Iván Ramírez-Pedraza
email: ramirezpedrazaivan@gmail.com

Florent Rivals

Carlos Tornero

Denis Geraads

Jean Paul Raynal

David Lefèvre

Abderrahim Mohib

Palaeoecological reconstruction of Plio-Pleistocene herbivores from the Ahl al Oughlam site (Casablanca, Morocco): Insights from dental wear and stable isotopes

Keywords: North Africa, diet, habitat, stable isotopes, microwear, mesowear

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Introduction 1.2 The archaeopaleontological context during the Plio-Pleistocene in North Africa

The richness and diversity of mammalian fossil remains in the Maghreb during the Late Pliocene and Early Pleistocene [START_REF] Geraads | Plio-Pleistocene mammalian biostratigraphy of Atlantic Morocco[END_REF][START_REF] Raynal | Casablanca and the earliest occupation of North Atlantic Morocco[END_REF][START_REF] Sahnouni | The Oldowan in North Africa within a biochronological framework[END_REF][START_REF] Sahnouni | Ecological background to Plio-Pleistocene hominin occupation in North Africa: The vertebrate faunas from Aïn Boucherit, Aïn Hanech and El-Kherba, and paleosol stable-carbon-isotope studies from El-Kherba, Algeria[END_REF][START_REF] Van Der Made | The North African earliest Pleistocene faunal sequence: from biostratigraphy to biochronology[END_REF] provides evidence that the Sahara Desert was not always a natural barrier for mammals in the past. The region experienced multiple green and humid phases, known as Green Sahara periods (GSPs), over millions of years, including the Plio-Pleistocene. During these events, the present desert area consisted of river basins and extensive lakes [START_REF] Van Zinderen Barker | A Late-Glacial and Post-Glacial Climatic Correlation between East Africa and Europe[END_REF][START_REF] Larrasoaña | Three million years of monsoon variability over the northern Sahara[END_REF][START_REF] Larrasoaña | Dynamics of Green Sahara Periods and their role in hominin evolution[END_REF][START_REF] Castañeda | Wet phases in the Sahara/Sahel region and human migration patterns in North Africa[END_REF][START_REF] Grant | A 3 million year index for North African humidity/aridity and the implication of potential pan-African Humid periods[END_REF][START_REF] Grant | Organic carbon burial in Mediterranean sapropels intensified during Green Sahara Periods since 3.2 Myr ago[END_REF][START_REF] Larrasoaña | A review of West African monsoon penetration during Green Sahara Periods; implications for human evolution and dispersals over the last three million years[END_REF]. These environmental conditions would have facilitated episodes of mammalian dispersal from sub-Saharan locations to the north of Africa [START_REF] Geraads | Biogeographic relationships of Pliocene and Pleistocene Northwestern African mammals[END_REF][START_REF] Zouhri | Mammifères du Néogène continental du Maroc: Faunes, biochronologie et paléobiogéographie[END_REF][START_REF] Van Der Made | The North African earliest Pleistocene faunal sequence: from biostratigraphy to biochronology[END_REF].

To date, the oldest artifacts and stone tool-cut marked bones in North Africa associated with the presence of hominins have been found at the site of Aïn Boucherit (~1.9 and ~2.4 Ma) in the Beni Fouda intramontane basin in northeast Algeria [START_REF] Sahnouni | 1.9-million-and 2.4-million-year-old artifacts and stone tool-cutmarked bones from Aïn Boucherit[END_REF][START_REF] Duval | The Plio-Pleistocene sequence of Oued Boucherit (Algeria): A unique chronologically-constrained archaeological and palaeontological record in North Africa[END_REF]. In the same area, Acheulean technology has been described at the sites of Aïn Hanech and El Kherba (~1.8 Ma) [START_REF] Sahnouni | Further research at the Oldowan site of Aïn Hanech, North-eastern Algeria[END_REF][START_REF] Sahnouni | The first evidence of cut marks and usewear traces from the Plio-Pleistocene locality of El-Kherba (Aïn Hanech), Algeria: Implications for early hominin subsistence activities circa 1.8 Ma[END_REF][START_REF] Sahnouni | Mise en évidence d'un changement climatique dans le site pléistocène inférieur d'El Kherba (Algérie), et son possible impact sur les activités des hominidés, il y a 1,7[END_REF][START_REF] Parés | Early human settlements in Northern Africa: paleomagnetic evidence from the Aïn Hanech Formation (northeastern Algeria)[END_REF][START_REF] Duval | The Plio-Pleistocene sequence of Oued Boucherit (Algeria): A unique chronologically-constrained archaeological and palaeontological record in North Africa[END_REF][START_REF] Duval | On the age of Aïn Hanech Oldowan locality (Algeria): First numerical dating results[END_REF][START_REF] Van Der Made | The North African earliest Pleistocene faunal sequence: from biostratigraphy to biochronology[END_REF]. In the Constantine Basin (Algeria), biochronologically close to Aïn Hanech, is the littleknown site of Mansourah, with abundant faunal remains and bifacial artifacts associated with the Oldowan industry [START_REF] Thomas | Recherches stratigraphiques et paléontologiques sur quelques formations d'eau douce de l'Algérie[END_REF][START_REF] Thomas | Notes additionelles sur les vertébrés fossiles de la province de Constantine[END_REF][START_REF] Chaid-Saoudi | The fauna and associated artefacts from the Lower Pleistocene site of Mansourah (Constantine, Algeria)[END_REF][START_REF] Sahnouni | The Oldowan in North Africa within a biochronological framework[END_REF] and the palaeontological site of Aïn Jourdel (~2.5 Ma) [START_REF] Thomas | Recherches stratigraphiques et paléontologiques sur quelques formations d'eau douce de l'Algérie[END_REF][START_REF] Thomas | Notes additionelles sur les vertébrés fossiles de la province de Constantine[END_REF][START_REF] Duval | The Plio-Pleistocene sequence of Oued Boucherit (Algeria): A unique chronologically-constrained archaeological and palaeontological record in North Africa[END_REF]. The oldest human remains have been found in western Algeria at Tighennif, also called Ternifine, ~1 Ma [START_REF] Arambourg | Le Gisement de Ternifine[END_REF][START_REF] Geraads | The Pleistocene hominid site of Ternifine, Algeria: New results on the environment, age, and human industries[END_REF][START_REF] Bocherens | Isotopic biogeochemistry ( 13 C, 18 O) of mammalian enamel from african pleistocene hominid sites[END_REF][START_REF] Geraads | Pleistocene Carnivora (Mammalia) from Tighennif (Ternifine), Algeria[END_REF][START_REF] Van Der Made | The North African earliest Pleistocene faunal sequence: from biostratigraphy to biochronology[END_REF]. In western Morocco, near Casablanca, the earliest archaeological sites date back to the Early and Middle Pleistocene [START_REF] Raynal | The earliest occupation of North-Africa: the Moroccan perspective[END_REF][START_REF] Raynal | Casablanca and the earliest occupation of North Atlantic Morocco[END_REF][START_REF] Raynal | The western quest, First and Second Regional Acheuleans at Thomas-Oulad Hamida Quarries (Casablanca, Morocco)[END_REF][START_REF] Mohib | Forty years of research at Casablanca (Morocco): New insights in the Early/Middle Pleistocene archaeology and geology[END_REF][START_REF] Gallotti | The African Acheulean: a view from the western Maghreb. L'Acheuléen africain vu de l'extrême Maghreb[END_REF]. Up to now, the oldest site with human presence corresponds to unit L of Thomas Quarry I and its abundant ancient Acheulean lithic tools (~1.3 Ma) (Raynal and Texier, 1989;[START_REF] Gallotti | Dedicated core-on-anvil production of bladelet-like flakes in the Acheulean at Thomas Quarry I -L1 (Casablanca, Morocco)[END_REF][START_REF] Gallotti | First high resolution chronostratigraphy for the early North African Acheulean at Casablanca (Morocco)[END_REF][START_REF] Gallotti | Early North African Acheulean technoeconomic systems at Thomas Quarry I -L1 (Casablanca, Morocco)[END_REF]. The former Thomas III Quarry, in which Homo remains were found [START_REF] Ennouchi | New discovery of an Archanthropian in Morocco[END_REF][START_REF] Geraads | La faune et l'industrie des sites à Homo erectus des carrières Thomas (Maroc). Précisions sur l'âge de ces Hominidés[END_REF], 2022a and b;[START_REF] Raynal | Lettre de Casablanca où fut trouvé Homo darelbeidae.A letter from Casablanca where Homo darelbeidae was found[END_REF] was renamed Oulad Hamida 1 Quarry when the Grotte des Rhinocéros (~0.7 Ma) was discovered and delivered a single Homo remain associated with stone tools and fauna [START_REF] Raynal | La grotte des Rhinocéros (Carrière Oulad Hamida 1, anciennement Thomas III, Casablanca), nouveau site acheuléen du Maroc atlantique[END_REF](Raynal et al., , 2022b;;[START_REF] Rhodes | New age estimates for the Palaeolithic assemblages and Pleistocene succession of Casablanca, Morocco[END_REF][START_REF] Daujeard | Carcass acquisition and consumption by carnivores and hominins in Middle Pleistocene sites of Casablanca (Morocco)[END_REF][START_REF] Daujeard | Earliest African evidence of carcass processing and consumption in cave at 700 ka, Casablanca, Morocco[END_REF][START_REF] Raynal | Préhistoire de Casablanca. 1 -La Grotte des Rhinocéros (fouilles 1991 et[END_REF][START_REF] Gallotti | The African Acheulean: a view from the western Maghreb. L'Acheuléen africain vu de l'extrême Maghreb[END_REF]. In Thomas Quarry I, above level L, Hominid Cave (~0.5/0.7 Ma) is also located, where early Homo remains on the Atlantic shore were discovered [START_REF] Ennouchi | New discovery of an Archanthropian in Morocco[END_REF][START_REF] Geraads | La faune et l'industrie des sites à Homo erectus des carrières Thomas (Maroc). Précisions sur l'âge de ces Hominidés[END_REF]Geraads et al., , 2022a;;[START_REF] Raynal | Hominid Cave at Thomas Quarry I (Casablanca, Morocco): Recent findings and their context[END_REF]Raynal et al., , 2022a;;[START_REF] Daujeard | Pleistocene hominins as a resource for carnivores: A c. 500,000-year-old human femur bearing tooth-marks in North Africa (Thomas Quarry I, Morocco)[END_REF][START_REF] Daujeard | Earliest African evidence of carcass processing and consumption in cave at 700 ka, Casablanca, Morocco[END_REF][START_REF] Raynal | Lettre de Casablanca où fut trouvé Homo darelbeidae.A letter from Casablanca where Homo darelbeidae was found[END_REF].

