of the crocodilian assemblage from Monteviale date from the early 1990s. Two taxa were recognized: Diplocynodon dalpiazi [START_REF] Fabiani | Il Paleogene del Veneto[END_REF] by [START_REF] Franco | Resti di coccodrilli Diplocynodonti (Diplocynodon dalpiazi) dall'Oligocene di Monteviale (Vicenza) nel Museo Paleontologico Universitario di Padova[END_REF] and Asiatosuchus monsvialensis [START_REF] Fabiani | La serie stratigrafica del Monte Bolca e dei suoi dintorni[END_REF] by [START_REF] Franco | A small crocodilian species from the Oligocene of Monteviale in Vicentinian, Asiatosuchus monsvialensis (Fabiani, 1914)[END_REF]. However, both [START_REF] Rauhe | News about fossil crocodiles from the Middle Eocene of Messel and Geiseltal, Germany[END_REF] and [START_REF] Kotsakis | Italian Cenozoic crocodilians: taxa, timing and biogeographic implications[END_REF] expressed doubts about the presence of two species at Monteviale, suggesting that all these crocodilians belong to a single species of Diplocynodon instead. This view was also supported by [START_REF] Brinkmann | Diplocynodon ratelii Pomel, 1847 (Crocodylia, Leidyosuchidae) aus dem unter-Oligozän von Céreste (Südfrankreich)[END_REF] in their description of a new specimen from the late Early Oligocene of Céreste, southern France, pertaining to the species Diplocynodon ratelii [START_REF] Pomel | Note sur des animaux fossiles découverts dans le département de l'Allier[END_REF][START_REF] Favero | Un esemplare di Diplocynodon Pomel, 1847 (Crocodylia, Leidyosuchidae) conservato nel museo geopaleontologico dell[END_REF] provided a detailed description of the problematic specimen then thought to be from Monte Bolca (MGP-PD 27403), which she referred to Diplocynodon cf. ratelii. Nannofossils in the matrix surrounding that specimen revealed that it was geologically younger, and therefore from Monteviale. [START_REF] Delfino | A reassessment of the morphology and taxonomic status of 'Crocodylus' depressifrons Blainville, 1855 (Crocodylia, Crocodyloidea) based on the Early Eocene remains from Belgium[END_REF] mentioned that the youngest representatives of Asiatosuchus could be those from Monteviale if "the referral of 'Crocodilus' monsvialensis [START_REF] Fabiani | La serie stratigrafica del Monte Bolca e dei suoi dintorni[END_REF] to crocodyloids by [START_REF] Franco | A small crocodilian species from the Oligocene of Monteviale in Vicentinian, Asiatosuchus monsvialensis (Fabiani, 1914)[END_REF] is valid. Finally, [START_REF] Pandolfi | Reassessing the earliest Oligocene vertebrate assemblage of Monteviale (Vicenza, Italy)[END_REF] provided a brief description of the crocodilians from Monteviale, attributing them to a single taxon, Diplocynodon cf. ratelii.

As shown above, the history of the knowledge of the Monteviale crocodilians is rather convoluted and the precise composition of the assemblage is somewhat still unclear. Although the systematic affinities of these crocodilians have been discussed by various authors, a detailed account of the osteology of the Monteviale crocodilians has yet to be carried out. The works of [START_REF] Franco | Resti di coccodrilli Diplocynodonti (Diplocynodon dalpiazi) dall'Oligocene di Monteviale (Vicenza) nel Museo Paleontologico Universitario di Padova[END_REF] and [START_REF] Franco | A small crocodilian species from the Oligocene of Monteviale in Vicentinian, Asiatosuchus monsvialensis (Fabiani, 1914)[END_REF] consist of an exhaustive catalogue of the specimens, but do not include full osteological descriptions based on diagnostic characters. In this context, the presence of Asiatosuchus and Diplocynodon in the Oligocene of Monteviale remains to be verified.

We herein provide a detailed osteological description of the Monteviale specimens, housed in the collection of the "Museo Geologia e Paleontologia" of Padua, Italy, and of two previously unreported skeletons housed in the collections of the Musée de La Rochelle, France, and the Naturhistorisches Museum in Basel, Switzerland, that may come from the same locality. This description offers a basis to evaluate the presence of two sympatric taxa in the crocodilian assemblage of Monteviale. We intend to verify if the idea that the diversity of the Oligocene crocodilian assemblage of Italy is really an exception if compared to the European standard, or if the occurrence of Asiatosuchus should be discarded, thus confirming the hypothesis of a major reduction in the diversity of crocodilian assemblages around the Eocene-Oligocene boundary.

Ambigous Provenance

The Monteviale origin of the specimens housed in Padua is well confirmed in the catalogues of the museum (except for MGP-PD 27403, most likely from Monteviale labelled as coming from Monte Bolca; see [START_REF] Favero | Un esemplare di Diplocynodon Pomel, 1847 (Crocodylia, Leidyosuchidae) conservato nel museo geopaleontologico dell[END_REF][START_REF] Kotsakis | Italian Cenozoic crocodilians: taxa, timing and biogeographic implications[END_REF]. The provenance of the two previously unreported crocodilian skeletons is discussed below. They were donated to the collections of Basel and La Rochelle, where they are currently kept, at the beginning of the 20 th century.

The Basel specimen does not bear any label and thus, the knowledge of its provenance is uncertain. The catalogue of entries at the Naturhistorisches Museum in Basel records in 1904 "Bc. 6. Crocodilus spec. Vorderer Theil eines Skeletes von oben sichtbar, mit gut erhaltenem Schädel" from the Lower Oligocene of Monte Bolca, this locality being also denoted as Monteviale (L. Costeur, pers. comm. to Jeremy Martin 2007). The crocodilian skeleton of La Rochelle was purchased for 900 Francs from "Les Fils d'Emile Deyrolle", a company based in Paris and providing natural history specimens for sale. The acquisition letter mentions a skeleton of Crocodilus vicetinus from Monte Bolca and is dated to the 10 th of December 1931. The same specimen appears to be advertised in a natural history catalogue "Le Naturaliste" also published by "Les Fils d'Emile Deyrolle" and dated from 1908 (R. Vullo, pers. comm. to Jeremy Martin 2011).

The provenance and age of both specimens is therefore equivocal. The sites of Monte Bolca (middle Eocene) and Monteviale (early Oligocene) are located in the same Italian area, and Monte Bolca was, and still is, much more popular than Monteviale. Confusion about the provenance of fossils from these two localities has always been an issue, and [START_REF] Berg | Die Krokodile, insbesondere Asiatosuchus und aff. Sebecus?, aus dem Eozän von Messel bei Darmstadt/Hessen[END_REF] did not provide any extensive comment on this, just stating that the provenance of Diplocynodon from Monte Bolca or Monteviale was unclear. [START_REF] Kotsakis | Italian Cenozoic crocodilians: taxa, timing and biogeographic implications[END_REF] and [START_REF] Pandolfi | Reassessing the earliest Oligocene vertebrate assemblage of Monteviale (Vicenza, Italy)[END_REF] reported that some mammals and crocodilians were likely to have been discovered at Monteviale and then referred by mistake to Monte Bolca. The catalogue of entries in Basel is consistent with such a possibility as the initial name of the locality (Monte Bolca) is crossed and replaced with "Monteviale". Moreover, the collection is ordered stratigraphically and the crocodilian NMB-Bc.6 and associated mammal material from Monteviale are listed and placed in the upper Rupelian section (and thus among the Oligocene materials, not among the Eocene ones).

The designation of 'Monte Bolca' as a locality incorporates various fossiliferous sites of three different depositional environments: Monte Postale and Pesciara di Bolca consisting of micritic limestone deposited in a marine environment [START_REF] Papazzoni | The Bolca Fossil-Lagerstatten: A window into the Eocene World[END_REF]; Spilecco consisting of marly limestones deposited in a shallow water environment [START_REF] Papazzoni | The Bolca Fossil-Lagerstatten: A window into the Eocene World[END_REF]; Purga di Bolca and Vegroni consisting of lignite seams reminiscent of a freshwater depositional environment [START_REF] Barbieri | Contributo alla conoscenza geologica della regione di Bolca (Monti Lessini)[END_REF][START_REF] Favero | Un esemplare di Diplocynodon Pomel, 1847 (Crocodylia, Leidyosuchidae) conservato nel museo geopaleontologico dell[END_REF]. Only the Pesciara di Bolca benefited from a recent detailed stratigraphic study and a middle Eocene age has been assigned to it [START_REF] Papazzoni | Facies analysis, palaeoenvironmental reconstruction, and biostratigraphy of the "Pescaria di Bolca" (Verona, northern Italy): an early Eocene Fossil-Lagerstätte[END_REF]). An early-middle Eocene age has been proposed for Purga di Bolca [START_REF] Papazzoni | The Bolca Fossil-Lagerstatten: A window into the Eocene World[END_REF]. That the museums of Basel and La Rochelle refer their specimens to Monte Bolca or to Crocodilus vicetinus (one of the species described on the basis of material from Monte Bolca) might be due to confusion with Monteviale, or these fossils could genuinely come from lignite sites of Purga di Bolca.

The two crocodilian skeletons from Basel and La Rochelle likely come from Monteviale on the basis of a morphological comparison and the similar encasing matrix of the material with the specimens housed in Padua, which certainly come from Monteviale.

However, the assigning of provenance based on these factors is tentative. For this reason, a geochemical analysis comparing the matrix surrounding specimens of known and unknown provenance is presented below.

Institutional

MATERIAL AND METHODS

Material

The Monteviale material is subject to degradation connected to pyrite oxidation (see [START_REF] Larkin | Pyrite Decay: cause and effect, prevention and cure[END_REF]. To deal with this problem, during the past century the Padua material has been treated with several varnishes, which covered and obliterated most of the sutures among the bones, making the material very difficult to examine. The specimen housed in the Naturhistorisches Museum in Basel is the best preserved, as it has been mechanically extracted from the slab and treated with ammonium gas and paraffin to preserve it from pyrite oxidation. The skeleton housed in La Rochelle remains within its original lignite matrix, unprepared in 3D. Most of the material is figured in Appendix 1.

Provenance Analysis

Lignites are sedimentary rocks formed from the aggregation of terrestrial plant material and thus they have a variable content of carbon. The plants that make up lignites grow on soil whose minerals originate from the weathering of substrates. Because geological substrates of different natures have their own radiogenic strontium isotope composition (expressed as 87 Sr/ 86 Sr), so do soils that grow on it as well as associated plant remains and organisms that will feed on these plants, thus reflecting a local strontium isotope value [START_REF] Graustein | 87 Sr/ 86 Sr ratios measure the sources and flow of strontium in terrestrial ecosystems[END_REF][START_REF] Blum | Changes in Sr/Ca, Ba/Ca and 87 Sr/ 86 Sr ratios between trophic levels in two forest ecosystems in the northeastern U.S.A[END_REF]. The lignites of Purga di Bolca are several million years older (middle Eocene) than the lignites of Monteviale (early Oligocene) [START_REF] Papazzoni | Facies analysis, palaeoenvironmental reconstruction, and biostratigraphy of the "Pescaria di Bolca" (Verona, northern Italy): an early Eocene Fossil-Lagerstätte[END_REF]Papazoni et al., 2014;[START_REF] Pandolfi | Reassessing the earliest Oligocene vertebrate assemblage of Monteviale (Vicenza, Italy)[END_REF] and should possess different geochemical compositions. Therefore, we predict that the radiogenic strontium isotope ratio (expressed as 87 Sr/ 86 Sr) of samples from Purga di Bolca will differ from samples from Monteviale. To test this hypothesis, 87 Sr/ 86 Sr ratios were measured on two lignite samples from Purga di Bolca as well as on two specimens from Monteviale (MGP26855 and MGP26836). In addition, three samples of uncertain provenance including the two specimens presented above (La Rochelle and Basel), as well as one specimen housed in NHM-UK and labelled as coming from from Purga di Bolca, were analyzed. 87 Sr/ 86 Sr ratios were measured on a Nu instrument-500 multicollector-ICPMS with a Phoenix laser ablation inlet (Photon-Machines) at the Laboratoire de Géologie de Lyon. We are not aware of reference material for 87 Sr/ 86 Sr ratio in lignite, so we used a homogenous standard of known strontium isotopic composition (SRM-1400, Bone Ash) as a bracketing reference for correcting instrumental biases during measurements. The standard SRM-1400 contains 250 p.p.m. of strontium and produces about 3 volts on mass 88 Sr on the multicollector ICPMS. The standard SRM 1400 yields an average 87 Sr/ 86 Sr raw value of 0.71371 ± 0.00526 (2 s.d.), which is comparable to the TIMS value of 0.71310 ± 0.00002 (2 s.d.) [START_REF] Schweissing | Tracing migration events in man and cattle by stable strontium isotope analysis of appositionally grown mineralized tissue[END_REF]. Each sample was ablated three times with a spot diameter of 100 µm.

Phylogenetic Analysis

The Monteviale specimens were scored as a single taxon and included in the data matrix of [START_REF] Martin | Late Palaeocene eusuchian remains from Mont de Berru, France, and the origin of the alligatoroid Diplocynodon[END_REF] for eusuchians, which contained a total of 97 taxa, 98 including the Monteviale crocodilian, and 179 characters (Appendix 2). The matrix was assembled using Mesquite [START_REF] Maddison | Mesquite: a modular system for evolutionary analysis[END_REF]. The characters are from [START_REF] Brochu | A new species of Borealosuchus (Crocodyliformes, Eusuchia) from the Late Cretaceousearly Paleogene of New Jersey[END_REF] Appendix 3), which are the same used by [START_REF] Martin | Late Palaeocene eusuchian remains from Mont de Berru, France, and the origin of the alligatoroid Diplocynodon[END_REF]. All of the most informative species of Diplocynodon part of this data matrix: Diplocynodon darwini, D. deponiae, D. hantoniensis, D. ratelii, D. muelleri, D. tormis, and D. remensis. Another analysis was conducted that also included two less complete species of Diplocynodon, D. elavericus and D. ungeri, which were also included in some previous analyses [START_REF] Martin | A new species of Diplocynodon (Crocodylia, Alligatoroidea) from the Late Eocene of the Massif Central, France, and the evolution of the genus in the climatic context of the Late Palaeogene[END_REF][START_REF] Martin | Taxonomic clarification of Diplocynodon Pomel, 1847 (Crocodilia) from the Miocene of Styria, Austria[END_REF][START_REF] Martin | Late Palaeocene eusuchian remains from Mont de Berru, France, and the origin of the alligatoroid Diplocynodon[END_REF]. Replicates of 1000 random addition sequences were performed under TNT [START_REF] Goloboff | Program and documentation available from the authors[END_REF], using the traditional search with the TBR algorithm to search for shortest trees. Bernissartia fagesii was defined as the outgroup taxon as in [START_REF] Martin | Late Palaeocene eusuchian remains from Mont de Berru, France, and the origin of the alligatoroid Diplocynodon[END_REF].

SYSTEMATIC PALEONTOLOGY

Order CROCODILIA Gmelin, 1789 Suborder EUSUCHIA Huxley, 1875 Superfamily ALLIGATOROIDEA Gray, 1844 Family DIPLOCYNODONTIDAE Hua, 2004 Genus DIPLOCYNODON Pomel, 1847 DIPLOCYNODON CF. D. MUELLERI [START_REF] Kälin | Hispanochampsa mülleri nov. gen. nov. spec., ein neuer Crocodilide aus dem unteren Oligocaen von Tárrega (Catalonien)[END_REF] (Figs. 1234567)

Crocodilus monsvialensis Fabiani, 1914:233. Crocodilus dalpiazi [START_REF] Fabiani | Il Paleogene del Veneto[END_REF]:306. "Crocodilus" vicetinus Lioy, 1865: Berg, 1966:58. Diplocynodon dalpiazi [START_REF] Fabiani | Il Paleogene del Veneto[END_REF]): Franco et al., 1992:130, figs 2-17, pl. 1-3. Asiatosuchus monsvialensis [START_REF] Fabiani | La serie stratigrafica del Monte Bolca e dei suoi dintorni[END_REF]: Franco and Piccoli, 1993:101, figs. 3-12, pl. 1-

3.

Asiatosuchus monsvialensis [START_REF] Fabiani | La serie stratigrafica del Monte Bolca e dei suoi dintorni[END_REF]: Roccaforte et al., 1994:380. Diplocynodon dalpiazi [START_REF] Fabiani | Il Paleogene del Veneto[END_REF]: Roccaforte et al., 1994:380. Diplocynodon [START_REF] Pomel | Note sur des animaux fossiles découverts dans le département de l'Allier[END_REF]: Rauhe and Rossmann, 1994: 84. Diplocynodon ratelii [START_REF] Pomel | Note sur des animaux fossiles découverts dans le département de l'Allier[END_REF]: Brinkman and Rauhe, 1998:307-308. Diplocynodon cf. ratelii Pomel, 1847: Del Favero, 1999:110. Diplocynodon cf. ratelii [START_REF] Pomel | Note sur des animaux fossiles découverts dans le département de l'Allier[END_REF]: Pandolfi et al., 2016:13-14, figs. 9-10. MGP-PD 27403 is the previously mentioned slab labelled "Monte Bolca," but as shown below via provenance analysis, it most likely comes from Monteviale. It contains an almost complete specimen which was described by Del [START_REF] Favero | Un esemplare di Diplocynodon Pomel, 1847 (Crocodylia, Leidyosuchidae) conservato nel museo geopaleontologico dell[END_REF]. NMB-Bc.6 is the anterior half of a skeleton with a complete skull showing its dorsal and ventral surfaces (Fig. 1); this slab also contains two areas (indicated with A and B in Fig. 1), with bones belonging to one or two smaller individuals.

Referred material-See

MLR-no number, slab with a skeleton bearing a skull visible in dorsal view and disarticulated and fragmented portion of the postcranial skeleton.

NHM-UK 2789 is slab particularly altered by pyrite oxidation containing the thoracic portion of a small individual and part of its limbs.

Occurrence-Early Oligocene (late Rupelian) of Monteviale, Vicenza, north-eastern Italy [START_REF] Pandolfi | Reassessing the earliest Oligocene vertebrate assemblage of Monteviale (Vicenza, Italy)[END_REF].

Description-Although most of the skulls are generally complete or only partially incomplete, the deformation is so intense that it is not possible to evaluate all those characters needed to establish the degree of inclination or orientation of structures (e.g. the direction of the internal choana or the orientation of the basioccipital under the occipital condyle).

Seven of the ten skulls housed in Padua preserve the lower jaw compressed against the maxilla, covering the maxillary teeth. MGP-PD 10170 is significantly affected by the pyrite oxidation and therefore not informative. Only MGP-PD 26816 preserves the lower jaw (labelled as MGP-PD 26817) isolated from the skull, but due to deformation, the contacts among the bones of the mandible are not perceivable. The best preserved skull is the one reported in Figure 3 in which the suture pattern -at least the dorsal one -can be almost completely reconstructed.

From an overall perspective, the skulls are relatively broad, presenting wide premaxillae, a curved maxillary contour at the level of the largest teeth, and diminutive orbits.

However, the rostrum is quite elongate, the interorbital space is relatively narrow and the skull table is not expanded laterally and does not project posteriorly.

The anterior region of the rostrum is massive with an almost straight anterior margin of the premaxillae. The external nares are nearly rectangular, being slightly longer than wide.

The external nares are slightly smaller than the orbit. As it is particularly clear in MGP-PD 26862, the posterolateral margin of the nares is elevated and the anterior region of the rim of the nares is flat and continuous with the external margin of the bone. All the skulls and the fragments of rostrum present the same suture pattern, described below. The nasals are clearly excluded from the posterior margin of the nares by the premaxillae as these bones are anteroposteriorly expanded at the level of the premaxillary-maxillary notch. The premaxillary-maxillary suture is delineated by a pronounced embayment for reception of the third and fourth dentary teeth. At the level of the double caniniform tooth, the lateral maxillary margin is inflated. The nasals extend along most of the rostrum length. They taper anteriorly between the premaxillae, which send a short posterior process between the maxilla and nasal at the level of the first or second maxillary alveoli. The sutural pattern of the antorbital region is obscured in most of the specimens, but in two specimens, reported in Figure 3 and Figure 4 (A,B), which preserve the area clearly, the frontal separates the posterior tips of the nasals. The left side of NMB-Bc.6 indicates that the lacrimal tapers relatively far anteriorly at about the level of the sixth maxillary alveolus and therefore extensively contacts the posterolateral margin of the nasal. The prefrontal is not clearly distinguishable in any of the skulls.

The orbital region is characterized by a narrow interorbital width and small orbits. The anterior projection of the frontal is narrow (Figs 3,4B). The interorbital region is marked by a well-delineated preorbital ridge passing through the frontal and following the anteromedial margin of the orbits on the prefrontal and lacrimal (Figs 3 and4C). The interorbital region could seem different in Fig. 3A and Fig. 4C, but the different shape in Fig. 4C is due to a taphonomic effect. In fact, in Fig. 4C the anterior process of the prefrontal is detached and raised from the lacrimals surrounding it. The anterior-most margin of the orbits is formed by the lacrimal and is notched. This notch marks a depression, where the ornamentation is absent. The teardrop-shaped supratemporal fenestrae are well preserved in MGP-PD 28164 (Fig. 5), 26843, 26858 (Fig. 4C) and NMB-Bc.6 (Fig. 3). In NMB-Bc.6 and in MGP-PD 28164, the frontoparietal suture clearly penetrates the supratemporal fenestrae, preventing the postorbital from contacting the parietal on the skull table. The parietal is particularly wide between the supratemporal fenestrae, being almost as wide as each fenestra. The supraoccipital participates in the dorsal surface of the skull table and, even if the anterior part of its suture with the parietal is not clearly visible in any of the specimens, it surely does not prevent the parietal from reaching the posterior margin of the table. The squamosal prongs are short and do not project far posteriorly nor laterally, as particularly evident in NMB-Bc.6.

The suture organization around the lower temporal fenestra is poorly visible in most of the specimens, because of the deformation they have been subjected to. The lower temporal fenestra seems narrow and elongate, but this may be an artefact of compression. The quadratojugal seems to form the posterior corner of this fenestra and extend along its dorsal margin, therefore excluding the quadrate from it. A small quadratojugal spine can be reconstructed to have been located near the dorsal level of the lower temporal fenestra, but it is not preserved in any specimen. The postorbital bar is barely visible (e.g. in MGP-PD 26814 and in NMB-Bc.6) because it is hidden by other bones due to deformation. The jugal projects far posteriorly, but does not prevent any lateral exposure of the quadratojugal, particularly evident in Figure 3. The small medial quadrate hemicondyle bears the notch for the foramen aëreum on its dorsal surface, as evident in most of the specimens (e.g. MGP-PD 26814, 26816, 26835, NMB-Bc. 6).

The palatal structure cannot be entirely reconstructed. The paired palatines comprise the median walls of the suborbital fenestrae. Their anterior part is never visible and thus the anterior extension of the suborbital fenestrae cannot be understood. The posterior part of the suborbital fenestrae are particularly well preserved in MGP-PD 26858 (Fig. 4D) and partially preserved in NMB-Bc.6. The palatines have parallel margins and there is no lateral flaring of each bone (Fig. 4D). The palatine-pterygoid suture is located well ahead of the posterior corner of the suborbital fenestra (Fig. 4D). The lateral edges of the palatines are parallel posteriorly, without producing a shelf. The pterygoid edge contributing to the posterior rim of the suborbital fenestra does not show any notch. The internal choanae open in the central region of the pterygoids. Their lateral margins form a collar, the pterygoid being depressed lateral to it (particularly visible in MGP-PD 26844). The anterior extension of the ectopterygoid is unclear. The ventral ectopterygoid process is massive and does not project all the way to the tip of the pterygoid wing. Instead, it stops at more than half the distance, as visible in Figure 6D and NMB-Bc.6.

The mandibles are often associated, and articulated, with the skulls, but because of the strong deformation that they have suffered they are usually opened at the level of the contact between splenial and dentary (so that the external surface of the dentary and the internal surface of the splenial are exposed). Moreover, even if the bones are generally identified, most of the characters important for the identification are unperceivable. For example, the articular elements are very common among the Padua specimens, but the foramen aëreum is in most cases not visible. The mandibular symphysis is often visible -particularly well in Figure 6 (B, C, E, F) -and it extends to the 4 th mandibular tooth. The surangular is pinched off anterior to the posterior extent of the retroarticular process in MGP-PD 26814. The retroarticular process is deeply concave and its tip projects posterodorsally.

The total number of teeth cannot be assessed. The maxillary teeth are at least 13 in MGP-PD 26844. When the dental pattern can be reconstructed, it emerges that the largest maxillary alveoli are the 4 th and 5 th , which are confluent. In MGP-PD 26815 and 26844, the 4 th alveolus seems slightly smaller than the 5 th (Fig. 2). The implication of this character will be discussed in the next section. The 6 th tooth is considerably smaller than the 5 th one. The 4 th dentary alveolus is the largest, and its tooth is hosted in the notch corresponding to the maxilla-premaxilla suture. Even if the 3 rd tooth is not preserved in any specimen, the maxillary notch is wide enough to host two dentary teeth in occlusion, corresponding to the 3 rd and 4 th confluent dentary alveoli. The occlusion is comparable to that of other species of Diplocynodon and can be reconstructed particularly well in MGP-PD 8648. In this specimen, the maxilla is fractured in the two points in which the maxilla is notched, after the 4 th mandibular tooth and after the 7 th maxillary tooth.