On the outskirts of Casablanca sits the site of Ahl al Oughlam (AaO), the richest Neogene faunal site in North Africa dated to ~2.5 Ma (Raynal et al., 1990;[START_REF] Geraads | The late Pliocene locality of Ahl al Oughlam, Morocco: Vertebrate fauna and interpretation[END_REF][START_REF] Geraads | Mammalian faunas from the Pliocene and Pleistocene of Casablanca (Morocco)[END_REF]Geraads et al., , 2022b) ) and whose ecological context is investigated in this work.

In eastern Morocco, close to the Algerian border in the Aïn Beni Mathar-Guefaït area (Jerada province), several sites have been discovered and excavated since 2006: the Early Pleistocene sites of Aïn Tabouda, Gara Soultana and Charchara 1 with Mode 1 lithic tools, and the Middle Pleistocene site of Oued Rabt with Mode 2 lithic tools [START_REF] Sala-Ramos | Pleistocene and Holocene peopling of Jerada province, eastern Morocco: introducing a research project. Le peuplement humain pendant le Pléistocène et l'Holocène dans la province de Jerada[END_REF]. The oldest site, although palaeontological, is Guefaït. This one is biochronologically located at the Plio-Pleistocene boundary (~3-2.5 Ma; [START_REF] Duval | On the age of Aïn Hanech Oldowan locality (Algeria): First numerical dating results[END_REF], contemporaneous with Ahl al Oughlam, and contains a large diversity of taxa in its fossiliferous levels [START_REF] Sala-Ramos | Pleistocene and Holocene peopling of Jerada province, eastern Morocco: introducing a research project. Le peuplement humain pendant le Pléistocène et l'Holocène dans la province de Jerada[END_REF], 2022;[START_REF] Aouraghe | Nouvelles données sur le site du Pliocène Final/Pléistocène Inférieur de Guefaït 4: Mission 2019[END_REF]Piñero et al., 2019;[START_REF] Alba | New macaque fossil remains from Morocco[END_REF][START_REF] Madurell-Malapeira | First small-sized Dinofelis: Evidence from the Plio-Pleistocene of North Africa[END_REF][START_REF] Ramírez-Pedraza | Multiproxy approach to reconstruct fossil primate feeding behavior: Case study for macaque from the Plio-Pleistocene site Guefaït-4.2 (eastern Morocco)[END_REF].

Work based on palaeoecological reconstructions are underrepresented in North Africa, despite the abundance of archaeopalaeontological sites found from the Late Pliocene to the Early Pleistocene in this territory. In Morocco, the studies published to date are focused on the palaeoecology of the Plio-Pleistocene primates of Ahl al Oughlam (Theropithecus; [START_REF] Fannin | Carbon and strontium isotope ratios shed new light on the paleobiology and collapse of Theropithecus, a primate experiment in graminivory[END_REF] and Guefaït-4.2 (Macaca;[START_REF] Ramírez-Pedraza | Multiproxy approach to reconstruct fossil primate feeding behavior: Case study for macaque from the Plio-Pleistocene site Guefaït-4.2 (eastern Morocco)[END_REF]. In Algeria, there are more extensive studies available, such as the analysis of carbon and oxygen stable isotopes in herbivores from Tighennif (~1 Ma) [START_REF] Bocherens | Isotopic biogeochemistry ( 13 C, 18 O) of mammalian enamel from african pleistocene hominid sites[END_REF][START_REF] Fannin | Carbon and strontium isotope ratios shed new light on the paleobiology and collapse of Theropithecus, a primate experiment in graminivory[END_REF], and the research based on stable isotopes of pedogenic carbonates from El Kherba (~1.8 Ma) [START_REF] Sahnouni | Ecological background to Plio-Pleistocene hominin occupation in North Africa: The vertebrate faunas from Aïn Boucherit, Aïn Hanech and El-Kherba, and paleosol stable-carbon-isotope studies from El-Kherba, Algeria[END_REF]. However, there still remains a knowledge gap in this area regarding the reconstruction of habitats at the Plio-Pleistocene boundary. This contrasts with the numerous and comprehensive studies carried out in eastern [START_REF] Kingston | Isotopic dietary reconstructions of Pliocene herbivores at Laetoli: Implications for early hominin paleoecology[END_REF][START_REF] Ségalen | Timing of C 4 grass expansion across sub-Saharan Africa[END_REF][START_REF] Levin | Herbivore enamel carbon isotopic composition and the environmental context of Ardipithecus at Gona, Ethiopia[END_REF][START_REF] Bedaso | Dietary and paleoenvironmental reconstruction using stable isotopes of herbivore tooth enamel from middle Pliocene Dikika, Ethiopia: Implication for Australopithecus afarensis habitat and food resources[END_REF][START_REF] Cerling | Dietary changes of large herbivores in the Turkana Basin, Kenya from 4 to 1 Ma[END_REF][START_REF] Robinson | Late Pliocene environmental change during the transition from Australopithecus to Homo[END_REF][START_REF] Robinson | Intrataxonomic trends in herbivore enamel δ 13 C are decoupled from ecosystem woody cover[END_REF][START_REF] Lüdecke | Dietary versatility of Early Pleistocene hominins[END_REF]Mercader et al., 2021), southern (Lee-Thorp and[START_REF] Lee-Thorp | Opportunities and constraints for reconstructing palaeoenvironments from stable light isotope ratios in fossils[END_REF][START_REF] Lee-Thorp | Tracking changing environments using stable carbon isotopes in fossil tooth enamel: an example from the South African hominin sites[END_REF], 2010;[START_REF] Ségalen | Timing of C 4 grass expansion across sub-Saharan Africa[END_REF][START_REF] Lehmann | Stable isotopic composition of fossil mammal teeth and environmental change in southwestern South Africa during the Pliocene and Pleistocene[END_REF] and central Africa [START_REF] Zazzo | Herbivore paleodiet and paleoenvironmental changes in Chad during the Pliocene using stable isotope ratios of tooth enamel carbonate[END_REF][START_REF] Ségalen | Timing of C 4 grass expansion across sub-Saharan Africa[END_REF][START_REF] Lee-Thorp | Isotopic evidence for an early shift to C 4 resources by Pliocene hominins in Chad[END_REF] focused on the ecological contexts of Plio-Pleistocene hominins and large herbivores.

The distribution of C 3 -C 4 plants in North Africa

One of the commonly used methods for reconstructing past environments has been the analysis of stable carbon isotope ratios ( 13 C/ 12 C) in dental enamel bioapatite. This biogenic material is particularly useful due to its resistance to diagenetic processes, preserving the original isotopic signal [START_REF] Wang | A model of fossil tooth and bone diagenesis: implications for paleodiet reconstruction from stable isotopes[END_REF]. The carbon isotope ratios are primarily influenced by the differential fractionation between the two photosynthetic pathways (C 3 and C 4 ) used by plants consumed by animals, and it is associated with specific types of landscapes or environmental conditions. The proportion of C 3 or C 4 plants is not distributed homogeneously throughout Africa, varying both geographically and chronologically. Global C 4 ecosystem expansion around 8-10 million years ago, due to the decrease of atmospheric CO 2 , higher temperatures and increasing water-stress represents a significant change in the landscape that led to the replacement of C 3 grasses by C 4 grasses in existing open and dry environments in low-to mid-latitude and altitude regions [START_REF] Ehleringer | Climate change and the evolution of C 4 photosynthesis[END_REF][START_REF] Cerling | Development of grasslands and savannas in East Africa during the Neogene[END_REF][START_REF] Cerling | Global vegetation change through the Miocene/Pliocene boundary[END_REF][START_REF] Edwards | The origins of C 4 grasslands: Integrating evolutionary and ecosystem science[END_REF][START_REF] Polissar | Synchronous rise of African C 4 ecosystems 10 million years ago in the absence of aridification[END_REF]. During the Plio-Pleistocene, eastern, southern and central Africa were dominated by C 4 grassland [START_REF] Zazzo | Herbivore paleodiet and paleoenvironmental changes in Chad during the Pliocene using stable isotope ratios of tooth enamel carbonate[END_REF][START_REF] Ségalen | Timing of C 4 grass expansion across sub-Saharan Africa[END_REF][START_REF] Strömberg | Evolution of grasses and grassland ecosystems[END_REF], relegating C 3 grasses to altitudes above 2000 meters and in the forest understory [START_REF] Tieszen | The distribution of C 3 and C 4 grasses and carbon isotope discrimination along an altitudinal and moisture gradient in Kenya[END_REF][START_REF] Young | Local distribution of C 3 and C 4 grasses in sites of overlap on Mount Kenya[END_REF][START_REF] Balasse | Distinguishing sheep and goats using dental morphology and stable carbon isotopes in C 4 grassland environments[END_REF]. The ecological context of these areas, characterized by the high abundance of C 4 grasses, especially in Eastern Africa, has allowed the application of the C 4 -grazers and C 3 -browsers classification, which is widely used in studies analyzing the diet of mammals based on the analysis of tooth enamel δ 13 C values (Vogel, 1978;[START_REF] Zazzo | Herbivore paleodiet and paleoenvironmental changes in Chad during the Pliocene using stable isotope ratios of tooth enamel carbonate[END_REF]Sponheimer and Lee-Thorp, 2003;[START_REF] Lee-Thorp | Opportunities and constraints for reconstructing palaeoenvironments from stable light isotope ratios in fossils[END_REF][START_REF] Levin | Herbivore enamel carbon isotopic composition and the environmental context of Ardipithecus at Gona, Ethiopia[END_REF][START_REF] Bedaso | Dietary and paleoenvironmental reconstruction using stable isotopes of herbivore tooth enamel from middle Pliocene Dikika, Ethiopia: Implication for Australopithecus afarensis habitat and food resources[END_REF][START_REF] Cerling | Dietary changes of large herbivores in the Turkana Basin, Kenya from 4 to 1 Ma[END_REF][START_REF] Uno | Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses[END_REF]. This clear distinction between C 4 -grazers and C 3 -browsers is not valid at high latitudes, as the contribution of C 4 plants is non-existent or marginal. This pattern has been observed in multiple studies conducted during the Pliocene and Early Pleistocene in Europe [START_REF] Edwards | The origins of C 4 grasslands: Integrating evolutionary and ecosystem science[END_REF][START_REF] Domingo | Late Neogene and Early Quaternary paleoenvironmental and paleoclimatic conditions in Southwestern Europe: Isotopic analyses on mammalian taxa[END_REF][START_REF] Szabó | Pliocene -Early Pleistocene continental climate and vegetation in Europe based on stable isotope compositions of mammal tooth enamel[END_REF]. The same observation applies to studies conducted in North Africa on Pleistocene and Pliocene archaeological and palaeontological sites mentioned above [START_REF] Bocherens | Isotopic biogeochemistry ( 13 C, 18 O) of mammalian enamel from african pleistocene hominid sites[END_REF][START_REF] Sahnouni | Ecological background to Plio-Pleistocene hominin occupation in North Africa: The vertebrate faunas from Aïn Boucherit, Aïn Hanech and El-Kherba, and paleosol stable-carbon-isotope studies from El-Kherba, Algeria[END_REF][START_REF] Fannin | Carbon and strontium isotope ratios shed new light on the paleobiology and collapse of Theropithecus, a primate experiment in graminivory[END_REF]. All of them, based on carbon isotope evidence, reveal a vegetation consisting of C 3 plants including all available resources such as trees, woody shrubs, bushes and grasses. This makes it challenging to discern different diets and habitats for mammals and therefore to draw a consistent ecological reconstruction with this single method.