Limited information can be gained from the postcranial elements. Among the Padua material, there are several portions of postcranial elements, but they are usually poorly preserved, or particularly altered. The vertebral column cannot be entirely reconstructed, because all the remains are fragmentary, and some parts of the vertebral column (i.e. the cervical vertebrae) are poorly preserved. The atlas is only preserved, but disarticulated, in NMB-Bc.6, which also preserves the axis and the third cervical vertebra in lateral view (Fig. 3C). Another axis is preserved (MGP-PD 26856), but its anterior crest is broken in both cases.

The limbs and the pelvic and scapular girdle are also very fragmentary, even if in some cases still articulated. These elements were dissociated before burial of the animals as testified by the incompleteness also of NMB-Bc.6, which lacks the posterior trunk region. A similar pattern can be observed in the La Rochelle skeleton where only the left forelimb is still partially articulated and most of the dorsal osteoderms and the trunk vertebrae are missing.

Noteworthy is the organization of the dorsal armor in the trunk region of NMB-Bc.6, where neural arches are visible, indicating the midline of the trunk (Fig. 7A,B). Herein is also visible a lateral osteoderm and it is therefore possible to clearly identify where the dorsal osteoderms stop. Each row of dorsal osteoderm can be thus reconstructed as containing six osteoderms (Fig. 7B). The dorsal midline osteoderms bear anterior process (Fig. 7C). The ventral armor is visible in lateral view in Figure 7 (D,E), where the ventral, bipartite osteoderms are clearly visible, and one ischium is also detectable (Fig. 7F). The distal portion of the shaft is greatly expanded; the maximum diameter of this expansion is oblique in position. The entire external surface of the ischium is somewhat convex. Each series of osteoderms overlaps the next series located posterior to it.

RESULTS

Provenance Analysis

Results are presented in Table 1 andFigure 8. The most radiogenic values were measured on the two samples from Purga di Bolca (average = 0.732). These differ significantly from the rest of the samples measured here (average = 0.711), including the two samples from Monteviale (MGP26855 and MGP26836), the samples from Basel and La Rochelle, and surprisingly the sample NHM-UK 2789 originally labelled as coming from Purga di Bolca.

Taxonomic Identification

The specific assignment to Diplocynodon ratelii by Brinkmann and Rauhe (1998), Del [START_REF] Favero | Un esemplare di Diplocynodon Pomel, 1847 (Crocodylia, Leidyosuchidae) conservato nel museo geopaleontologico dell[END_REF] and [START_REF] Pandolfi | Reassessing the earliest Oligocene vertebrate assemblage of Monteviale (Vicenza, Italy)[END_REF] is not accepted here, as discussed below. The organization of the sutures of the skull is basically the same as D. tormis from the Eocene, and D. muelleri from the Oligocene, of Spain [START_REF] Buscalioni | A new species of the eusuchian crocodile Diplocynodon from the Eocene of Spain[END_REF][START_REF] Piras | Diplocynodon muelleri comb. nov., an Oligocene diplocynodontine alligatoroid from Catalonia (Ebro Basin, Lleida province, Spain)[END_REF]. Besides being the same age, D. muelleri and the Monteviale crocodilians share the shape and proportions of the skull table, which bears teardrop-like supratemporal fenestrae (for D. muelleri see holotype in fig. 3 in [START_REF] Piras | Diplocynodon muelleri comb. nov., an Oligocene diplocynodontine alligatoroid from Catalonia (Ebro Basin, Lleida province, Spain)[END_REF], whereas in D. tormis they are more elliptical (see holotype in fig. 2 in [START_REF] Buscalioni | A new species of the eusuchian crocodile Diplocynodon from the Eocene of Spain[END_REF]. Moreover, the parietal between them is not as thin as in D. tormis, where each fenestra is twice as wide as the parietal. In the Monteviale specimens and D. muelleri, the parietal is about the same width as each fenestra. [START_REF] Piras | Diplocynodon muelleri comb. nov., an Oligocene diplocynodontine alligatoroid from Catalonia (Ebro Basin, Lleida province, Spain)[END_REF] stated that D. muelleri shows a particularly short mandibular symphysis reaching the third mandibular alveolus. In this respect, the Monteviale specimens differ from it, as the symphysis reaches the fourth alveolus. However, in the holotype of D. muelleri (NMB-Spa.4), housed in Basel, the mandible is broken at the level of the mandibular symphysis and it is therefore impossible to evaluate its extension. In D. muelleri NMB-Spa.73, the symphysis does not seem shorter than the one of the Monteviale specimens. A revision of the symphyses of all the specimens of D. muelleri is needed, but, at the state of the art, this character is not considered sufficient to distinguish between the Spanish species of Diplocynodon and the Monteviale crocodilian. The maxillary dentition pattern can be reconstruced only in two specimens from Monteviale (MGP-PD 26844 and MGP-PD 26815), which show the typical confluent 4 th and 5 th alveoli, but, differently from the other species of Diplocynodon, the 4 th alveolus seems slightly smaller than the 5 th (Fig. 2).

Even if this character state is also found in Asiatosuchus-like crocodyloid taxa, the rest of the anatomy agrees with placement of these specimens in Diplocynodon. However, this feature could be only due to intraspecific variability and it seems more cautious to not consider it significant enough to attribute the material to a species separate from the others.

Phylogenetic Analysis

As in [START_REF] Martin | Late Palaeocene eusuchian remains from Mont de Berru, France, and the origin of the alligatoroid Diplocynodon[END_REF], two analyses were carried out: including the two less complete species of D. ungeri and D. elavericus and excluding them. The topology and the nodal support metrics are in both cases consistent with the results of [START_REF] Martin | Late Palaeocene eusuchian remains from Mont de Berru, France, and the origin of the alligatoroid Diplocynodon[END_REF]. The Diplocynodon group has a Bremer (decay) index of one, but it is supported by seven unambigous synaphomorphies (characters 14, 33, 41, 68, 81, 148, 152 of Brochu et al., 2012).

As in [START_REF] Martin | Late Palaeocene eusuchian remains from Mont de Berru, France, and the origin of the alligatoroid Diplocynodon[END_REF], including the less complete species, the tree shows a polytomy at the basis of Diplocynodontidae (topology not reported herein), leaving unresolved the relationships among its members. The analysis excluding the less complete species retained 640 trees [consistency index (CI) = 0.3412; retention index (RI) = 0.8021]. For clarity of reading, the strict consensus tree excluding the less complete species (Fig. 9) has been simplified for some clades (i.e. Gavialoidea, Globidonta, and Crocodyloidea). The Monteviale species is placed in a derived position, in a polytomy with D. tormis and D. muelleri, that is the sister group of D. ratelii.

DISCUSSION

Provenance Analysis

The present geochemical approach relies on a comparative assessment of the radiogenic strontium isotope values of two lignites from two localities. The 87 Sr/ 86 Sr composition of lignites for provenance purposes has not been widely used in paleontology and heterogeneity of the lignites may be problematic. Nevertheless, values obtained in the sample size available to fall into two groups. Our small sample size precludes statistical analysis. The strontium isotope values measured in the sediment depend on the age and lithology of the bedrock source. The high ratios measured in Purga di Bolca samples indicate a highly radiogenic source, possibly an old granitic substrate. On the other hand, the lignite from Monteviale was sourced from bedrock of a different composition. Results show that the lignite matrix surrounding the crocodile specimens housed in the Musée de La Rochelle, NMB Basel and NHM-UK London have strontium isotope ratios comparable to the samples analyzed from the Oligocene locality of Monteviale. It seems reasonable to consider these specimens as originating from Monteviale unless further analyses show otherwise.

Affinities of the Oligocene Crocodilians from Monteviale

After the revision of all the available crocodilian remains, it is clear that the Monteviale material belongs to a single species of Diplocynodon, as previously suggested [START_REF] Rauhe | News about fossil crocodiles from the Middle Eocene of Messel and Geiseltal, Germany[END_REF][START_REF] Kotsakis | Italian Cenozoic crocodilians: taxa, timing and biogeographic implications[END_REF][START_REF] Pandolfi | Reassessing the earliest Oligocene vertebrate assemblage of Monteviale (Vicenza, Italy)[END_REF]. In fact, it shares the diagnostic characters of this genus: anterior process of the dorsal osteoderms, bipartite ventral osteoderms (Fig. 7E), a pair of caniniform teeth hosted in confluent alveoli (maxillary teeth 4 and 5; Fig. 2), and the presence of a preorbital ridge (Fig. 3; [START_REF] Martin | Late Palaeocene eusuchian remains from Mont de Berru, France, and the origin of the alligatoroid Diplocynodon[END_REF]. This differs from Asiatosuchus-like crocodyloid taxa, which have a single enlarged fifth maxillary tooth and lack the preorbital ridge and the bipartite, ventral osteoderms [START_REF] Delfino | A reassessment of the morphology and taxonomic status of 'Crocodylus' depressifrons Blainville, 1855 (Crocodylia, Crocodyloidea) based on the Early Eocene remains from Belgium[END_REF]. Also, while both the Monteviale species of Diplocynodon and Asiatosuchus have small orbits compared to their skull size, the interorbital width in Asiatosuchus is much larger. The position of the frontoparietal suture does not seem to discriminate any affinity. In species of Diplocynodon and Asiatosuchus germanicus, the suture makes a deep entry in the supratemporal fenestra [START_REF] Brochu | Phylogeny, systematics, and historical biogeography of Alligatoroidea[END_REF] whereas in A. grangeri and Asiatosuchus depressifrons, the suture lies entirely on the skull table [START_REF] Delfino | A reassessment of the morphology and taxonomic status of 'Crocodylus' depressifrons Blainville, 1855 (Crocodylia, Crocodyloidea) based on the Early Eocene remains from Belgium[END_REF]; but see also Delfino et al., 2017, for the morphology of the oldest European Asiatosuchus). In the Monteviale specimens the suture makes a deep entry in the supratemporal fenestrae, a condition currently unknown in Asiatosuchus spp. The position of the foramen aëreum observed in the Monteviale species of Diplocynodon differs from that of Asiatosuchus and Asiatosuchus-like taxa for which the foramen aëreum is medially shifted. Here, this foramen is placed on the dorsal surface of the quadrate.

In Asiatosuchus the mandibular symphysis is long, extending at least to the sixth dentary alveolus [START_REF] Leriche | Note sur le Crocodilus depressifrons trouvé à Urcel (Aisne)[END_REF][START_REF] Mook | A new fossil crocodilian from Mongolia[END_REF][START_REF] Berg | Die Krokodile, insbesondere Asiatosuchus und aff. Sebecus?, aus dem Eozän von Messel bei Darmstadt/Hessen[END_REF][START_REF] Vasse | Un crâne d'Asiatosuchus germanicus du Lutétien d'Issel (Aude). Bilan sur le genre Asiatosuchus en Europe[END_REF][START_REF] Delfino | A reassessment of the morphology and taxonomic status of 'Crocodylus' depressifrons Blainville, 1855 (Crocodylia, Crocodyloidea) based on the Early Eocene remains from Belgium[END_REF]Delfino et al., 2017). On the contrary, in species of Diplocynodon the symphysis extends between the third and the fourth dentary alveoli and is therefore shorter. The morphology exhibited by all the skulls from Monteviale clearly shows the condition found in species of Diplocynodon, extending the dentary symphysis to the fourth alveolus (e.g., MGP-PD 26843, MGP-PD 26844, MGP-PD 26814, MGP-PD 26815). The 3 rd and 4 th dentary alveoli, which are confluent in the species of Diplocynodon, are not visible in any case, but the corresponding maxillary notch is wide enough to host two teeth. The marked premaxillary-maxillary notch is not diagnostic for Asiatosuchus, as it is present in several species of Diplocynodon. This feature develops during ontogeny, as observed for D. hantoniensis [START_REF] Owen | Fossil Reptilia of the London clay. Part II-Crocodilia and Ophidia[END_REF][START_REF] Norell | The Late Cretaceous allligatorid Brachychampsa montana (Crocodylia): new material and putative relationships[END_REF], D. ratelii [START_REF] Berg | Die Krokodile, insbesondere Asiatosuchus und aff. Sebecus?, aus dem Eozän von Messel bei Darmstadt/Hessen[END_REF][START_REF] Brochu | Phylogeny, systematics, and historical biogeography of Alligatoroidea[END_REF], D. muelleri [START_REF] Piras | Diplocynodon muelleri comb. nov., an Oligocene diplocynodontine alligatoroid from Catalonia (Ebro Basin, Lleida province, Spain)[END_REF] and probably for most other species of Diplocynodon.