To address this challenge, we combine three high-resolution approaches that cover different moments in the animal's life: the δ 18 O and δ 13 C values of tooth enamel bioapatite (which reflect the first years of life related to the crown formation times), tooth mesowear (which reflects the last months/years before death) and tooth occlusal microwear (which reflects the last days/weeks before death). By combining these approaches, this work aims at providing a robust ecological reconstruction of the Ahl al Oughlam (AaO) mammal communities, which will shed light on their diets, habitats, and seasonality.

Up to the present, there is no evidence of hominins at AaO. The earliest known occupation on the Atlantic coast, in western Morocco, corresponds to level TH-L at 1.3 Ma [START_REF] Gallotti | Early North African Acheulean technoeconomic systems at Thomas Quarry I -L1 (Casablanca, Morocco)[END_REF]. However, 2.5 Ma ago, hominins were widespread in East and South Africa [START_REF] Hammond | Pleistocene Hominin Fossil Record of Africa[END_REF], in Chad, at the Koro Toro site (3.5 Ma;Brunet et al., 1995), and in Northern Africa with the oldest occupation at Ain Boucherit at 2.4 Ma [START_REF] Sahnouni | 1.9-million-and 2.4-million-year-old artifacts and stone tool-cutmarked bones from Aïn Boucherit[END_REF]. The absence of hominins in AaO does not necessarily imply their absence during the Plio-Pleistocene in the area, as it is possible that they have simply not been discovered in the fossil record. Another possibility could be that the environmental conditions did not facilitate the occupation of this area. In this study, we have also compared the ecology of the taxa from AaO with the same taxa from other sites in North, South, East, and Central Africa.

Understanding the role of this territory is crucial in contributing to the debate about the first hominin dispersions and occupations, as well as highlighting the importance of North Africa in the adaptation and development of mammal behavior during the Late Pliocene and Early Pleistocene. The fossiliferous locality of Ahl al Oughlam (33°34'11"N, 07°30'44"W) is an abandoned sandstone quarry located at the southeast boundary of the city of Casablanca (Morocco), 6.5 km from the present-day Atlantic shore (Fig. 1; Raynal et al., 1990;Geraads et al., 2022b). Stratigraphically, the quarry cuts through calcarenitic intertidal, supratidal and aeolian deposits correlative to sea-level highstands associated with a platform developed about 105 m a.s.l. which belong to the Ahl al Oughlam Morphostratigrafic Unit [START_REF] Lefèvre | The plio-pleistocene formations of Casablanca and the marine quaternary chronostratigraphy of Morocco revisited[END_REF][START_REF] Lefèvre | Casablanca plio-pleistocene palaeoshorelines, chronostratigraphicand palaeogeographic framework for the ancient prehistory of the Atlantic Morocco. Les paléolittoraux plio-pléistocènes de Casablanca, cadre chronostratigraphique et paléogéographique de la Préhistoire ancienne du Maroc atlantique[END_REF]Geraads et al., 2022b), formerly included in the Messaoudian stage of Biberson's Moroccan Quaternary Chronostratigraphy (Biberson, 1961a;[START_REF] Stearns | Pliocene-Pleistocene emergence of the Moroccan Meseta[END_REF]. The site was investigated in 1953 by Biberson (Biberson, 1961a(Biberson, , 1961b)), under the name of Carrière Déprez, who reported the occurrence of some broken pebbles that he considered as representing reworked artifacts of the "archaic pebble culture" representing an initial stage of North African technological evolution. Raynal and Texier (1989) demonstrated that they are actually "geofacts" of natural origin found in marine deposits. In 1985, J.-P. Raynal and J.-P. Texier discovered abundant fossil faunal remains in karst formations and in a network of fissures and interconnected galleries between calcarenite blocks, at the foot of what was once a palaeoshoreline.

Site: Ahl al Oughlam

The fillings lack stratification. Given that the populations of the diverse rodent species within the interconnected fissures exhibit no significant distinctions in tooth measurements, they can be regarded as synchronous on a geological scale. Since absolute dating and paleomagnetic analysis are unattainable, the age of the fossiliferous fillings hinges on the identification and evolutionary stages of various taxa [START_REF] Geraads | Plio-Pleistocene mammalian biostratigraphy of Atlantic Morocco[END_REF][START_REF] Geraads | Biogeographic relationships of Pliocene and Pleistocene Northwestern African mammals[END_REF]. A biostratigraphic analysis of the mammal assemblage dates this locality to the Plio-Pleistocene boundary, indicating an approximate age of 2.5 Ma [START_REF] Geraads | Carnivores du Pliocene terminal de Ahl al Oughlam (Casablanca, Maroc)[END_REF]Geraads et al., 2022b). The genus Equus is absent, suggesting that the site is older than 2.3 Ma [START_REF] Geraads | The late Pliocene locality of Ahl al Oughlam, Morocco: Vertebrate fauna and interpretation[END_REF]. The mammalian fauna includes at least fifty-five species of both small and large mammals. A new species of Hipparion, H. pomeli, has been described subsequently from the site [START_REF] Eisenmann | Hipparion pomeli sp. nov from the late Pliocene of Ahl al Oughlam, Morocco, and a revision of the relationships of Pliocene and Pleistocene African hipparions[END_REF]. The vertebrate fauna also includes amphibians, reptiles (tortoises, crocodiles, amphisbaenids, lizards and snakes) and fishes. The most unexpected element of the mammalian fauna is a walrus, a pinniped marine mammal. No living or fossil walrus was previously known in the Eastern Atlantic, south of Belgium [START_REF] Geraads | The late Pliocene locality of Ahl al Oughlam, Morocco: Vertebrate fauna and interpretation[END_REF]. The site was formed along the oceanic seashore which explains why both marine and terrestrial forms are found among birds. A list of the identified faunal taxa is given in several publications (Raynal et al., 1990;Geraads, 1993[START_REF] Geraads | Rodents and insectivores (Mammalia) from the Late Pliocene of Ahl al Oughlam (Casablanca, Morocco)[END_REF][START_REF] Geraads | Le Sivatherium (Giraffidae, Mammalia) du Pliocène final d'Ahl al Oughlam (Casablanca, Maroc), et l'évolution du genre en Afrique[END_REF][START_REF] Geraads | Carnivores du Pliocene terminal de Ahl al Oughlam (Casablanca, Maroc)[END_REF][START_REF] Geraads | Plio-Pleistocene mammalian biostratigraphy of Atlantic Morocco[END_REF][START_REF] Geraads | New skulls of Kolpochoerus phacochoeroides (Suidae: Mammalia) from the late Pliocene of Ahl al Oughlam, Morocco. Palaeontol[END_REF][START_REF] Geraads | The late Pliocene locality of Ahl al Oughlam, Morocco: Vertebrate fauna and interpretation[END_REF][START_REF] Alemseged | Theropithecus atlanticus (Thomas, 1884) (Primates: Cercopithecidae) from the late Pliocene of Ahl al Oughlam, Casablanca, Morocco[END_REF]Geraads and Amani, 1998;[START_REF] Geraads | Proboscidea (Mammalia) du Pliocène final d'Ahl al Oughlam (Casablanca, Maroc)[END_REF][START_REF] Eisenmann | Hipparion pomeli sp. nov from the late Pliocene of Ahl al Oughlam, Morocco, and a revision of the relationships of Pliocene and Pleistocene African hipparions[END_REF][START_REF] Mourer-Chauviré | The Struthionidae and Pelagornithidae (Aves: Struthioniformes, Odontopterygiformes) from the late Pliocene of Ahl al Oughlam, Morocco[END_REF][START_REF] Geraads | Mammalian faunas from the Pliocene and Pleistocene of Casablanca (Morocco)[END_REF][START_REF] Mourer-Chauviré | The upper Pliocene avifauna of Ahl al Oughlam, Morocco. Systematics and biogeography[END_REF][START_REF] Gunnell | New late pliocene bats (Chiroptera) from Ahl al Oughlam, Morocco[END_REF][START_REF] Sen | Lagomorpha (Mammalia) from the Pliocene-Pleistocene locality of Ahl al Oughlam, Morocco. Palaeobiodiversity and Palaeoenvironments[END_REF].

Material & methods

The material sampled and analyzed is currently stored at the Institut national des Sciences de l'Archéologie et du Patrimoine (INSAP) in Rabat (Morocco). The species included in this research are the following: Sivatherium maurusium, Hipparion pomeli, Metridiochoerus phacochoeroides, Gazella sp., Alcelaphini and Anancus osiris.

Stable isotopes ( 13 C and 18 O)

In this study, we performed stable carbon ( 13 C) and oxygen ( 18 O) isotope analysis of 82 fossil fauna specimens recovered from AaO (Supplementary Table 1). Sampling has been conducted on the buccal surface of molars and premolars from adult individuals.

The tooth surfaces were cleaned with a tungsten abrasive drill bit to remove any adhering external material. Enamel powder for bulk analysis was obtained using gentle abrasion with a diamond-tipped drill.

Powdered enamel samples were chemically treated at the biomolecular laboratory at the Institut Català de Paleoecologia Humana i Evolució Social (IPHES -CERCA).

Samples weighed from 3.5 to 9.5 mg. Chemical treatment of samples was based on protocols originally proposed by [START_REF] Koch | The effects of sample treatment and diagenesis on the isotopic integrity of carbonate in biogenic hydroxylapatite[END_REF] and later modified in [START_REF] Tornero | Seasonality and season of birth in early Eneolithic sheep from Cheia (Romania): Methodological advances and implications for animal economy[END_REF]. Samples were treated for 4 h in 0.1 M acetic acid [CH3COOH] (0.1 ml solution/0.1 mg of sample), neutralized with distilled water and freeze-dried.