From a strictly osteological comparisons, there is no reason to support the option that Asiatosuchus was present at Monteviale [START_REF] Franco | A small crocodilian species from the Oligocene of Monteviale in Vicentinian, Asiatosuchus monsvialensis (Fabiani, 1914)[END_REF] and the morphological uniformity of all the available material indicates that only one taxon is present. In fact, specimens which are only represented by anatomical elements not preserved on the types of D. muelleri or which, for preservational reasons, do not bear any diagnostic character are tentatively referred to the only species present in Monteviale, because they do not differ in morphology and size from Diplocynodon. This is also confirmed by the phylogenetic analysis which places the Monteviale crocodilian in a derived position nested among the other species of Diplocynodon. Indeed, all the remains from Monteviale presented in the literature should be ascribed to the genus Diplocynodon. This observation is also consistent with the known stratigraphic range of the genus Asiatosuchus, the latest unambiguous occurrence of which is from the Late Eocene (Bartonian) of Camburg, Germany [START_REF] Vasse | Un crâne d'Asiatosuchus germanicus du Lutétien d'Issel (Aude). Bilan sur le genre Asiatosuchus en Europe[END_REF].

As far as the specific assignment is concerned, the previous specific attribution to D. ratelii [START_REF] Brinkmann | Diplocynodon ratelii Pomel, 1847 (Crocodylia, Leidyosuchidae) aus dem unter-Oligozän von Céreste (Südfrankreich)[END_REF] and D. cf. ratelii [START_REF] Pandolfi | Reassessing the earliest Oligocene vertebrate assemblage of Monteviale (Vicenza, Italy)[END_REF] is not confirmed. In fact, in D. ratelii the nasals clearly reach the external nares (Díaz Aráez et al., 2017), whereas in the studied material the nasals stop at least one centimetre away from the nares (Figs 3B,4B,5B). This is also confirmed by the phylogenetic analysis carried out, which retrieved the Monteviale specimen in a polytomy with the two Spanish species of D. tormis [START_REF] Buscalioni | A new species of the eusuchian crocodile Diplocynodon from the Eocene of Spain[END_REF] and D. muelleri [START_REF] Piras | Diplocynodon muelleri comb. nov., an Oligocene diplocynodontine alligatoroid from Catalonia (Ebro Basin, Lleida province, Spain)[END_REF], forming together the sister group of D. ratelii. The morphology and the suture organization are very similar to those of D. tormis and D. muelleri. Diplocynodon tormis is an alligatoroid found in the Eocene of Iberia [START_REF] Buscalioni | A new species of the eusuchian crocodile Diplocynodon from the Eocene of Spain[END_REF], whereas D. muelleri comes from the Oligocene of the same area [START_REF] Piras | Diplocynodon muelleri comb. nov., an Oligocene diplocynodontine alligatoroid from Catalonia (Ebro Basin, Lleida province, Spain)[END_REF]. These two species are very similar, showing no difference in the suture pattern of the skull. The general shape of the skull is asserted to be different by [START_REF] Piras | Diplocynodon muelleri comb. nov., an Oligocene diplocynodontine alligatoroid from Catalonia (Ebro Basin, Lleida province, Spain)[END_REF], but this difference is most likely due to the fact that D. muelleri is dorso-ventrally compressed because of taphonomic processes, in a similar way of the Diplocynodon of Monteviale, whereas D. tormis, not being dorsoventrally compressed on a slab, preserved better the three-dimensional aspect of the skull, seeming slender. The main differences pointed out by [START_REF] Piras | Diplocynodon muelleri comb. nov., an Oligocene diplocynodontine alligatoroid from Catalonia (Ebro Basin, Lleida province, Spain)[END_REF] concern the mandibular symphysis which they describe as particularly short in D. muelleri, reaching the third mandibular alveolus, and the palatal fenestrae which are described as particularly long in D. muelleri. Actually, a direct analysis of the D. muelleri holotype (NMB-Spa 4 T2) and another specimen (NMB-Spa 73) of this species, which are housed in Basel, indicated that these differences are not so evident. In fact, the holotype does not preserve the symphysis which is broken off and its palatal fenestrae are not clearly separated from the rest of the skull. The palatal fenestrae show a similar condition in NMB-Spa 73, but the symphysis is preserved and does not seem significantly less extended than in the Monteviale specimens, in which it reaches the 4 th mandibular alveolus. Another difference between D. muelleri and D. tormis is realated to the shape and proportion of the supratemporal fenestrae. The supratemporal fenestrae in D. tormis, in fact, are elliptical and wide, being twice as wide as the parietal between them, whereas in D. muelleri, they have a more teardrop-like shape and the parietal is wider between them. In this respect, the Monteviale specimens are more similar to D. muelleri than to D. tormis. Indeed, the supratemporal fenestrae are teardrop-like and the parietal is as wide as the fenestrae, as in D. muelleri. However, the skull table and the supratemporal fenestrae are known to change during ontogeny [START_REF] Iordansky | The skull of the Crocodilia[END_REF] and for this reason they are not widely used as important characters for taxonomy and phylogeny [START_REF] Brochu | Phylogeny, systematics, and historical biogeography of Alligatoroidea[END_REF]. A careful revision of the species D. tormis and D. muelleri is currently needed to confirm the validity of both species ; indeed they may represent the same species at different ontogenetic stages. Currently, the Monteviale alligatoroid can be considered more similar to D. muelleri than to D. tormis.

Implications for Crocodilian Turnover

Comparative osteology suggests that no evidence exists for the presence of crocodyloids in the late Early Oligocene of Monteviale. Several European Eocene localities include multiple species within a given environment [START_REF] Markwick | Fossil crocodilians as indicators of Late Cretaceous and Cenozoic climates: implications for using palaeontological data in reconstructing palaeoclimate[END_REF][START_REF] Martin | A new species of Diplocynodon (Crocodylia, Alligatoroidea) from the Late Eocene of the Massif Central, France, and the evolution of the genus in the climatic context of the Late Palaeogene[END_REF]. One hallmark example is the Messel oil shale locality (early Middle Eocene, MP 11, ca. 47 M.a.), which is composed of two generalist taxa of different size (the alligatoroid Diplocynodon darwini and the crocodyloid 'Asiatosuchus' germanicus), one or two terrestrial predators (the sebecid Bergisuchus dietrichbergi and the eusuchian Boverisuchus rollinati), and a diminutive tribodont (Hassiacosuchus haupti). This diverse assemblage thrived under the greenhouse climate during part of the Eocene. But climatic conditions drastically changed near the end of the Eocene [START_REF] Zachos | Trends, rhythms, and aberrations in global climate 65 Ma to present[END_REF][START_REF] Mosbrugger | Cenozoic continental climatic evolution of Central Europe[END_REF][START_REF] Escarguel | Unearthing deep-time biodiversity changes: The Palaeogene mammalian metacommunity of the Quercy and Limagne area (Massif Central, France)[END_REF][START_REF] Héran | Cenozoic long-term terrestrial climatic evolution in Germany tracked by δ 18 O of rodent tooth phosphate[END_REF]; the progressive development of cooler conditions and the marked temperature decline at the very end of the Eocene most probably influenced the distribution of ectothermic taxa and contributed to the diversity decline observed across the EOB in crocodilian assemblages. After this event, the continental fossil record indicates only the presence of species of Diplocynodon [START_REF] Antunes | Crocodilian faunal renewal in the upper Oligocene of Western Europe[END_REF][START_REF] Piras | Phylogenetic position of the crocodylian Megadontosuchus arduini (de Zigno, 1880) and tomistomine palaeobiogeography[END_REF]. Due to their physiological constraints, crocodilians have been used as climatic proxies for inferring the latitudinal gradient of temperatures and hygrometry in the past [START_REF] Markwick | Fossil crocodilians as indicators of Late Cretaceous and Cenozoic climates: implications for using palaeontological data in reconstructing palaeoclimate[END_REF]. Our results confirm this pattern: only one species exists in the Oligocene of Monteviale, namely a species of Diplocynodon, a taxon broadly encountered in the freshwater ecosystems of that epoch.

CONCLUSIONS

The radiogenic strontium isotope ratio analysis performed herein revealed itself successfull in ascertaining the provenance of the three previously unreported specimens Diplocynodon housed in collections in Basel, La Rochelle and London. This method can perhaps be applied to other specimens in general, and in particular to those specimens coming from north-east of Italy whose provenance is uncertain.

Following the morphological and taxonomic revision of all the available material, the crocodilians from Monteviale are assigned to a single species of the genus Diplocynodon, as previously proposed. There is indeed no evidence of Asiatosuchus-like taxa from the Oligocene of Monteviale, thus confirming a stratigraphic range for Asiatosuchus-like taxa restricted to the lower side of the Eocene-Oligocene boundary. Moreover, it seems likely that the only problematic specimen of Diplocynodon labelled as coming from Monte Bolca is actually coming from Monteviale. In fact, as said above, previous studies already underlined that nannofossils of the matrix of this specimen indicated a younger age than Eocene, compatible with Oligocene of Monteviale [START_REF] Favero | Un esemplare di Diplocynodon Pomel, 1847 (Crocodylia, Leidyosuchidae) conservato nel museo geopaleontologico dell[END_REF][START_REF] Kotsakis | Italian Cenozoic crocodilians: taxa, timing and biogeographic implications[END_REF].

Furthermore, after our study, the morphological similarity between this single specimen labelled as coming from Monte Bolca and the Monteviale crocodilian is clear and thus the presence of a species of Diplocynodon in Monte Bolca seems to be unsubstantiated. The The material from Padua is described first and subdivided among: (i) complete (or nearly so) skulls, (ii) variably isolated skull elements, and (iii) postcranial elements.

As the Basel, La Rochelle, and London specimens are basically large slabs on which there are whole parts of the individuals, they will be described at the bottom of this section, after the material of Padua. The skeleton housed in the Musée d'Histoire Naturelle of La Rochelle, France is almost complete and gives a good idea of the total length of the animal, although several parts of the postcranial skeleton are not preserved. The skull is complete and visible in dorsal view.

Complete skull

MGP-PD 10170

This catalogue number refers to a skull completely destroyed by the pyrite oxidation. It is now represented by several indistinguishable fragments.

MGP-PD 28164

This catalogue number refers to an almost complete compressed skull with the lower jaw in ventral view (Fig. 5). A transverse fracture extends about halfway through the nasals, so the specimen is composed of two parts. The premaxilla is fractured at the level of the anterior half of the nares, thus the anterior edge of the rostrum is missing. The left side of the posterior part of the cranium (made up of the left quadrate, jugal and quadratojugal) is also missing. The anterior part of the suture between maxillae and nasals is visible, as is the suture between nasals and premaxillae, showing clearly that the nasals do not enter the external nares (Fig. 5B). The prefrontal and lacrimal region is quite obscure because of the deformation and of the liquids used to preserve the specimen.

Moreover, the lacrimals are incomplete. The supratemporal fenestrae are teardrop-shaped and long, occupying almost half of the length of the neurocranial table. The neurocranium is only visible in dorsal view and has a very resinous aspect because of the varnish applied to it: most of the sutures are not visible, but the sutures between the frontal and the left postorbital, and between the frontal and the parietal, are appreciable (Fig. 5C). The right squamosal is fractured and slightly tilted. The posterior concavity of the squamosal is wide, with a clear tip laying on the paraoccipital process of the exoccipital.

Ventrally, the palatines are visible but in the area of the neurocranium the morphology is quite obscure and no character is distinguishable. The lower jaw shows a symphysis that extends approximatively to the 4 th dentary alveolus.

MGP-PD 26814

This catalogue number refers to the lectotype of Diplocynodon dalpiazi [START_REF] Fabiani | Il Paleogene del Veneto[END_REF]. It is an almost complete skull, also with the lower jaws visible in ventral view, but is very deformed. In addition to the dorsoventral depression typical of all the Monteviale specimens, this skull has been exposed to remarkable lateral compression, so the left part of the skull, preserving the left external lower jaw, is well visible, whereas the right part is not distinguishable (Fig. S1D). It is one of the largest skulls, reaching at least 32 cm in length, but no suture is visible because the effect of the pyrite oxidation altered its fine morphology. The postorbital fenestra is triangular with a very short postorbital bar. The orbit is small: just under 4 cm in length and 3 cm in width. The skull is also incomplete at the level of the left lacrimal, but it might be possible to see part of the sutures between this bone and the adjacent nasal and jugal. The left squamosal is less deformed than the rest of the skull. The posterolateral process of the squamosal is uplifted respect to the skull table.

There is probably a dislocation at the level of the suture between left quadrate and squamosal. The left articular and quadrate with the quadrate notch corresponding to the foramen aëreum are easily distinguished. The jugal is notably enlarged at the level of the postorbital bar.

Ventrally, the palate is strongly damaged and deformed. The left pterygoid, and partially the right one, are fully visible. The ectopterygoid is broken in undistinguishable from the pterygoid because of the action of the pyrite oxidation. The right mandible is almost complete, even if partially incomplete, in its posterior part, because there is a fracture that crosses the specimens at the level of the external mandibular fenestra. Here, we are able to count at least 14 (or 15) tooth positions. The left mandible has been tilted to the point that its medial surface is visible in ventral view-with the well-preserved articular element-and its external part is visible in dorsal view. The surangular-dentary contact is visible in the posterior part of the right mandible. The posterior-most part of the dentary is broken off, but the surangular shows a clear posterior tip ending anterior to the retroarticular process (character 72: 1).

MGP-PD 26815

This catalogue number refers to an incomplete anterior portion of a rostrum (Fig. S1E-F, 2C-D, 6E-F). Its bones are very thick, larger than those of the other specimens, so it probably belongs to an old, morphologically mature individual. The rostrum fragment preserves the lower jaw and the maxillary dentition on its ventral surface. The dentary symphysis extends to the 4 th dentary alveolus. The 5 th maxillary tooth is large, the 4 th tooth is absent, but the alveolus seems slightly smaller than the 5 th . The palatines are not recognizable since it is impossible to identify the sutures between palatine and maxillary elements, indicated by Franco et al. (1992, tav. III, 2).

MGP-PD 26816 -26817

These two specimens are described together because they represent the cranium and lower jaw of the same individual. The cranium is separated in two parts by a fracture that passes through the orbits. The anterior part is nearly complete, whereas the posterior one is highly fragmented, with the jugal area of the skull missing on both sides. The nasals are short and therefore do not enter the external nares, as they stop at least two alveoli posterior to the posterior rim of the nares. Several alveoli of the right maxilla are visible: at least 12 maxillary and 4 premaxillary teeth are preserved and visible. The premaxillary-maxillary suture ends in the notch corresponding to the 4 th dentary tooth. The foramen incisivum is not very wide and it is far from the teeth. The skull table is crossed by a fracture at the level of the left supratemporal fenestra. The left squamosal is entirely missing, whereas the right one is broken off in the part that contacted the parietal. The left region is slightly more complete than the right one, as part of the quadrate is preserved in connection with the articular (and possibly the surangular), whereas part of the right quadrate is only preserved as a separate fragment, together with part of the quadratojugal. In this fragment, the dorsal notch of the quadrate for the foramen aëreum (character 179: 1) is visible. As far as the attachment scar for the posterior mandibular adductor muscle on the ventral surface of the quadrate is concerned, it can be reconstructed to have been present as a modest crest (character 178: 0), through the whole crest is not present, but only its posteriormost part.

The lower jaw is highly deformed and incomplete so that the detailed morphology cannot be assessed. It was also broken in two points, but was subsequently reunited. Even if the dental alveoli are not visible, it can be stated that the two fractures passed more or less at the level of the 5 th right alveolus and of the 7 th left one.

MGP-PD 26843

MGP-PD 26843 is the lectotype of Asiatosuchus monsvialensis [START_REF] Fabiani | La serie stratigrafica del Monte Bolca e dei suoi dintorni[END_REF]. This specimen is an almost complete skull, dorsoventrally depressed (Fig. S1A-B, 6A-C). The lateral deformation seems to be negligible. Surprisingly, the anterior end of the nasals has been figured by Franco and Piccoli (1993: pl. I,1) as reaching the external nares, whereas they are actually at least 12 mm far from each other. The relationship among nasals, prefrontals, and frontal is consistent with the specimens described above. The sutures of the lacrimals are not clearly visible. The jugal is dorsoventrally enlarged at the level of the postorbital bar, even if not as much as in the specimen 26814: in this case, it is slender. The jugal and the quadratojugal are slightly disarticulated at the level of the evident suture, whereas the suture between quadrajugal and quadrate is only perceivable. In ventral view, the surface of the skull is significantly altered and, even if some areas are more discernible (e.g. the posterior part of the palatines showing reciprocal contact), the general morphology of the palate cannot be assessed.

MGP-PD 26844

This is a quite complete skull aside from the missing left postorbital region (Fig. 2A-B). It is very compressed dorsoventrally and it is one of the skulls most treated with varnish, to the point that, especially in dorsal view, almost nothing can be said about its morphology and sutures. Ventrally, the posterior part of each palatal fenestra is visible. The dental pattern can be reconstructed in the left maxilla, which bears at least 13 alveoli, with the 4 th and the 5 th alveolus confluent but with the 4 th smaller than the 5 th .

MGP-PD 26845

This skull is affected by severe deformation. The anterior part of this skull is broken off and the cranium is significantly deformed, with a marked lateral deformation, which obliterates most of the left part of it (Fig. S1C). The right portion of the skull is represented by the jugal with an evident infratemporal fenestra and by part of the parietal table, making up the supratemporal fenestra. The anteromedial edge of the orbits is elevated in a crest, which, together with the frontal step forms the spectacle. Ventrally, the deformed mandible occupies most of the space, and the palatal structure cannot be reconstructed.

MGP-PD 26846

MGP-PD 26846 is a skull highly fractured and intensively treated with varnish. The anterior portion of the rostrum is missing, and so are both lateral sides. Because of the extensive painting which covers the bones, no characters are scorable on this specimen.

MGP-PD 26850

This catalogue number refers to the anterior part of a skull broken at the level of the anterior edge of the orbits. The external nares are not bisected by the nasals, which are excluded by the nares (character 82: 2). It is one of the skulls where the sutures are the clearest: all the sutures of the nasals and the sutures between prefrontal and lacrimals are easily distinguished (Fig. 4A-B). The lacrimal makes broad contact with the nasal and there is no posterior process of the maxilla (character 127: 0). The prefrontal is uplifted in its posterior part, forming part of the bony eyelid, typical of alligatoroids.

Ventrally, the dentary symphysis extends, as in the other specimens, to the 4 th dentary tooth.

MGP-PD 26858

This catalogue number refers to a skull affected by significant deformation, in which the anterior right part of the rostrum is missing (Fig. 4C-D). The deformation is clear at the level of the orbits, which look very different in shape from one another; the left is more triangular than the right one.

The postorbital bar is short and hidden by the displaced surrounding bones (as in MGP-PD 26814).

The neurocranium is relatively well preserved, showing the typical wide supratemporal fenestrae.

The sutures between the postorbitals and the prefrontal are clearly visible; in particular, in the left area these two bones are separated at the level of the suture. The contact between the left jugal and quadratojugal is visible, but the infratemporal fenestra is dorsoventrally depressed and thus it is not possible to evaluate if the suture between them lies ventrally, dorsally, or corresponding to the posterior angle of the fenestra (character 140). In lateral view, cervical vertebrae are evidently deformed and mostly covered by disarticulated osteoderms. Ventrally, the palatal region is partially covered by the highly deformed left mandible, but there are some characters worth noting. In fact, the posteromedial part of each suborbital fenestra is well preserved (Fig. S1D) and it can be discerned that the palatine-pterygoid suture is far from the posterior corner of the suborbital fenestra (character 117: 1) and that the lateral edges of the palatines are parallel posteriorly, without producing a shelf (character 119: 0). Moreover, even if the choana is not visible, the anteriormost part of the pterygoid contacting the palatine is intact, meaning that the choana is entirely surrounded by pterygoids (character 120: 1; Fig. S1D). The pterygoids are broken next to the base on both sides. Posterior to the cranium, there is also the proximal part of a humerus, with two skeletal elements. For the description of this specimen's hindlimb portion, see below (postcranium section).

Variably isolated skull elements

Besides the numbered specimens described in this section, there are seven fragments of mandibles and maxillae and more than 40 disarticulated teeth that do not have any catalogue number. Because of their highly fragmentary nature, the description is omitted but they have been examined, and, as their morphology is congruent with the described, numbered specimens, they have not been listed here.

MGP-PD 8648

MGP-PD 8648 is a right maxilla in occlusion with the lower jaw. The maxilla is fractured in two points, in those points in which the maxilla is notched, and therefore weaker than in the other areas:

after the 4 th mandibular tooth and after the 7 th maxillary tooth (Fig. 8). The dentition pattern can be evaluated better than in all the other specimens. The 4 th mandibular tooth is inserted in the typical premaxillary-maxillary notch. The premaxillary teeth are five, and because the only ontogenetic change can be a reduction in number (from five to four), character 87 (number of premaxillary teeth) is scored as 0 (5 premaxillary teeth). There are at least 12 maxillary teeth. The 4 th maxillary tooth projects from the alveolus, seeming larger than the 5 th , but actually, the 5 th alveolus is clearly larger than the 4 th .

MGP-PD 26819

This catalogue number refers to three very deformed fragments of a right maxilla and lower jaw in occlusion. One of the fragments preserves part of the mandibular symphysis, whose extension cannot be reconstructed because of the high level of deformation of the specimen. The medial internal surface is badly preserved and the anterior extension of the splenial is not visible. A few alveoli are still preserved but due to the incompleteness of the tooth row it is not possible to add further details.

MGP-PD 26835

MGP-PD 26835 is the posterior, left portion of a skull, with the posterior part of the lower jaw still in anatomical position. Dorsally, next to the teardrop-like supratemporal fenestra, the suture between the postorbital and the squamosal can be discerned. The suture between quadrate and quadratojugal is visible at least in the area near the articular process. Ventrally, the choana is central in the pterygoid. The notch of the quadrate is particularly evident.

MGP-PD 26837

This catalogue number refers to a portion of maxilla and lower jaw pasted together in a non-anatomical position. The interpretation of the structures is thus impossible.

MGP-PD 26838

This catalogue number refers to two fragments of left and right mandible from a single specimen.

On the left mandible it is visible the part of the suture between splenial and dentary corresponding to an area far from the symphysis, and thus unfortunately no character can be scored.

MGP-PD 26839

MGP-PD 26839 refers to 40 disarticulated teeth. Their shape is the classic conical shape, slightly curved, with evident mesiodistal carinae. Their labial and lingual surfaces are smooth (although a hint of longitudinal ridges is present). In all teeth, the limit between the crown and the root is marked by a faint constriction. The crown can display numerous transverse lines representing growth marks.

MGP-PD 26842

This catalogue number refers to a fragment of mandible that still hosts three teeth in the alveoli. The specimen is covered by varnish, obscuring its morphology.

MGP-PD 26957

This catalogue number refers to a fragment of mandible (possibly the right one) with a clear portion of splenial, but unfortunately without any visible suture. There are three teeth, of which just one is complete. Moreover, an empty alveolus is present.

MGP-PD 26859

This specimen is a slab with a portion of the vertebral column and with the posterior part of a left mandible with the articular region of the skull. The quadrate is visible with a small foramen aëreum (character 176: 0) on its dorsal surface (character 175: 1). The foramen aëreum is not perceivable on the retroarticular process because of preservational reasons.

MGP-PD 26862

This catalogue number refers to a portion of undeformed left rostrum. Part of the left external naris is visible, and the anterior and lateral margins of it are developed into a marked crest (Fig. S2A-B-C). No teeth are visible. In the ventral part of the specimen there are several disarticulated osteoderms in various orientations.

MGP-PD 31998

This catalogue number refers to various fragments of unidentified maxillary parts and a portion of right pterygoid, particularly ruined. The ectopterygoid-pterygoid flexure is not present because the suture is rather straight (character 125: 0) and the ectopterygoid clearly does not extend to the posterior tip of the lateral pterygoid flange (character 126: 1; Fig. S2D,6D).

Postcranium

As for the parts of the cranium, there are several unnumbered specimens that have been examined and which are not reported in detail because they are mostly unidentified limb fragments, disarticulated osteoderms, or vertebrae. These specimens include five slabs with poorly prepared and damaged portions of the vertebral column, five isolated vertebrae, seven slabs with fragmentary and disarticulated limbs, several ribs and osteoderms.