The 18 O and 13 C of carbonates were measured using an automated carbonate preparation device (KIEL-III) coupled with a gas-ratio mass spectrometer (Finnigan MAT 252) at the environmental isotope laboratory at the University of Arizona, US. Powdered samples were allowed to react with dehydrated phosphoric acid under a vacuum at 70°C. Accuracy and precision of the measurements were checked and calibrated using calcium carbonate international standards (NBS-19 and NBS-18). Replicate measurements of the standards during analysis had errors of ±0.1‰ for δ 18 O and ±0.08‰ for δ 13 C (1 sigma). Carbon isotope composition is reported in δ notation, where δ 13 C = [(Rsample/Rstandard) -1], R = 13 C/ 12 C and δ is expressed in per mil, ‰. Carbon and oxygen values are reported relative to PDB (Vienna Pee Dee Belemnite).

The modern plants using a C 3 photosynthetic pathway (including most trees, woody shrubs, bushes, herbs and grasses) have an average isotopic δ 13 C value of -28.5‰ (global range -20 to -37‰), with -23‰ as the maximum value for typical C 3 plants and a cut-off of -31.5‰ for closed-canopy forests [START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF]. In this work, we use the average δ 13 C value of -27‰ for modern C 3 plants, excluding analyses from the understory of closed-canopy forests below -31.5‰ [START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF]. Modern plants that employ the C 4 photosynthetic pathway (primarily tropical grasses and sedges) have an average isotopic composition of -12‰ (global range -10 to -14‰) [START_REF] Cerling | Global vegetation change through the Miocene/Pliocene boundary[END_REF][START_REF] Cerling | Carbon isotope fractionation between diet and bioapatite in ungulate mammals and implications for ecological and paleoecological studies[END_REF][START_REF] Kohn | Stable isotope compositions of biological apatite. Phosphates Geochemical[END_REF]. The bivariate graphs were made with the Past 4.02 software [START_REF] Hammer | Past: Paleontological Statistics Software Package for Education and Data Analysis[END_REF]. All mean values in the text are followed by their standard deviation.

3.1.2 Estimation of enrichment factor, %C 4, δ 13 C diet-meq and MAP Abundance of atmospheric CO 2 has been changing over time [START_REF] Tipple | Carbon isotope ratio of Cenozoic CO 2 : A comparative evaluation of available geochemical proxies[END_REF] with a consequent influence on the carbon values of plants during its fixation in the photosynthesis process (Farquhar et al., 1989). To make a comparison between the carbon values of present-day plants with those consumed by animals in the past, it is crucial to perform corrections. In our work, we have corrected the δ 13 C values of modern plants by +1.5‰, due to the difference between the pre-Industrial δ 13 C CO2 value of ~ -6.5‰ established for the Plio-Pleistocene [START_REF] Tipple | Carbon isotope ratio of Cenozoic CO 2 : A comparative evaluation of available geochemical proxies[END_REF], and the δ 13 C CO2 value of ~ -8‰ at the time the reference collection of modern plants was collected [START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF]. When plants are consumed, a fixation occurs in the tooth enamel of the animals, a process of isotopic fractionation [START_REF] Krueger | Models for carbon isotope fractionation between diet and bone[END_REF][START_REF] Koch | Isotopic reconstruction of past continental environments[END_REF][START_REF] Cerling | Carbon isotope fractionation between diet and bioapatite in ungulate mammals and implications for ecological and paleoecological studies[END_REF][START_REF] Passey | Inverse methods for estimating primary input signals from timeaveraged isotope profiles[END_REF]. In this study, we use formula (1) in Tejada et al. 2018 which determines that there is a positive correlation between body mass and enamel-diet enrichment fractionation (expressed as ɛ* enamel-diet ). The ɛ* enamel-diet has been calculated from the estimation of the body mass of the species analyzed: S. maurusium [START_REF] Basu | The extinct, giant giraffid Sivatherium giganteum: Skeletal reconstruction and body mass estimation[END_REF], H. pomeli [START_REF] Bernor | Old world hipparion evolution, biogeography, climatology and ecology[END_REF], Gazella sp. and Alcelaphini [START_REF] Bibi | Continuous evolutionary change in Plio-Pleistocene mammals of eastern Africa[END_REF], M. phacochoeroides [START_REF] Rannikko | Adaptations of the Turkana Basin pigs (Suidae) to changing environments in the Plio-Pleistocene: tooth wear, diets and habitats[END_REF] and A. osiris [START_REF] Larramendi | Shoulder height, body mass, and shape of proboscideans[END_REF].

(1) ɛ* = 2.4 + 0.034 (Body Mass)

The δ 13 C values in plants and animals have also been proposed to estimate mean annual precipitation (MAP) in the fossil record. We use the formulae (2 and 3) developed in [START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF] and Kohn et al. (2015) to estimate the MAP, which applies corrections for altitude, latitude, and δ 13 C of atmospheric CO 2 from the average modern equivalent of

diet composition (δ 13 C diet-meq = δ 13 C enamel -ɛ* enamel-diet -Plio-Pleistocene atmospheric CO 2 ): (2) MAP = 10 ^ [Δ 13 C-2.01 + 0.000198 × elev -0.0129 × |lat| / 5.88] -300
where elev is elevation in meters, lat is latitude in degrees, and

(3) Δ 13 C = (δ 13 C atm -δ 13 C diet-meq )/(1 + δ 13 C diet-meq /1000) where δ 13 C atm is the carbon isotope of atmospheric CO 2 (-6.5‰ in the Plio-Pleistocene; [START_REF] Tipple | Carbon isotope ratio of Cenozoic CO 2 : A comparative evaluation of available geochemical proxies[END_REF] and δ 13 C diet-meq is the modern equivalent of diet composition (δ 13 C diet- meq ) estimated from δ 13 C enamel after ɛ* enamel-diet correction (see formula (1)).

We estimated (4) the fraction of C 4 vegetation consumed by AaO herbivores using δ 13 C modern plant values, -24‰ for C 3 vegetation ecosystems [START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF] and -12‰ for C 4 vegetation [START_REF] Cerling | Global vegetation change through the Miocene/Pliocene boundary[END_REF]. The fossil δ 13 C enamel values have been corrected for δ 13 C of Plio-Pleistocene atmospheric CO 2 and ɛ* enamel-diet to obtain the δ 13 C diet-meq.

(4) % C 4 = 100 × (δ 13 C diet-meq -δ 13 C C 3 )/( δ 13 C C 4 -δ 13 C C 3 )

Obligate drinkers vs. non-obligate drinkers taxa

To calculate relative aridity in AaO, we relied on the fundamental principle of different drinking behaviors exhibited by mammals [START_REF] Nicholson | First magnetostratigraphic results in the Aïn Beni Mathar-Guefaït Basin, Northern High Plateaus (Morocco): the Pliocene-Pleistocene Dhar Iroumyane composite section[END_REF][START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF][START_REF] Levin | A stable isotope aridity index for terrestrial environments[END_REF][START_REF] Blumenthal | Aridity and hominin environments[END_REF]. In arid environments, both open water sources and plant water and tissues experience evaporation of 16 O and enrichment of 18 O [START_REF] Gonfiantini | Oxygen isotopic composition of water in leaves[END_REF]. However, this evaporative effect is more pronounced in plants. As a result, it is anticipated that animals primarily obtaining water through plant consumption (nonobligate drinkers) will display higher δ 18 O enamel values compared to obligate drinkers relying on direct access to surface water [START_REF] Bocherens | Isotopic biogeochemistry ( 13 C, 18 O) of mammalian enamel from african pleistocene hominid sites[END_REF][START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF]. The greater the difference in δ 18 O values between these two groups, the higher the aridity [START_REF] Lehmann | Stable isotopic composition of fossil mammal teeth and environmental change in southwestern South Africa during the Pliocene and Pleistocene[END_REF][START_REF] Roberts | Fossil herbivore stable isotopes reveal middle Pleistocene hominin palaeoenvironment in 'Green Arabia[END_REF][START_REF] Lüdecke | Carbon, nitrogen, and oxygen stable isotopes in modern tooth enamel: A case study from Gorongosa National Park, central Mozambique[END_REF]. For this comparison, we selected the most reliable species from AaO to classify the mentioned categories.

Specifically, we chose S. maurusium and Gazella sp. as non-obligate drinkers, and H. pomeli and A. osiris as obligate drinkers. Generally, grazers among ungulates have a higher dependence on surface water than browsers (Western, 1975;Faith, 2018). This pattern is supported by the dental wear results from AaO, which classified S. maurusium and Gazella sp. as browsers and H. pomeli and A. osiris as grazers.

Dental wear analysis

Dental mesowear analysis

A total of 74 molars were studied using mesowear analysis, excluding 28 teeth that were unworn, extremely worn, or had broken or damaged cusp apices (Supplementary [START_REF] Rivals | Effect of ontogenetic-age distribution in fossil and modern samples on the interpretation of ungulate paleodiets using the mesowear method[END_REF]. The mesowear analysis method assesses the relief and sharpness of worn cusp apices, which are related to attritive and abrasive wear on dental enamel. These analyses were performed on the buccal side of upper molars and the lingual side of lower molars, with a preference for the paracone of the upper M2. To evaluate wear on teeth from P3 to M3, we used the extended mesowear method proposed by [START_REF] Kaiser | Extending the tooth mesowear method to extinct and extant equids[END_REF]. In this study, we applied the method introduced by Mihlbachler et al. ( 2011), which uses seven cusp categories ranging from high and sharp (stage 0) to completely blunt with no relief (stage 6). A low-abrasion diet such as browsing, which induces high attrition, preserves sharpened apices on buccal cusps as teeth wear down, while a high-abrasion diet results in more rounded and blunted buccal cusp apices. The bivariate graph was performed with the Past 4.02 software [START_REF] Hammer | Past: Paleontological Statistics Software Package for Education and Data Analysis[END_REF].

Dental microwear analysis

The investigation of dental microwear has a rich history in elucidating the dietary preferences and ecological niches of fossil species. Starting with early studies in the late 1970s, which employed scanning electron microscopy (SEM) at high magnifications (∼100-500x) [START_REF] Rensberger | Scanning electron microscopy of wear and occlusal events in some small herbivores[END_REF][START_REF] Walker | Microwear of mammalian teeth as an indicator of diet[END_REF], to subsequent research employing low-magnification light microscopy [START_REF] Macfadden | Ancient Diets, Ecology, and Extinction of 5-Million-Year-Old Horses from Florida[END_REF][START_REF] Solounias | Advances in the Reconstruction of Ungulate Ecomorphology with Application to Early Fossil Equids[END_REF], and more recently, dental microwear texture analysis (DMTA) utilizing three-dimensional surface measurements acquired through white-light confocal microscopy and scale-sensitive fractal analysis [START_REF] Ungar | Quantification of dental microwear by tandem scanning confocal microscopy and scale-sensitive fractal analyses[END_REF][START_REF] Scott | Dental microwear texture analysis: technical considerations[END_REF].