MGP-PD 27999 and 26854

MGP-PD 27999 is a big slab containing the lumbar portion of an individual (Fig. S3A-C, Fig. 7D-F). The vertebral column is exposed in ventral view, composed by 8 vertebrae, of which 6 are still articulated. There is also a part of the disarticulated pelvic girdle. The single bones are difficult to interpret: the smaller bone perhaps represents the proximal part of the ischium with the distal part broken and moved forward, whereas the larger bone (shown in Fig. S3B) could be the pubis. There are also some portions of the ilium which are highly fragmented and disarticulated. Next to the pelvic girdle there are some thin long bones that can be interpreted as remains of the gastral apparatus. On the opposite part of the slab there are some fragments of ribs. The dorsal osteoderms, with the typical midline keel, are only visible in a single line of articulation and thus the number of lines of dorsal osteoderms cannot be reconstructed. The ventral osteoderms are articulated and clearly bipartite (Fig. S3C).

MGP-PD 26854 is complementary to MGP-PD 27999, representing the prosecution of the left side of this individual. In this slab, the line of keeled dorsal osteoderms continues and next to it there is a disarticulated zeugopodium, probably composed of the left radius and ulna, and a broken distal part of the humerus (Fig. S3A). The vertebral elements are represented just by the vertebral body.

MGP-PD 26818

This slab hosts at least one vertebra, some dorsal keeled osteoderms, and two partial disarticulated limbs including a humerus.

MGP-PD 26820

A fragmented, very altered specimen, which contains a lot of disarticulated osteoderms that obscure most of the underlying bones. The preserved long bones cannot be identified.

MGP-PD 26821

MGP-PD 26821 is a slab with a portion of vertebral column, some disarticulated ribs or gastralia, and numerous osteoderms (Fig. S3E). The vertebrae are at least five, in ventral view, and without hypapophysis. Most of the osteoderms are visible in ventral view. Only one of them is surely a dorsal vertebra, as it presents the typical keel.

MGP-PD 26822

This slab shows some disarticulated and fragmented bones of the pelvic girdle. Three girdle bones are recognizable: one ischium, with a concavity on the proximal part, and two pubes. Moreover, there is a chevron and two vertebrae, which could be the two sacral elements. The most complete of these vertebrae is preserved in ventral view and shows a vertebral body and a transverse process, whereas the other one is represented by a small fragment.

MGP-PD 28623

This catalogue number refers to a single slab fragmented in three portions, containing part of a vertebral column, a number of disconnected ribs, and several osteoderms (Fig. S3D). The vertebral column is composed of seven articulated vertebrae. On four vertebrae there are the hypapophyses, which are not present in the other three, which means that this part of the column is composed of dorsal vertebrae. In the right part of the column there are two dorsal osteoderms, whereas in the left part a lot of ventral osteoderms are present.

MGP-PD 26824

This catalogue number refers to a slab with fragmented, disarticulated bones, some of which unidentifiable, and osteoderms (Fig. S2E). Some of these bones are of the pelvic girdle (possibly an ischium and a pubis, but it is very difficult to say, because of the bad preservation of the specimen), and the proximal epiphysis of the femur.

MGP-PD 26825 -26830

These two catalogue numbers refer to a fragmented slab (Fig. S4A). MGP-PD 26830 is represented by an incomplete vertebral body in ventral view, with the right transverse process, part of a limb (probably part of the zeugopodium and of the autopodium), and an isolated, broken osteoderm. The vertebral body of MGP-PD 26830 is broken and fits perfectly the broken portion of a vertebra present in MGP-PD 26825. This vertebra is only slightly dislocated with respect to other two vertebrae present on the slab MGP-PD 26825. These two vertebrae, in ventral view, are procoelous, with both the transverse processes preserved, approximately as long as the vertebral body. Next to these vertebrae there is a chevron, which, together with the length of the transverse processes, suggests that they are caudal vertebrae. On this slab, there is also another portion of a vertebra, some disarticulated ribs, and a chevron.

MGP-PD 26826

This altered slab contains several osteoderms, some incomplete vertebrae, and disarticulated fragments of gastralia or ribs. The osteoderms cover most of the underlying portion of the bones, which are thus unidentified.

MGP-PD 26827

This very altered slab contains some damaged vertebrae and some disarticulated bones including osteoderms.

MGP-PD 26828

This small, very altered slab contains several disarticulated ventral and dorsal osteoderms, together with a long, unidentified bone.

MGP-PD 26829

This slab hosts a broken, proximal portion of the zeugopodium, probably a radius and ulna. The articular surface is not visible. The two bones partially overly one another.

MGP-PD 26831, 26832, 26833 and 26834

These catalogue numbers refer to different fragments belonging to the same individual. The fragments are small, and very altered because of pyrite. There are some ribs and several osteoderms, which obscure the other bones.

MGP-PD 26836

This catalogue number refers to a fragment of an elongated, unidentified bone.

MGP-PD 26840

Slab with a portion of a posterior limb and of the caudal vertebral column (Fig. S4E). The posterior limb is composed of a complete autopodium and zeugopodium, whereas the femur is broken at the level of the distal epiphysis. In the vertebral column, there are six vertebrae with the relative lateral osteoderms.

MGP-PD 26841

This catalogue number refers to a slab with an almost complete posterior limb with few isolated osteoderms (Fig. S4D). The femur and the zeugopodium are complete. The femur is slightly longer than the zeugopodium and curved in both its proximal and distal part. The autopodium is partially preserved.

MGP-PD 26847

MGP-PD 26847 is a slab with several articulated dorsal osteoderms. The osteoderms have the typical keel and are disposed in four parallel lines (Fig. S4B). Lateral to the osteoderms there is a wide and short bone that is probably a coracoid.

MGP-PD 26848

This catalogue number refers to a large slab with many disarticulated osteoderms, of which one is surely dorsal. The slab is ruined because of pyrite oxidation, and very little can be said about it. One unidentified bone of the scapular girdle is also present.

MGP-PD 26849

This slab hosts articulated.ventral and dorsal osteoderms. Moreover, there are at least ten vertebrae, of which 4 only slightly disarticulated. A portion of the anterior left limb is visible, with the humerus fractured in the proximal part, the zeugopodium and some disarticulated phalanges. The pelvic area is very altered and there are several fractured bones, including two disarticulated femora.

MGP-PD 26851

This slab preserves a fragmented anterior limb. The autopodium and the articulation between humerus and radius and ulna are missing. The proximal part of the humerus is broken and the characters of phylogenetic relevance are not visible.

MGP-PD 26852 and 26853

These two catalogue numbers refer to a single slab that contains several poorly preserved osteoderms (Fig. S4C). Among them, there are some unidentified bones and a limb, possibly anterior, in which the articulation between the stylopodium and the zeugopodium is clearly visible.

The autopodium is not visible, as it is covered by the osteoderms and partially broken off in its distal part.

MGP-PD 26855

This catalogue number refers to a very altered slab with some disarticulated osteoderms, four fragments of disarticulated ribs and a portion of a scapular girdle (Fig. S5A). The two flat bones are a scapula and a coracoid, still in articulation, showing the glenoid surface in which the humerus inserted. The humerus itself is missing (Fig. S5B).

MGP-PD 26856

This catalogue number refers to an axis (Fig. S5C) pasted in non-anatomical position with several osteoderms (Fig. S5C,D). The axis is at least five centimetres long. The anterior crest is assumed to be horizontal, even if it is possible that it is broken. Next to the posterior neural margin it has been pasted an extraneous bone. The posterior part of the vertebral body was broken off and the resulting pieces were glued together in non-anatomical position. The left lateral portion of the neural arch is medially compressed. The ventral region is damaged and the hypapophysis is not visible.

MGP-PD 26858 (continuation)

Posterior to the cranium of this specimen described in the skull section, in the ventral part of the specimen there is also the proximal portion of a humerus, whose deltopectoral crest is partially preserved. The concave proximal edge of the deltopectoral crest is not evident, but it emerges abruptly from the proximal end of the humerus (character 27: 1). There is also a flat bone, probably a coracoid, and another unidentified skeletal element.

MGP-PD 31997

This catalogue number refers to a fragmentary first sacral vertebra (Fig. S5E). The neural spine is missing. Part of the left transverse process is present, but it is deformed, with a sliding plane between the capitulum and the tuberculum, so that it is not possible to state if the capitulum projects anteriorly of tuberculum or if they are nearly in the same plane (character 22). It seems that the capitulum projects anteriorly of the tuberculum, but it seems to be a taphonomic effect. The right transverse process, conversely, is broken off.

NMB-Bc.6 (Basel)

NMB-Bc.6 is represented by a complete, depressed skull and several postcranial fragments of a single individual (Fig. 1). All the parts of the specimen were extracted from the lignite slab that formerly hosted them, 3D prepared and then treated against pyrite disease. In order to maintain them in the original spatial association, the remains were laid down on a resin support that mimics the original lignite slab. Besides the large individual to which most of the fragments probably belong, there are some fragments surely representing another, much smaller, individual: part of a quadrate, some disarticulated bones, comprehending a scapula and a small vertebra (A in Fig. 1).

Moreover, in the posterior part of the large individual, there is a fragment with small teeth, most likely belonging to another small individual (therefore a third one), as they are the typical conical crocodile teeth (B in Fig. 1). Minor shearing affects the skull, whose rostrum is cut by a transverse fracture. In dorsal view, the suture pattern is difficult to discern, but can be assessed in some portions of the skull (Fig. 3). The skull seems to be quite asymmetrical, probably due to taphonomic deformation. In ventral view, the mandibular rami are visible (Fig. S6), but the palatal structure is only slightly perceivable, as the ventral surface is much worse preserved than the dorsal one.

Skull -The right side of the cranium is broken at the level of the contact between lacrimal and nasal. The premaxilla bears short dorsal processes, not extending beyond the third maxillary alveolus (character 90:0), visible even considering the fracture that crosses this area.

On the left side, the lacrimal tapers relatively far anteriorly at about the level of the sixth maxillary alveolus and therefore extensively contacts the posterolateral margin of the nasal. Whether or not a process of the maxilla extends between the lacrimal and the nasal cannot be stated, because the suture is not evident enough in that area. The prefrontal does not extend as far as the lacrimal, but is quite elongate. The frontal separates the posterior tip of the two nasals.

Given the quite elongate rostrum, the orbital region does not extend into the anterior half of the skull and is characterized by a narrow interorbital width and by small orbits. The anterior projection of the frontal is narrow. The interorbital region is marked by a well-delineated preorbital ridge passing through the frontal and following the anteromedial margin of the orbits on the prefrontal and lacrimal. The anterior-most margin of the orbits is formed by the lacrimal and is notched.

The compression of the skull table has mostly a vertical component, but with a slight anterolateral direction, so that the exoccipital faces dorsally. The supratemporal fenestrae are circular. As in the Padua specimens, the frontoparietal suture extends to the supratemporal fenestrae, preventing the postorbital from contacting the parietal on the skull table. The space between the supratemporal fenestrae is wide. The supraoccipital clearly participates in the dorsal surface of the skull table, but does not prevent the parietal from reaching the posterior margin of the table. The squamosal prongs seem to project posteriorly, but this is actually due to the forward compression of the skull table, which permits observation of the exoccipital surface and the squamosal prongs descending along this bone. Actually, the squamosal prongs are short and do not project far posteriorly nor laterally.

On the medial wall of the right supratemporal fenestra, two foramina are clearly visible. The suture organisation around the lower temporal fenestra is best seen on the left side. This temporal fenestra seems very narrow and elongate but this may be an artefact of compression. The quadratojugal forms the posterior corner of this fenestra. The quadratojugal spine cannot be observed, and the postorbital bar is barely visible. The quadrate branches do not project extensively beyond the level of the skull table. The small medial quadrate hemicondyle bears the notch for the foramen aëreum on its dorsal surface, as evidenced from the right quadrate. The exoccipital is largely exposed, even if deformed.

The mandible is deformed and fractured in various locations, to the point that no sutures can be identified. The right articular is visible in dorsal view and reveals the presence of the foramen aëreum, which is laterally shifted, positioned in line with the corresponding foramen of the quadrate, and set in from the margin of the retroarticular process (character 70:1). The retroarticular process is deeply concave and its tip projects posterodorsally. The right external mandibular fenestra is not particularly wide, thus the foramen intermandibularis caudalis, even if not directly identified, can be reconstructed to have not been visible through the fenestra (character 63:1).

The basioccipital is visible (Fig. S6C), bearing a prominent medial crest, but because of the deformation it is not possible to identify its orientation (character 168).

Dentition and Occlusion-The maxilla has a pair of caniniform teeth on the left side corresponding to the fourth and fifth teeth. There is an overbite of the premaxillary and maxillary bones over the dentary. Only one large dentary tooth is visible at the level of the left premaxillary-maxillary notch.

Postcranial Skeleton-Limited information can be gained from the postcranial elements. They were partly dissociated before burial of the animals as testified by the incompleteness of the Basel specimen, which lacks the posterior trunk region, the limbs, and a big portion of the cervical area (Fig. 1). The ribs are in some cases present, but disarticulated and broken.