Despite all methods being valid and complementary, for this study, we opted for at lowmagnification microwear approach due to the accessibility of an extensive microwear reference collection of extant species, particularly those of African origin [START_REF] Solounias | Advances in the Reconstruction of Ungulate Ecomorphology with Application to Early Fossil Equids[END_REF].

In this work, a total of 109 molars and premolars were selected and molded. After examination of the molds under a stereomicroscope, 49 specimens were discarded due to poor preservation or taphonomic defects (Supplementary ). Scoring of microwear features, including small and large pits (round scars), scratches (elongated scars with parallel sides), gouges (irregular edges and much larger and deeper than the large pits), puncture pits (deepest at their centers, symmetrical, craterlike features with regular margins), and cross scratches (oriented perpendicularly to the majority of scratches), was performed using a standard 0.16 mm 2 ocular reticle. In order to achieve a more precise categorization of grazers, browsers, and mixed feeders, we used the percentage of individuals in a sample possessing scratch numbers that fall between 0 and 17 [START_REF] Semprebon | Was grass more prevalent in the pronghorn past? An assessment of the dietary adaptations of Miocene to Recent Antilocapridae (Mammalia: Artiodactyla)[END_REF]. The scratch width score (SWS) was calculated based on the ratio of fine to coarse scratches ("0" predominantly fine scratches per tooth surface, "1" to those with a mixture of fine and coarse scratches, and "2" to those with predominantly coarse scratches). The results were compared with a database constructed from extant ungulate taxa [START_REF] Solounias | Advances in the Reconstruction of Ungulate Ecomorphology with Application to Early Fossil Equids[END_REF][START_REF] Rivals | Dietary plasticity in ungulates: Insight from tooth microwear analysis[END_REF]. To reduce inter-observer error, dental microwear analysis was conducted by a single experienced researcher (IRP).

Results

Stable isotopes (δ 13 C and δ 18 O)

The δ 13 C values of all taxa measured in AaO ranged from -14.1 to -8‰ with a mean and standard deviation of -11.4 ± 1.2‰ (n = 82) (Fig. 2). The data for each species are The δ 18 O values ranged from -3 to 2.9‰ with a mean and standard deviation of -0.6 ± 1.2‰ (n = 82) (Fig. 3). The data for each species are described below: H. pomeli (n = 16; range = -3 to 0.2‰; mean = -1.8 ± 0.9‰), Alcelaphini (n = 18; range = -2.2 to 0.6‰; mean = -0.8 ± 0.7‰), Gazella sp. (n = 18; range = -2.3 to 2.1‰; mean = -0.2 ± 1.3‰), S. maurusium (n = 6; range = -0.9 to 2.9‰; mean = 1.2 ± 1.3‰), M.

phacochoeroides (n = 23; range = -1.8 to 2‰; mean = -0.4 ± 0.9‰) and A. osiris (n = 1; -1.4‰). The whole isotopic dataset is provided in Supplementary Table 1. pomeli) and non-obligate drinkers (n = 24; S. maurusium and Gazella sp.) with a pvalue of 1.819. The non-obligate drinkers mean is 0.15‰ and the obligate drinker mean is-1.77‰, implying a difference between the two groups of 1.9‰.

Dental wear analysis

Dental mesowear analysis

Some authors have observed differences in the mesowear score between the upper and lower molars of the same individuals [START_REF] Kaiser | Differential Mesowear in Occluding Upper and Lower Molars: Opening Mesowear Analysis for Lower Molars and Premolars in Hypsodont Horses[END_REF]. Since the Gazella sp.

and Alcelaphini teeth analysed include both upper and lower molars, we conducted an ANOVA statistical test and Tukey's pairwise comparison to enhance the analysis conducted. The statistical results did not reveal significant differences in the mesowear score values between lower molars (n = 5) and upper molars (n = 12) of Gazella sp., with a p-value of 0.9694, nor between lower molars (n = 13) and upper molars (n = 9) of Alcelaphini, with a p-value of 0.9826. The mesowear pattern of AaO specimens is characterized by occlusal surfaces ranging from sharp cusps and high relief (low abrasion) to low relief with rounded cusps (high abrasion). It corresponds to mesowear scores with values from 0 to 5 (Table 2; Fig. 4).

All three Bovidae have sharp cusps, which means that attrition predominates strongly over abrasion. The S. maurusium has the lowest level of abrasion with a MWS of 1, falling in the MWS average of extant leaf browsers. The Gazella sp. has also a low average MWS (1.2), being in the range of MWS of extant mixed feeders but with a tendency towards a browsing diet. The Alcelaphini, with variability in abrasion levels, has an average MWS of 2.2 and is categorized as a grass-dominated mixed feeder. In the case of the Equidae H. pomeli, the MWS indicates high levels of abrasion, with a MWS average of 4.3. This pattern places H. pomeli among extant grazers. Extant ungulates database [START_REF] Fortelius | Functional Characterization of Ungulate Molars Using the Abrasion-Attrition Wear Gradient: A New Method for Reconstructing Paleodiets[END_REF].

Dental microwear analysis

At AaO, all herbivores display browsing or mixed feeding dietary traits (Fig. 5). The 2, NS and 0-17%) indicates a high proportion of grasses in their diet.

The SWS, being between 0.9 and 1.1, indicates a mixture of both fine and coarse scratches for all species. Hyper-coarse scratches have been found only in A. osiris.

Cross scratches are absent in H. pomeli and present in a low percentage in Alcelaphini, Gazella sp. and S. maurusium. A. osiris and M. phacochoeroides have them in 100% of the individuals. This trait is characteristic of animals with a bunodont dental morphology as in the case of the latter two species. Gouges have been observed in all species except in A. osiris and their presence is remarkable in the four individuals of S.

maurusium. Puncture pits are present in a low percentage in Alcelaphini, H. pomeli and M. phacochoeroides, and large pits are present in all species in proportions varying from 50% to 100% of the individuals.

Discussion

Palaeodiet

The combination of the three approaches allows us to characterize the dietary preferences of the different taxa, as well as to reconstruct the general ecological context (Table 3). In AaO, all species have a predominantly plant-based C 3 diet with values ranging from -14 to -8‰, with a small consumption of C 4 plants in Alcelaphini and M.

phacochoeroides (Table 1). In some contexts, interpreting the carbon isotopic signal can be complex, especially when there are no extreme values that can indicate high consumption of C 4 plants linked to grass consumption (ca. δ 13 C > 0‰; [START_REF] Cerling | Carbon isotope fractionation between diet and bioapatite in ungulate mammals and implications for ecological and paleoecological studies[END_REF] or the presence of C 3 closed canopy forests (ca. δ 13 C < -16‰; Kohn, 2010), types of environments in which the signal is obvious. In AaO, there is both interand intra-species variability in carbon values. Recent isotopic studies on extant species in sub-Saharan Africa have shown a weak relationship between intra-taxon variation in δ 13 C enamel (C 3 and C 4 ) and corresponding changes in herbivore diet and vegetation structure (woody cover). Therefore, adopting a community-level approach when making inferences about vegetation using isotopic data, focusing on the relationships between different taxa is recommended. This approach allows for a more accurate understanding of the vegetation dynamics and ecological context [START_REF] Robinson | Intrataxonomic trends in herbivore enamel δ 13 C are decoupled from ecosystem woody cover[END_REF]. In AaO, the interspecific difference between Alcelaphini and S. maurusium is striking and could represent different ecological niches and diets (Fig. 2). Dental wear analysis (micro-and mesowear) shows variable feeding traits that range from browser to mixed-feeder to grazer behavior, including Alcelaphini with a grass-dominated, mixed-feeding diet or S. maurusium as the most browsing taxon (Table 3). Oxygen isotope data are consistent with the dental wear feeding pattern, with browser species having more positive values (S. maurusium and Gazella sp.) than the rest, and grass-dominated mixed feeders having more negative values. The correlation in oxygen is higher between the most grazing species, according to dental wear pattern, such as H. pomeli, and the most browsing ones such as S. maurusium, showing very distant values between them. This could suggest the consumption of different resources, such as the preference for grasses by the former and leaves by the latter.

Species

Stable isotopes

Mesowear Microwear

S. maurusium

C 3 B B Alcelaphini C 3 (C 4 ) MF-G MF-G Gazella sp. C 3 MF-B B H. pomeli C 3 G MF-G M. phacochoeroides C 3 (C 4 ) - MF-G A. osiris C 3 - MF-G

Comparison of AaO with other African sites

The Sivatherium maurusium from AaO has the most negative C 3 carbon values (δ 13 C mean = -12.4 ± 1.4‰) and the most positive oxygen values (Fig. 2 and 3) compared to other AaO species. These oxygen and carbon values could be attributed to the preferential consumption of leaves from the upper parts of trees or shrubs which is consistent with dental wear patterns suggesting a browsing diet for AaO S. maurusium.

The same isotopic pattern in δ 13 C and δ 18 O values has also been observed in Sivatherium from Hadar and Aramis (Ethiopia; ~4-3 Ma) [START_REF] Wynn | Dietary flexibility of Australopithecus afarensis in the face of paleoecological change during the middle Pliocene: Faunal evidence from Hadar, Ethiopia[END_REF] In East Africa, the Giraffidae were represented by two genera: Giraffa and Sivatherium, from the early Pliocene onwards. Sivatherium became extinct during the Middle Pleistocene. Overall, its diet underwent changes in the Turkana Basin (Kenya), being a browser (C 3 plants) at ~4 Ma and switching to grazing (C 4 plants) between ~2.5 and 1

Ma [START_REF] Cerling | Dietary changes of large herbivores in the Turkana Basin, Kenya from 4 to 1 Ma[END_REF]. In the Chiwondo beds (Malawi; ~2.5 Ma), Sivatherium exhibited less negative δ 13 C values (n = 1; δ 13 C= -7.9‰) than the purely browsing fossil Giraffa (n = 2; δ 13 C mean = -12.1 ± 1.1‰), indicating that it incorporated some C 4 grass in its diet [START_REF] Bocherens | Hominin palaeoecology in Late Pliocene Malawi: First insights from isotopes ( 13 C, 18 O) in mammal teeth[END_REF]. In Olduvai (Tanzania; ~1.8 Ma), a multiproxy approach suggested a mixed diet for S. maurusium, C 4 -dominated or mixed diets, a mesowear characteristic of grazers, but with microwear indicating a browsingdominated mixed diet, likely due to seasonal changes in its diet [START_REF] Uno | Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses[END_REF].

In South Africa, Sivatherium maintained its preference for C 3 plants from ~5 to 3 Ma. In the Langebaanweg site (~5 Ma), the δ 13 C mean value (n = 26) is -11.5 ± 1.1‰ [START_REF] Franz-Odendaal | New evidence for the lack of C 4 grassland expansions during the early Pliocene at Langebaanweg, South Africa[END_REF]. However, hypsodonty indices, dental mesowear, and dental microwear suggested mixed feeding dietary traits with a browsing tendency for this species [START_REF] Franz-Odendaal | Comparative dietary evaluations of an extinct giraffid (Sivatherium hendeyi) (Mammalia, Giraffidae, Sivatheriinae) from Langebaanweg, South Africa (early Pliocene)[END_REF]). In the Makapansgat Limeworks Member 3 (~3 Ma), Sivatherium exhibited carbon values (n = 2; δ 13 C mean = -11.4 ± 0.1‰) similar to those of Giraffa (n = 8; δ 13 C mean = -11 ± 0.9‰) at the same site [START_REF] Sponheimer | The First Humans: A Summary Perspective on the Origin and Early Evolution of the Genus Homo[END_REF].The diet of AaO Sivatherium follows the same C 3browser pattern as that of the rest of Africa during the ~3 to 2.5 Ma period, but further multiproxy studies are needed in more recent North African sites such as Aïn Hanech or El-Kherba (~1.8 Ma) to determine whether this dietary pattern remains the same or changes, as in the case of East Africa.

The Alcelaphini from AaO is the taxon with the least negative carbon values, with a predominance of C 3 plant consumption values (mean δ 13 C = -10.3 ± 1.3‰), indicating even some C 4 consumption (Table 2). The results of micro-and mesowear tooth analysis indicate a mixed diet, but with a high content of grasses in its feeding ecology.

In general, this taxon is indicative of open dry environments, both during the African Pliocene and Pleistocene and in extant populations. Regardless of the consumption of C 3 or C 4 plants, their feeding behavior is predominantly grazing [START_REF] Vrba | Evolutionary Pattern and Process in the Sister-Group Alcelaphini-Aepycerotini (Mammalia: Bovidae)[END_REF][START_REF] Sponheimer | Combining isotopic and ecomorphological data to refine bovid paleodietary reconstruction: A case study from the Makapansgat Limeworks hominin locality[END_REF]2003;[START_REF] Bobe | The expansion of grassland ecosystems in Africa in relation to mammalian evolution and the origin of the genus Homo[END_REF][START_REF] Cerling | Dietary changes of large herbivores in the Turkana Basin, Kenya from 4 to 1 Ma[END_REF].

Different species of Alcelaphini were present in North Africa from the Late Pliocene [START_REF] Arambourg | Vertébrés villafranchiens d'Afrique du Nord (Artiodactyles, Carnivores, Primates, Reptiles, Oiseaux)[END_REF]Geraads & Amani, 1998) until they were declared extinct in this area in 1994 [START_REF] Mallon | Antelopes: North Africa, the Middle East, and Asia[END_REF], but the only fossil record of their diet has been carried out at the site of Tighennif (1 Ma; Algeria). At this site, the Alcelaphini tribe is represented by the species Connochaetes taurinus prognu. The pattern of δ 13 C values (n = 6; mean δ 13 C = -10.5 ± 1.4‰) is similar to that observed in the Alcelaphini from AaO [START_REF] Bocherens | Isotopic biogeochemistry ( 13 C, 18 O) of mammalian enamel from african pleistocene hominid sites[END_REF][START_REF] Fannin | Carbon and strontium isotope ratios shed new light on the paleobiology and collapse of Theropithecus, a primate experiment in graminivory[END_REF]. Compared to the carbon values of different ungulates analyzed in Tighennif, this species has the most positive carbon values, indicating, as in the case of AaO, a small consumption of C 4 plants in some individuals.

In central Africa, 2500 km west of the Rift Valley, at the Koro Toro site (Chad; ~3.5-3

Ma), Alcelaphini have a grazing diet based on C 4 plants with an average δ 13 C value (n = 6) of 1.4 ± 0.8‰ [START_REF] Zazzo | Herbivore paleodiet and paleoenvironmental changes in Chad during the Pliocene using stable isotope ratios of tooth enamel carbonate[END_REF].

In eastern Africa (Turkana Basin), the remarkable predominance and similarity in the C 4 isotopic signature of Alcelaphini from approximately ~4.4 Ma to present-day specimens is particularly notable [START_REF] White | Macrovertebrate paleontology and the Pliocene habitat of Ardipithecus ramidus[END_REF][START_REF] Cerling | Dietary changes of large herbivores in the Turkana Basin, Kenya from 4 to 1 Ma[END_REF]. In Olduvai (Tanzania;

~1.8 Ma), the carbon isotope data indicate C 4 -dominated diets, while dental wear classifies this species as a grass-dominated mixed feeder [START_REF] Uno | Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses[END_REF].

In southern Africa, Wonderwerk Cave has a longer temporally stratified sequence from the Early Pleistocene to the Holocene, with the presence of Alcelaphini in all layers.

They show a progressive increase in C 4 consumption from 50% in the Early Pleistocene to 100% in the Holocene [START_REF] Ecker | The palaeoecological context of the Oldowan-Acheulean in southern Africa[END_REF]. In the Makapansgat Limeworks Member Ecomorphological and microwear data confirm a grazing diet for the former and a browsing for the latter [START_REF] Sponheimer | Combining isotopic and ecomorphological data to refine bovid paleodietary reconstruction: A case study from the Makapansgat Limeworks hominin locality[END_REF][START_REF] Schubert | Microwear evidence for Plio-Pleistocene bovid diets from Makapansgat Limeworks Cave, South Africa[END_REF]. In Haasgat cave (~2.6-1.9 Ma), as in Makapansgat, Alcelaphini have a C 4 consumption while

Tragelaphini have C 3 plant consumption values [START_REF] Adams | New faunal stable carbon isotope data from the Haasgat HGD assemblage, South Africa, including the first reported values for Papio angusticeps and Cercopithecoides haasgati[END_REF]. In Swartkrans cave (~1.9-1.8 Ma), the Alcelaphini Connochaetes sp. also has a C 4 -based diet (Lee- et al., 1989). However, in other South African sites, the Alcelaphini carbon values are clearly C 3 , although attributed to grass consumption. This is the case of Hoedjiespunt (~0.35-0.25 Ma) with a mean δ 13 C (n = 16) of -9.8 ± 1.3‰, Elandsfontein (~1.0-0.6 Ma) with a mean δ 13 C (n = 19) of -10.3 ± 1.2‰, and Langebaanweg (~5 Ma)

Thorp
with a mean δ 13 C (n = 7) of -10.8 ± 1‰ [START_REF] Lehmann | Stable isotopic composition of fossil mammal teeth and environmental change in southwestern South Africa during the Pliocene and Pleistocene[END_REF].

The Hipparion pomeli from AaO has a diet based on C 3 plants (δ 13 C mean = -11.7 ± 0.9‰). It is the species with the highest mesowear, indicative of a grazing diet.

Microwear classifies it as a mixed feeder, but the high number of scratches is related to a high consumption of grasses. The presence of Hipparion between ~3.5 and 1.7 Ma is well documented in North Africa in sites such as Aïn Brimba and Lake Ichkeul in Regarding studies on the feeding habits of this species in North Africa, there are only preliminary results for the Hipparion sp. from the Guefaït site (~3-2.5 Ma; Morocco), which show a predominance of C 3 plant consumption (n = 4; δ 13 C mean = -9.5 ± 1‰), although with less negative carbon values than those of the H. pomeli from AaO [START_REF] Ramírez-Pedraza | Multiproxy approach to reconstruct fossil primate feeding behavior: Case study for macaque from the Plio-Pleistocene site Guefaït-4.2 (eastern Morocco)[END_REF].

In Central Africa, diachronic (~6-3 Ma) isotopic studies carried out on the species Hipparion cf. hasumense in Chad show a clear predominance of C 4 plant consumption.

In Kossom Bougoudi (~6-5 Ma), the average δ 13 C (n = 6) is -1.3 ± 0.8‰, and in the Koro Toro site (~3.5-3 Ma) the average δ 13 C value (n = 2) is 0.9 ± 1.1‰ [START_REF] Zazzo | Herbivore paleodiet and paleoenvironmental changes in Chad during the Pliocene using stable isotope ratios of tooth enamel carbonate[END_REF].

In East Africa, as was the case with the Alcelaphini, the hipparion equid Eurygnathohippus has continuity in C 4 -grazer plant consumption from ~4 to 1.5 Ma [START_REF] Bocherens | Hominin palaeoecology in Late Pliocene Malawi: First insights from isotopes ( 13 C, 18 O) in mammal teeth[END_REF][START_REF] Cerling | Dietary changes of large herbivores in the Turkana Basin, Kenya from 4 to 1 Ma[END_REF][START_REF] Manthi | Diets of mammalian fossil fauna from Kanapoi, northwestern Kenya[END_REF]. Other methods such as microwear and mesowear also indicate a grazing diet for the Eurygnathohippus from Olduvai (Tanzania; ~1.8 Ma) [START_REF] Uno | Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses[END_REF].

In southern Africa, the Hipparion from Langebaanweg (~5 Ma) has a δ 13 C mean value (n = 6) of -11.3 ± 0.9‰, implying a consumption of C 3 plants [START_REF] Franz-Odendaal | New evidence for the lack of C 4 grassland expansions during the early Pliocene at Langebaanweg, South Africa[END_REF]. Other lines of evidence, such as mesowear analysis, in this species are consistent with grazing behavior [START_REF] Franz-Odendaal | Systematics and dietary evaluation of a fossil equid from South Africa[END_REF]. Therefore, it would have a diet based on C 3 grasses, like the H. pomeli from AaO. In contrast, at the Makapansgat site (~3 Ma), the Hipparion indicates C 4 plant consumption [START_REF] Sponheimer | The First Humans: A Summary Perspective on the Origin and Early Evolution of the Genus Homo[END_REF][START_REF] Lee-Thorp | Stable isotopes in fossil hominin tooth enamel suggest a fundamental dietary shift in the Pliocene[END_REF]. In general, during the African Plio-Pleistocene, Hipparion had a diet mainly based on the consumption of C 4 grasses. Grass consumption has also been observed in AaO, although with the intake of C 3 plants. Africa, but is also known from its type-locality Aïn Jourdel [START_REF] Thomas | Recherches stratigraphiques et paléontologiques sur quelques formations d'eau douce de l'Algérie[END_REF].