Posterior to the exoccipital of the skull, the first three -and part of the fourth -cervical vertebrae are still in articulation, even if rotated and visible in left lateral view (Fig. 3C). The part of the atlas which is most visible is the right neural arch, while the left neural arch and the intercentrum are just perceivable by some evident parts surrounding the occipital condyle. The axis has a prominent neural spine, which is broken in its apical part and therefore the presence of a crest is equivocal (character 12). The hypapophysis of the third vertebra is not visible, but there is a break between its parapophysis and the parapophysis of the axis that could be the evidence of a structure, interpretable as the lost hypapophysis (character 18:0).

The ribs are not visible in the dorsal part of the specimen. The situation is different in its ventral part, where the neural spine of the axis is covered by two (or three: see Fig. S6C) ribs. Based on its shape, one of them is reconstructed to be one of the atlantal ribs -whose bad preservation prevents the identification of diagnostic characters -and the other one, based on its shape and on its position, one of the axis' ribs, which seems to be still in anatomical connection with the odontoid process of the axis. Another rib is present under the left part of the skull, posteriorly to the left ectopterygoid, and partially contacting it.

In the preserved trunk portion, neural arches are here visible and indicate the midline of the trunk.

There are at least four rows of dorsal keeled osteoderms. Among these, in the right part of the trunk, one row composed of three rectangular osteoderms seems to be complete, because there is a small osteoderm which is visible in both ventral and dorsal view, in the same position it should have had during the life of the individual. This osteoderm is likely a lateral osteoderm. For this reason, the osteoderms are supposed to have been three per side (Fig. 7A-B; character 40:1). The anterior margin of at least one osteoderm, the only one whose anterior part is not covered by other osteoderms, shows an anterior process (character 43:0; Fig. 7C). Each series of osteoderms overlaps the next series located posterior to it. On the contrary, the ventral osteoderms do not overlap each other.

A single sacral vertebra is present as an isolated fragment between the skull region and the thoracic region. Because of its position it seems unlikely that this vertebra belongs to the same large individual, and it seems more probable that it belongs to another, maybe smaller, individual. The sacral vertebra is the first one because the anterior part of its centrum, recognizable because of the position of the transverse process, is concave. Thanks to this information, all the vertebrae can be considered as procelous (character 21:1).

The scapula, most likely belonging to the same small individual of the vertebra, is the only limb girdle bone clearly identified, and its blade flares dorsally (character 23:0).

MLR -no number

The La Rochelle specimen is located on a lignite slab, somehow similar to the Basel one, but it has not been prepared in 3D, being still embedded in the original matrix. It bears a skull and disarticulated and fragmented portion of the postcranial skeleton.

Skull -The skull is visible in dorsal view and is dorsoventrally compressed. The La Rochelle skull is more affected by shearing in the right anterolateral direction than the Basel one, obscuring the right mandibular ramus. The suture pattern is difficult to discern, but can be assessed in some portions of the skull. The skull is relatively broad, presenting wide premaxillae, a curved maxillary contour at the level of the largest teeth and diminutive orbits. However, the rostrum is quite elongate, the interorbital space is relatively narrow and the skull table is not expanded laterally and does not project posteriorly.

The anterior region of the rostrum is massive with an almost straight anterior margin of the premaxillae. The external nares are nearly rectangular, being slightly longer than wide. The anterior region of the rim of the nares is flat and continuous with the external margin of the bone. The nasals are excluded from the posterior margin of the nares by a thick expansion of the premaxilla at the level of the premaxillary-maxillary notch. The antorbital region is obscured, and suture organization is uncertain. The skull table has been mediolaterally deformed, thus affecting the shape of the supratemporal fenestra. The frontoparietal suture penetrates between the supratemporal fenestrae, preventing the postorbital from contacting the parietal on the skull table. The squamosal prongs are short and do not project far posteriorly nor laterally. The suture organisation around the lower temporal fenestra is best seen on the left side. The lower temporal fenestra seems very narrow and elongate, but this may be an artefact of compression. The quadratojugal forms the posterior corner of this fenestra. The postorbital bar is partially preserved. The small medial quadrate hemicondyle bears the notch for the foramen aëreum on its dorsal surface, as evidenced from the right quadrate.

The position of various sutures in the mandible is difficult to assess due to preservation. A long crack runs in the posterior portion of the mandible, passing through the external mandibular fenestra. A suture departs from the posterior level of the fenestra and continues to the tip of the retroarticular process. This suture separates the surangular from the angular. The articular is visible in dorsal view and reveals the presence of the foramen aëreum, which is laterally shifted and positioned in line with the corresponding foramen of the quadrate. The retroarticular process is deeply concave and its tip projects posterodorsally.

Dentition and occlusion-The fourth maxillary tooth is smaller than the fifth and be in the process of being replaced. Part of the anterior maxillary tooth row is visible up to the sixth tooth, which is considerably smaller than the fifth one. Only one large dentary tooth is visible at the level of the left premaxillary-maxillary notch.

Postcranial skeleton-Limited information can be gained from the postcranial elements. Only the left forelimb is still partially articulated and most of the dorsal osteoderms and the trunk vertebrae are missing. The posterior region is incomplete with disarticulated hindlimbs including two femora, partially articulated tarsal bones and some caudal vertebrae in connection.

Below we present a photographic atlas of most of the material from Monteviale housed in MGP.

NHM-UK 2789

The London specimen is a 50x50cm slab on which is a badly preserved part of a small individual, most likely a juvenile. It is visible in dorsal view, with the dorsal armor composed of six rows of keeled osteoderms. There is only one osteoderm with the anterior, smooth part is visible, but it is broken so that the interior process is not recognizable. There are also the whole hindlimbs, except for part of the autopodii, and part of the left forelimb, in particular the zeugopodium and the stylopodium. (64) Surangular-dentary suture intersects external mandibular fenestra anterior to posterodorsal corner (0) or at posterodorsal corner [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(65) Angular extends dorsally toward or beyond anterior end of foramen intermandibularis caudalis;

anterior tip acute (0) or does not extend dorsally beyond anterior end of foramen intermandibularis caudalis; anterior tip very blunt [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(66) Surangular-angular suture lingually meets articular at ventral tip (0) or dorsal to tip [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(67) Surangular continues to dorsal tip of lateral wall of glenoid fossa (0) or truncated and not continuing dorsally ( 1).

(68) Articular-surangular suture simple (0) or articular bears anterior lamina dorsal to lingual foramen [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF] or articular bears anterior lamina ventral to lingual foramen (2), or bears laminae above and below foramen (3).

(69) Lingual foramen for articular artery and alveolar nerve perforates surangular entirely (0) or perforates surangular/angular suture (1).

(70) Foramen aerum at extreme lingual margin of retroarticular process (0) or set in from margin of retroarticular process [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(71) Retroarticular process projects posteriorly (0) or projects posterodorsally [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(72) Surangular extends to posterior end of retroarticular process (0) or pinched off anterior to tip of retroarticular process [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(73) Surangular-articular suture oriented anteroposteriorly (0) or bowed strongly laterally (1) within glenoid fossa.

(74) Sulcus between articular and surangular (0) or articular flush against surangular (1).

(75) Dorsal projection of hyoid cornu flat (0) or rodlike [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(76) Dorsal projection of hyoid cornu narrow, with parallel sides (0) or flared [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(77) Lingual osmoregulatory pores small (0) or large [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(78) Tongue with (0) or without (1) keratinized surface.

(79) Teeth and alveoli of maxilla and/or dentary circular in cross-section (0), or posterior teeth laterally compressed [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], or all teeth compressed (2) (80) Maxillary and dentary teeth with smooth carinae (0) or serrated [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(81) Naris projects anterodorsally (0) or dorsally [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(82) External naris bisected by nasals (0) or nasals contact external naris, but do not bisect it (1), or nasals excluded, at least externally, from naris; nasals and premaxillae still in contact (2), or nasals and premaxillae not in contact (3).

(83) Naris circular or keyhole-shaped (0), or wider than long (1), or anteroposteriorly long and prominently teardrop-shaped (2).

(84) External naris of reproductively mature males (0) remains similar to that of females or [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF] develops bony excrescence (ghara).

(85) External naris (0) opens flush with dorsal surface of premaxillae or (1) circumscribed by thin crest.

(86) Premaxillary surface lateral to naris smooth (0) or with deep notch lateral to naris (1).

(87) Premaxilla has five teeth (0) or four teeth (1) early in post-hatching ontogeny.

(88) Incisive foramen small, less than half the greatest width of premaxillae (0), or large, more than half the greatest width of premaxillae (1), or large, and intersects premaxillary-maxillary suture (2).

(89) Incisive foramen completely situated far from premaxillary tooth row, at the level of the second or third alveolus (0), or abuts premaxillary tooth row [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], or projects between first premaxillary teeth (2).

(90) Dorsal premaxillary processes short, not extending beyond third maxillary alveolus (0) or long, extending beyond third maxillary alveolus [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(91) Dentary tooth 4 occludes in notch between premaxilla and maxilla early in ontogeny (0) or occludes in a pit between premaxilla and maxilla; no notch early in ontogeny ( 1).

(92) All dentary teeth occlude lingual to maxillary teeth (0) or occlusion pit between seventh and eight maxillary teeth; all other dentary teeth occlude lingally (1), or dentary teeth occlude in line with maxillary tooth row (2).

(93) Largest maxillary alveolus is 3 (0), 5 (1), 4 (2), 4 and 5 are same size (3), 6 (4), or maxillary teeth homodont (5), or maxillary alveoli gradually increase in diameter posteriorly toward penultimate alveolus (6).

(94) Maxillary tooth row curved medially or linear (0) or curves laterally broadly (1) posterior to first six maxillary alveoli.

(95) Dorsal surface of rostrum curves smoothly (0) or bears medial dorsal boss [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(96) Canthi rostralii absent or very modest (0) or very prominent (1) at maturity.

(97) Preorbital ridges absent or very modest (0) or very prominent (1) at maturity.

(98) Vomer entirely obscured by premaxilla and maxilla (0) or exposed on palate at premaxillarymaxillary suture (1).

(99) Vomer entirely obscured by maxillae and palatines (0) or exposed on palate between palatines (1).

(100) Surface of maxilla within narial canal imperforate (0) or with a linear array of pits ( 1).

(101) Medial jugal foramen small (0) or very large [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(102) Maxillary foramen for palatine ramus of cranial nerve V small or not present (0) or very large [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(103) Ectopterygoid abuts maxillary tooth row (0) or maxilla broadly separates ectopterygoid from maxillary tooth row ( 1).

(104) Maxilla terminates in palatal view anterior to lower temporal bar (0) or comprises part of the lower temporal bar ( 1).

(105) Penultimate maxillary alveolus less than (0) or more than (1) twice the diameter of the last maxillary alveolus.

(106) Prefrontal dorsal surface smooth adjacent to orbital rim (0) or bearing discrete knoblike processes ( 1).

(107) Dorsal half of prefrontal pillar narrow (0) or expanded anteroposteriorly [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(108) Medial process of prefrontal pillar expanded dorsoventrally (0) or anteroposteriorly [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(109) Prefrontal pillar solid (0) or with large pneumatic recess (1).

(110) Medial process of prefrontal pillar wide (0) or constricted (1) at base.

(111) Maxilla has linear medial margin adjacent to suborbital fenestra (0) or bears broad shelf extending into fenestra, making lateral margin concave (1).

(112) Anterior face of palatine process rounded or pointed anteriorly (0) or notched anteriorly (1).

(113) Anterior ectopterygoid process tapers to a point (0) or forked [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(114) Palatine process extends (0) or does not extend (1) significantly beyond anterior end of suborbital fenestra.

(115) Palatine process generally broad anteriorly (0) or in form of thin wedge [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(116) Lateral edges of palatines smooth anteriorly (0) or with lateral process projecting from palatines into suborbital fenestrae [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(117) Palatine-pterygoid suture nearly at (0) or far from (1) posterior angle of suborbital fenestra.

(118) Pterygoid ramus of ectopterygoid straight, posterolateral margin of suborbital fenestra linear (0) or ramus bowed, posterolateral margin of fenestra concave (1) (rephrased from original).

(119) Lateral edges of palatines parallel posteriorly (0) or flare posteriorly, producing shelf ( 1).

(120) Anterior border of the choana is comprised of the palatines (0) or choana entirely surrounded by pterygoids ( 1).

(121) Choana projects posteroventrally (0) or anteroventrally (1) at maturity.

(122) Pterygoid surface lateral and anterior to internal choana flush with choanal margin (0), or pushed inward anterolateral to choanal aperture [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], or pushed inward around choana to form neck surrounding aperture (2), or everted from flat surface to form neck surrounding aperture (3).