In East Africa, Metridiochoerus between ~4 and 1 Ma were predominantly grazers with high C 4 -grazer proportions [START_REF] Harris | Dietary adaptations of extant and Neogene African suids[END_REF][START_REF] Cerling | Dietary changes of large herbivores in the Turkana Basin, Kenya from 4 to 1 Ma[END_REF][START_REF] Uno | Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses[END_REF]. Dental microwear analysis conducted on Metridiochoerus from Olduvai (~1.8

Ma, Tanzania) points to mixed feeding and grazing behavior [START_REF] Uno | Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses[END_REF]. In the Chiwondo Beds in Malawi (~2.5-1.5 Ma), M. andrewsi and M. compactus exhibit a predominant consumption of C 3 plants [START_REF] Lüdecke | Persistent C 3 vegetation accompanied Plio-Pleistocene hominin evolution in the Malawi Rift (Chiwondo Beds, Malawi)[END_REF].

Little is known about the diet of Metridiochoerus in South Africa. Some populations of M. andrewsi from Elandsfontein (~1.0-0.6 Ma) were consuming mostly C 3 plants [START_REF] Luyt | New light on Middle Pleistocene west coast environments from Elandsfontein, Western Cape Province, South Africa[END_REF], but due to the overall predominance of C 3 plants in this area, as in the Chiwondo Beds in the Malawi Rift, could have been including grasses in their diet as well.

The Gazella sp. from AaO has carbon values that correspond to a C 3 plant-based diet (mean δ 13 C = -11.6 ± 0.6‰). Microwear analysis shows a browser pattern; however, mesowear analysis indicates a mixed diet with a browsing tendency. This could imply a more purely browsing diet over a relatively brief period and a more varied consumption of plants, including grasses in their diet, for most of the year. As with Alcelaphini, Gazella has been present in North Africa since the Pliocene [START_REF] Sahnouni | Ecological background to Plio-Pleistocene hominin occupation in North Africa: The vertebrate faunas from Aïn Boucherit, Aïn Hanech and El-Kherba, and paleosol stable-carbon-isotope studies from El-Kherba, Algeria[END_REF][START_REF] Van Der Made | The North African earliest Pleistocene faunal sequence: from biostratigraphy to biochronology[END_REF] until the present day in Morocco, Algeria, and Tunisia [START_REF] Schmid | Mammal species of the world: A taxonomic and geographic reference[END_REF].

In North Africa, isotopic studies have been carried out on this species in both Tighennif (~1 Ma; Algeria) with a mean δ 13 C value (n = 5) of -11.9 ± 0.9‰ and Guefaït (~3-2.5

Ma; Morocco) with a mean δ 13 C value (n = 4) of -10.9 ± 1.1‰. At both sites, there is a clear predominance of C 3 plant consumption by Gazella [START_REF] Fannin | Carbon and strontium isotope ratios shed new light on the paleobiology and collapse of Theropithecus, a primate experiment in graminivory[END_REF][START_REF] Ramírez-Pedraza | Multiproxy approach to reconstruct fossil primate feeding behavior: Case study for macaque from the Plio-Pleistocene site Guefaït-4.2 (eastern Morocco)[END_REF].

In East Africa, Gazella janenschi from the Laetolil Beds (∼4.3-3.5 Ma) has carbon values ranging from -1.9 to -9.8‰, implying a variable diet from C 4 -grazing to C 3browsing [START_REF] Kingston | Isotopic dietary reconstructions of Pliocene herbivores at Laetoli: Implications for early hominin paleoecology[END_REF]. This dietary flexibility has also been observed in different Antilopini analyzed in the Turkana Basin (Kenya), with extracted proportions of the isotopic signal of 17% C 4 -grazing, 75% mixed C 3 -C 4 , and 8% C 3browsing for the period of ~4.3 to 2.3 Ma, and 54% C 4 -grazing, 46% mixed C 3 -C 4 , and 0% C 3 -browsing for the period ~2.3 to 1.0 Ma [START_REF] Cerling | Dietary changes of large herbivores in the Turkana Basin, Kenya from 4 to 1 Ma[END_REF]. The multiproxy study (isotopes, microwear, and mesowear) of Antilopini from Olduvai (1.8 Ma) also indicates a mixed feeder diet [START_REF] Uno | Large mammal diets and paleoecology across the Oldowan-Acheulean transition at Olduvai Gorge, Tanzania from stable isotope and tooth wear analyses[END_REF]. The Gazella sp. from AaO, as well as those from the Pleistocene and Pliocene in Africa in general, seem to have the plasticity to consume distinct types of plants, adapting to seasonal availability. Even in East Africa before ~2.3 Ma, with a predominance of C 4 grassland in the area, they maintain a percentage of contribution from C 3 plant consumption.

In South Africa, Gazella vanhoepeni from Makapansgat (~3 Ma) is considered either a browser or a mixed-feeder preferring browsing based on isotopic, ecomorphological, microwear, and mesowear dental studies [START_REF] Schubert | Microwear evidence for Plio-Pleistocene bovid diets from Makapansgat Limeworks Cave, South Africa[END_REF]. The diachronic and multiproxy study (isotopes, dental microwear texture, and mesowear analysis) of Antilopini (Antidorcas) from Sterkfontein Member 4 (~2.8-2 Ma) and Swartkrans Members (~2-0.8 Ma) also indicates a mixed diet with a certain browsing tendency for this genus [START_REF] Sewell | Using springbok (Antidorcas) dietary proxies to reconstruct inferred palaeovegetational changes over 2 million years in Southern Africa[END_REF].

Palaeohabitat and palaeoclimate

The results of the combination of proxies suggest for AaO a landscape with a predominance of open and dry habitat, composed of C 3 woody plants and grasses and a low presence of C 4 plants . The closed canopy forest is absent in the surroundings of AaO, since no species has δ 13 C diet-meq values below -31.5‰, which is established as a limit for this habitat.

Dry environment and seasonality

The Mean Annual Precipitation (MAP) in AaO measured 385 mm/year, indicating a dry climate. The aridity of the region is supported by the fact that environments dominated by C 3 plants with a MAP of 500 mm/year or less are typically associated with arid conditions. This aridity pattern is also evident in the Tighenif site (1 Ma; Algeria), recording a MAP of 297 mm/year (Supplementary Table 3). This reinforces the enduring prevalence of dry climates even with established hominin presence in North Africa. [START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF] argues that the indicator's reliability depends on the mean MAP of all analyzed taxa. Thus, the average MAP remains the critical factor for assessing the robustness of this indicator. However, the variability in δ 13 C enamel , MAP, and δ 13 C diet-meq values, both inter-and intra-species (Table 1), suggests the presence of microhabitats [START_REF] Mercader | Earliest Olduvai hominins exploited unstable environments ~ 2 million years ago[END_REF]. In arid regions like those surrounding AaO and Tighenif, there can be localized areas of higher humidity, particularly in close proximity to water sources. Vegetation in these zones may exhibit lower δ 13 C values than expected for the surrounding dry environment, especially in a particularly wet year or season [START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF]. This variability in the values could also be explained by the dynamics of the assemblage accumulation. Although the formation data of the site suggest a rapid accumulation over time (Geraads et al., 2022), we cannot precisely determine how long it took to form, potentially encompassing many years with diverse climates and resources for consumption.

In dry environments, C 4 plants exhibit greater efficiency than C 3 plants under conditions of low atmospheric CO 2 concentration, high temperatures, and moisture stress [START_REF] Ehleringer | Climate change and the evolution of C 4 photosynthesis[END_REF][START_REF] Cerling | Expansion of C 4 ecosystems as an indicator of global ecological change in the late Miocene[END_REF]. Therefore, the presence of C 4 plants in the diet of Alcelaphini and M. phacochoeroides, even in small proportions, aligns with arid environments. The variability in δ 13 C enamel values within species, especially in the aforementioned species, may suggest the existence of pronounced seasonal fluctuations.

Relative to aridity, the difference observed in the δ 18 O values of obligate and nonobligate drinkers in AaO (1.9‰) is slightly higher than the difference found in herbivores from the Tsavo (1.7‰ ) region (Kenya), which has been defined as a dry savannah with vegetation characterized by semi-desert bushland with riparian woodland and a MAP of 500 mm/yr [START_REF] Cerling | Diets of East African Bovidae based on stable isotope analysis[END_REF]2015). The species S. maurusium exhibits the highest δ 18 O values, even in comparison to Gazella sp. Given that dental wear patterns indicate a browsing diet for both species, the elevated δ 18 O values in S.

maurusium may be attributed to its consumption of leaves from tall plants that it has access to due to its large size. Sun-exposed leaves, particularly in arid conditions, are highly sensitive to evaporative fractionation, resulting in an enrichment of 18 O [START_REF] Gonfiantini | Oxygen isotopic composition of water in leaves[END_REF][START_REF] Barbour | Stable oxygen isotope composition of plant tissue: A review[END_REF].

In this line, the combination of tooth microwear (short-term) and tooth mesowear (longterm) proxies has been used as a tool to identify seasonality [START_REF] Sánchez-Hernández | Tale of two timescales: Combining tooth wear methods with different temporal resolutions to detect seasonality of Palaeolithic hominin occupational patterns[END_REF]. Considering that microwear reflects the signal of a short-term diet, such as a single season, while mesowear reflects a longer period including probably all seasons, discrepancies in the results between both proxies would be indicative of dietary changes due to seasonal availability of resources. In AaO, S. maurusium exhibits a browsing pattern with the two proxies, indicating that its diet does not change throughout the year. For Gazella sp., tooth mesowear indicates browse-dominated mixed feeding, while microwear suggests browsing. This species is likely to have a more diverse diet, characterized by a higher consumption of grasses throughout the year, along with a significant increase in browsing during a particular season. In the case of Alcelaphini and H. pomeli, tooth mesowear indicates grass-dominated mixed feeding and grazing, respectively, while microwear suggests mixed feeding. It indicates a predominant consumption of grasses throughout the year with the introduction of other food items during specific periods of the year.