(123) Posterior rim of internal choana not deeply notched (0) or deeply notched [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(124) Internal choana not septate (0), or with septum that remains recessed within choana (1), or with septum that projects out of choana (2).

(125) Ectopterygoid-pterygoid flexure disappears during ontogeny (0) or remains throughout ontogeny [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(126) Ectopterygoid extends (0) or does not extend [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF] to posterior tip of lateral pterygoid flange at maturity.

(127) Lacrimal makes broad contact with nasal; no posterior process of maxilla (0), or maxilla with posterior process within lacrimal (1), or maxilla with posterior process between lacrimal and prefrontal (2).

(128) Prefrontals separated by frontals and nasals (0) or prefrontals meet medially [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(129) Lacrimal longer than prefrontal (0), or prefrontal longer than lacrimal (1), or lacrimal and prefrontal both elongate and nearly the same length (2).

(130) Ectopterygoid extends along medial face of postorbital bar (0) or stops abruptly ventral to postorbital bar [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(131) Postorbital bar massive (0) or slender [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(132) Postorbital bar bears process that is prominent, dorsoventrally broad, and divisible into two spines (0) or bears process that is short and generally not prominent [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(133) Ventral margin of postorbital bar flush with lateral jugal surface (0) or inset from lateral jugal surface ( 1).

(134) Postorbital bar continuous with anterolateral edge of skull table (0) or inset [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(135) Margin of orbit flush with skull surface (0), or dorsal edges of orbits upturned [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], or orbital margin telescoped (2).

(136) Ventral margin of orbit circular (0) or with prominent notch [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(137) Palpebral forms from single ossification (0) or from multiple ossifications [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(138) Quadratojugal spine prominent at maturity (0) or greatly reduced or absent at maturity [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(139) Quadratojugal spine low, near posterior angle of infratemporal fenestra (0) or high, between posterior and superior angles of infratemporal fenestra [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(140) Quadratojugal forms posterior angle of infratemporal fenestra (0), or jugal forms posterior angle of infratemporal fenestra (1), or quadratojugal-jugal suture lies at posterior angle of infratemporal fenestra (2).

(141) Postorbital neither contacts quadrate nor quadratojugal medially (0), or contacts quadratojugal, but not quadrate, medially [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], or contacts quadrate and quadratojugal at dorsal angle of infratemporal fenestra (2), or contacts quadratojugal with significant descending process (3).

(142) Quadratojugal bears long anterior process along lower temporal bar (0) or bears modest process, or none at all, along lower temporal bar [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(143) Quadratojugal extends to superior angle of infratemporal fenestra (0) or does not extend to superior angle of infratemporal fenestra; quadrate participates in fenestra ( 1).

(144) Postorbital-squamosal suture oriented ventrally (0) or passes medially (1) ventral to skull table.

(145) Dorsal and ventral rims of squamosal groove for external ear valve musculature parallel (0) or squamosal groove flares anteriorly [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(146) Squamosal-quadrate suture extends dorsally along posterior margin of external auditory meatus (0) or extends only to posteroventral corner of external auditory meatus [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(147) Posterior margin of otic aperture smooth (0) or bowed [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(148) Frontoparietal suture deeply within supratemporal fenestra; frontal prevents broad contact between postorbital and parietal (0), or suture makes modest entry into supratemporal fenestra at maturity; postorbital and parietal in broad contact [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], or suture on skull table entirely (2).

(149) Frontoparietal suture concavoconvex (0) or linear (1) between supratemporal fenestrae.

(150) Supratemporal fenestra with fossa; dermal bones of skull roof do not overhang rim at maturity (0), or dermal bones of skull roof overhang rim of supratemporal fenestra near maturity (1), or supratemporal fenestra closes during ontogeny (2).

(151) Shallow fossa at anteromedial corner of supratemporal fenestra (0) or no such fossa; anteromedial corner of supratemporal fenestra smooth [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(152) Medial parietal wall of supratemporal fenestra imperforate (0) or bearing foramina [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(153) Parietal and squamosal widely separated by quadrate on posterior wall of supratemporal fenestra (0), or parietal and squamosal approach each other on posterior wall of supratemporal fenestra without actually making contact [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], or parietal and squamosal meet along posterior wall of supratemporal fenestra (2).

(154) Skull table surface slopes ventrally from sagittal axis (0) or planar (1) at maturity.

(155) Posterolateral margin of squamosal horizontal or nearly so (0) or upturned to form a discrete horn [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(156) Mature skull table with broad curvature; short posterolateral squamosal rami along paroccipital process (0) or with nearly horizontal sides; significant posterolateral squamosal rami along paroccipital process [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(157) Squamosal does not extend (0) or extends [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF] ventrolaterally to lateral extent of paroccipital process.

(158) Supraoccipital exposure on dorsal skull table small (0), absent [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], large (2), or large such that parietal is excluded from posterior edge of table (3). (163) Laterosphenoid bridge comprised entirely of laterosphenoid (0) or with ascending process or palatine [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(164) Capitate process of laterosphenoid oriented laterally (0) or anteroposteriorly (1) toward midline.

(165) Parietal with recess communicating with pneumatic system (0) or solid, without recess [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(166) Significant ventral quadrate process on lateral braincase wall (0) or quadrate-pterygoid suture linear from basisphenoid exposure to trigeminal foramen [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(167) Lateral carotid foramen opens lateral (0) or dorsal ( 1) to basisphenoid at maturity.

(168) External surface of basioccipital ventral to occipital condyle oriented posteroventrally (0) or posteriorly (1) at maturity.

(169) Posterior pterygoid processes tall and prominent (0), or small and project posteroventrally (1), or small and project posteriorly (2).

(170) Basisphenoid thin (0) or anteroposteriorly wide (1) ventral to basioccipital.

(171) Basisphenoid not broadly exposed ventral to basioccipital at maturity; pterygoid short ventral to median eustachian opening (0) or basisphenoid exposed as broad sheet ventral to basioccipital at maturity; pterygoid tall ventral to median eustachian opening [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(172) Exoccipital with very prominent boss on paroccipital process; process lateral to cranioquadrate opening short (0) or exoccipital with small or no boss on paroccipital process; process lateral to cranioquadrate opening long [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(173) Lateral eustachian canals open dorsal (0) or lateral [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF] to medial eustachian canal.

(174) Exoccipitals terminate dorsal to basioccipital tubera (0), or send robust process ventrally and participate in basioccipital tubera [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF], or send slender process ventrally to basioccipital tubera (2).

(175) Quadrate foramen aerum on mediodorsal angle (0) or on dorsal surface (1) of quadrate.

(176) Quadrate foramen aereum is small (0), comparatively large (1), or absent (2) at maturity.

(177) Quadrate lacks (0) or bears [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF] prominent, mediolaterally thin crest on dorsal surface of ramus.

(178) Attachment scar for posterior mandibular adductor muscle on ventral surface of quadrate ramus forms modest crests (0) or prominent knob [START_REF]Ventral tubercle of proatlas more than one-half (0) or no more than one half (1) the width of the dorsal crest[END_REF].

(179) Quadrate with small, ventrally-reflected medial hemicondyle (0) or with small medial hemicondyle; dorsal notch for foramen aerum (1), or with prominent dorsal projection between hemicondyles (2), or with expanded medial hemicondyle (3).

  Abbreviations-MLR, Musée d'Histoire Naturelle de La Rochelle, France; MGP-PD, Museo di Geologia e Paleontologia dell'Università di Padova, Italy; NHM-UK, Natural History Museum of London, United Kingdon; NMB, Naturhistorisches Museum Basel, Switzerland.

  Appendix 1 for a complete description of all the specimens. The material includes the two lectotypes: MGP-PD 26814 (lectotype of Diplocynodon dalpiazi) and MGP-PD 26843 (lectotype of Asiatosuchus monsvialensis). Besides them, the material housed in Padua includes: eight skulls (MGP-PD 10170, MGP-PD 11407, MGP-PD 28164, MGP-PD 26816 and MGP-PD 26817, (skull and lower jaw of the same individual), MGP-PD 26844, MGP-PD 26845, MGP-PD 26846, MGP-PD 26858); three rostri (MGP-PD 26815, MGP-PD 26850, MGP-PD 26862); nine isolated skull fragments (MGP-PD 8648, MGP-PD 26819, MGP-PD 26835, MGP-PD 26837, MGP-PD 26838, MGP-PD 26842, MGP-PD 26957, MGP-PD 26859, MGP-PD 31998); several disarticulated teeth (MGP-PD 26839); and various postcranial elements (MGP-PD 27999-26854 (a single, fractured slab), MGP-PD 26818, MGP-PD 26820, MGP-PD 26821, MGP-PD 26822, MGP-PD 26823, MGP-PD 26824, MGP-PD 26825 -26830 (a single, fractured slab), MGP-PD 26826, MGP-PD 26827, MGP-PD 26828, MGP-PD 26829, MGP-PD 26831 -26832 -26833 -26834 (derived from the same individual), MGP-PD 26836, MGP-PD 26840, MGP-PD 26841, MGP-PD 26847, MGP-PD 26848, MGP-PD 26849, MGP-PD 26851, MGP-PD 26852-26853 (a single, fractured slab), MGP-PD 26855, MGP-PD 26856, MGP-PD 31997). Besides the numbered specimens, in the Padua museum there are several specimens without numbers: seven fragments of mandibles and maxillae, more than 40 disarticulated teeth, five slabs with poorly preserved portions of the vertebral column, five isolated vertebrae, seven slabs with fragmentary and disarticulated limbs, and several ribs and osteoderms.

FIGURE 1 .FIGURE 7 .

 17 FIGURE CAPTIONS

Figure S1 .

 S1 Figure S1. Selection of Padua skulls: MGP-PD 26843 in dorsal (A) and ventral (B) view, 26845 in

Figure S2 .

 S2 Figure S2. Left part of a rostrum (MGP-PD 26862) in lateral (A, B) and frontal (C) view. D) right

Figure S3 .

 S3 Figure S3. Postcranial elements from Padua. A) part of a dorsal vertebral column (MGP-PD 27999

Figure S5 .

 S5 Figure S5. Postcranial elements from Padua. A) scapular girdle with ribs (MGP-PD 26855). B)

Figure S6 .

 S6 Figure S6. NMB-Bc.6 skull in ventral view. Scale bar 5 cm. Ar: articular, Atr: atlantal rib, Ax:

Figure S7 .

 S7 Figure S7. Dorsal (A) and ventral (D) armour of NMB-Bc.6. Lateral osteoderm in lateral (C) and

( 159 )

 159 Anterior foramen for palatine ramus of cranial nerve VII ventrolateral (0) or ventral (1) to basisphenoid rostrum. (160) Sulcus on anterior braincase wall lateral to basisphenoid rostrum (0) or braincase wall lateral to basisphenoid rostrum smooth; no sulcus (1). (161) Basisphenoid not exposed extensively (0) or exposed extensively (1) on braincase wall anterior to trigeminal foramen. (162) Extensive exposure of prootic on external braincase wall (0) or prootic largely obscured by quadrate and laterosphenoid externally (1).

TABLE 1 .

 1 Strontium isotope ratios (87/86) of selected lignites sampled in the embedding matrix of crocodilian skeletons housed in various institutions.

	Provenance	Sample	Mean 87 Sr/ 86 Sr 2SD
	unknown	NHM Basle	0,709	0,001
	unknown	La Rochelle	0,714	0,003
	unknown	NHMUK PRV 2789	0,710	0,002
	Monteviale	MGP26855	0,709	0,002
	Monteviale	MGP 26836	0,710	0,002
	Purga di Bolca	1	0,734	0,008
	Purga di Bolca	2	0,731	0,007

ACKNOWLEDGMENTS LM thanks A. Borrani for the help during the phylogenetic analysis with TNT, S. Maidment for access to the NHMUK collections, and P. Mannion and C. Nicholl for assistance. LM visited NHMUK thanks to an Erasmus Traineeship at the Imperial College of London (under the supervision of P. Mannion). JEM thanks E. Buffetaut and J-M. Mazin for reading an early version; JEM also thanks P. Telouk at LGLTPE for his help in setting up the laser ablation facilities. S. Salisbury provided comments on an earlier draft of this manuscript. Michael D'Emic, Daniela Schwarz and an anonymous reviewer greatly enhanced the quality of a former version of this work through constructive comments. JEM thanks the curators who provided lignite samples for analysis: L. Costeur (Basel), J-F. Heil (La Rochelle), R. Vullo (La Rochelle), M. Fornasiero (Padua), R. Zorzin (Verona) and L. Steel (NHM-UK, London).