C 3 grassland and open habitat

In all species from AaO, the most discriminant microwear feature is the number of scratches, which is different in browsers and mixed feeders (Fig. 5). The high number of scratches in mixed feeders indicates significant consumption of grasses (see %0-17

in Table 2). However, the number of pits is very similar between browsers and mixed feeders with grazing tendencies. The relatively high number of pits and the presence of large pits in all species could be caused by incidental ingestion of abrasive grit resulting from feeding close to the ground in open and arid habitats [START_REF] Semprebon | Was grass more prevalent in the pronghorn past? An assessment of the dietary adaptations of Miocene to Recent Antilocapridae (Mammalia: Artiodactyla)[END_REF][START_REF] Hoffman | Controlled feeding trials with ungulates: a newapplication of in vivo dental molding to assess the abrasive factors of microwear[END_REF]. This enables us to emphasize two environmental aspects:

(1) The prevalence of taxa with a C 3 plant-based diet, many of which consume a significant amount of grasses, indicating the significant presence of C 3 grasslands in the study area. This assertion is corroborated by previous research on the feeding habits of

Theropithecus atlanticus in AaO. In that study, they employed time-and graminivorecalibrated carbon stable isotope values to illustrate a progressive transition towards an increased dependence on high-throughput bulk-feeding graminivory and proposed a consumption of grasses exhibiting a distinct C 3 isotopic signature [START_REF] Fannin | Carbon and strontium isotope ratios shed new light on the paleobiology and collapse of Theropithecus, a primate experiment in graminivory[END_REF].

(2) The presence of C 3 grassland, feeding close to the ground, and the presence of T.

atlanticus [START_REF] Alemseged | Theropithecus atlanticus (Thomas, 1884) (Primates: Cercopithecidae) from the late Pliocene of Ahl al Oughlam, Casablanca, Morocco[END_REF][START_REF] Fannin | Carbon and strontium isotope ratios shed new light on the paleobiology and collapse of Theropithecus, a primate experiment in graminivory[END_REF] are indicators of open habitats. It is noteworthy that no other cercopithecine species have been discovered at the AaO site in Morocco. Additionally, while no fossil remains of Theropithecus have been found at the contemporaneous site of Guefaït in Morocco, the presence of M. cf.

sylvanus has been noted [START_REF] Alba | New macaque fossil remains from Morocco[END_REF]. Previous ecological studies suggest that this macaque inhabited a woodland ecosystem, where it had a folivorous-frugivorous diet with hard item consumption which was primarily based on C 3 plants ( Ramirez-Pedraza et al., 2023). This indicates a low wood cover in the landscape of western Morocco during the Plio-Pleistocene boundary. In the same line, the relative frequency of two species of bovids found in Guefaït and AaO may provide insight into the predominant environmental conditions. Specifically, Tragelaphini are associated with wooded and humid habitats, while Alcelaphini are linked to more open environments [START_REF] Bobe | Patterns of abundance and diversity in late Cenozoic bovids from the Turkana and Hadar Basins, Kenya and Ethiopia[END_REF]. Notably, the abundance of Alcelaphini and the scarcity of Tragelaphini in AaO is significant (Geraads and Amani, 1998;Geraads et al., 2022a), while the opposite trend is observed in Guefaït [START_REF] Sala-Ramos | Pleistocene and Holocene peopling of Jerada province, eastern Morocco: introducing a research project. Le peuplement humain pendant le Pléistocène et l'Holocène dans la province de Jerada[END_REF][START_REF] Ramírez-Pedraza | Multiproxy approach to reconstruct fossil primate feeding behavior: Case study for macaque from the Plio-Pleistocene site Guefaït-4.2 (eastern Morocco)[END_REF]. Previous works on AaO have used a method for predicting palaeohabitats using measurements (height/width proportions) of bovid astragali [START_REF] Degusta | A method for inferring paleohabitats from the functional morphology of bovid astragali[END_REF]. The proportions of this bone in the bovids from AaO confirm the absence of heavy wood cover and the predominance of open habitat (Geraads et al., 2022a).

Conclusion

This research highlights the importance of integrating different proxies for palaeoecological reconstructions, being particularly useful in areas where there is a predominance of C 3 plants such as in North Africa, where it is more challenging to define the diet and habitat of mammals from stable isotope analysis alone. In this work, the complementarity of dental wear analysis has allowed us to determine diets that range from grazing to browsing behavior. Our multiproxy analysis indicates that during

Fig. 1 .

 1 Fig.1. Location map of North African sites mentioned in the text. Plio-Pleistocene boundary sites = orange circle (Ahl al Oughlam (this study), Guefaït and Aïn Jourdel); Early Pleistocene sites = brown circle (Thomas Quarry I-Unit L, Tighennif, Aïn Boucherit, Aïn Hanech, El Kherba and Mansourah); Middle Pleistocene sites = green circle (Grotte des Rhinocéros and Grotte à Hominidés).

  described below: H. pomeli (n = 16; range = -13.5 to -10.6‰; mean = -11.7 ± 0.9‰), Alcelaphini (n = 18; range = -13 to -8‰; mean = -10.3 ± 1.3‰), Gazella sp. (n = 18; range = -12.8 to -10.6‰; mean = -11.6 ± 0.6‰), S. maurusium (n = 6; range = -14.1 to -10.8‰; mean = -12.4 ± 1.4‰), M. phacochoeroides (n = 23; range = -13.2 to -8.4‰; mean = -11.7 ± 1.2‰) and A. osiris (n = 1; -13.3‰). The two taxa with the highest variability and the most positive values are Alcelaphini and M. phacochoeroides. Gazella sp. and H. pomeli are the species with the lowest variability and S. maurusium is the species with the most negative values.

Fig. 2 .

 2 Fig. 2. Jitter boxplots for δ 13 C values of the ungulates from the Plio-Pleistocene site of AaO. Boxes = first and third quartile for each taxon, whiskers = full range for each taxon and hashes within boxes = median value.

Fig. 3 .

 3 Fig. 3. Jitter boxplots for δ 18 O values of the ungulates from the Plio-Pleistocene site of AaO. Boxes = first and third quartile for each taxon, whiskers = full range for each taxon and hashes within boxes = median value.

Fig. 4 .

 4 Fig. 4. Jitter boxplot with mesowear scores (MWS) of the ungulates from AaO. Boxes = first and third quartile for each taxon; whiskers = full range for each taxon and hashes within boxes = median value.

  species analyzed are classified into two groups. The first group includes the S. maurusium and Gazella sp. and plot among extant browser ungulates. The second group, which includes Alcelaphini, H. pomeli, M. phacochoeroides and A. osiris, plot among extant mixed feeders. The first group has microwear patterns characterized by a high number of pits (NP = 24.1) and a small number of scratches (NS = 11.2) and the second group has a microwear pattern defined by a similar number of pits (NP = 21.9) and scratches (NS = 21.6). Gazella sp. (NS = 9.5) and S. maurusium (NS = 12.8) are the species with a lower number of scratches, and H. pomeli (NS = 20.6) and A. osiris (NS = 26) have a higher number of scratches. All species have a similar and a relatively high number of pits. The A. osiris (NP = 25.5) and S. maurisium (NP = 9.5) have the highest abundance of pits. Although the Alcelaphini, H. pomeli, M. phacochoeroides and A. osiris in Figure 5 are classified among extant mixed feeders, the high number of scratches (see Table

Fig. 5 .

 5 Fig. 5. Bivariate plot of the average numbers of pits and scratches for the species from AaO. Error bars correspond to standard deviation (± 1 SD) for the fossil samples. Plain ellipses correspond to the Gaussian confidence ellipses (p = 0.95) on the centroid for the extant browsers and grazers based on the database from Solounias and Semprebon (2002).

  Abbreviations: B = browser, MF-B = browsing-dominated mixed feeder, MF = mixed feeder, MF-G = grass-dominated mixed feeder, and G = grazer. The parentheses indicate the consumption of C 4 plants (in very low percentage) in some species.

  3 (~3 Ma), Alcelaphini (Parmularius, Damaliscus and Connochaetes) have C 4 values, in contrast to the Tragelaphini from the same level, which have a clear C 3 values.

  Tunisia, Aïn el Bey, Aïn el Hadj Baba, Aïn Jourdel, Mansourah, Aïn Boucherit, Aïn Hanech, Puits Carouby, Carrière Brunie, Carrières Quartier St-Pierre in Algeria, and Fouarat, Oued Akrech, and Guefaït in Morocco. The dating of the youngest North African hipparion record occurs at Aïn Hanech (~1.7 Ma) (Van der Made et al., 2022).

the

  Plio-Pleistocene boundary in the western coastal region of Morocco, open C 3 grasslands and shrubland predominated in an arid climate.The most notable distinction between taxa from East, South, and Central Africa in comparison to those from the North is their extensive reliance on C 4 plants, which are associated with tropical grasses from open arid habitats. In the AaO area, although there was a consumption of C 3 plants, the environment was similarly arid and characterized by open grasslands. This aridity was also evident in Tighenif, even with the presence of hominins in the region. Therefore, the dry environment should not have been a limitation to hominins occupation in North Africa. Despite AaO being one of the most abundant fossil fauna sites in North Africa during the Plio-Pleistocene, taxon diversity remains relatively low compared to contemporary sites in the East and South. This could be attributed to the limited diversity of habitats in AaO, such as the absence of woody vegetation or, for instance, the possible lack of permanent water sources, as indicated by the absence of taxa like Hippopotamidae, crocodiles, or freshwater birds(Geraads et al., 2022).However, further research in different archaeological and palaeontological sites from the Early Pleistocene and Late Pliocene in the Maghreb is necessary to gain a holistic understanding of the ecological and climatic dynamics that contributed to the dispersal, occupation, and evolution of mammals and early hominins.CRediT author statementIván Ramírez-Pedraza: Conceptualization, Formal analysis, Visualization, Investigation and Writing -Original Draft; Florent Rivals: Supervision and Writing -Review & Editing; Carlos Tornero: Supervision and Writing -Review & Editing; Denis Geraads: Writing -Review & Editing; Jean Paul Raynal: Writing -Review & Editing; David Lefèvre: Project administration and Writing -Review & Editing; Abderrahim Mohib: Project administration, Resources and Writing -Review & Editing.

Table 2 )

 2 . The sensitivity of cusp sharpness to ontogenetic age has been documented for

	both young and old individuals. Conversely, mesowear displays a weaker correlation
	with age in intermediate age groups, and demonstrates a stronger relationship with
	dietary factors

Table 2

 2

)

[START_REF] El-Zaatari | Occlusal microwear texture analysis and the diets of historical/prehistoric hunter-gatherers[END_REF][START_REF] King | Effect of taphonomic processes on dental microwear[END_REF]

. Examination of enamel microwear features was conducted through standard light microscopy, using a Zeiss Stemi 2000C stereomicroscope at a magnification of 35x on high-resolution epoxy casts of the teeth. The cleaning, molding, casting, and examination protocols, as well as feature classification criteria, were consistent with those established by

[START_REF] Solounias | Advances in the Reconstruction of Ungulate Ecomorphology with Application to Early Fossil Equids[END_REF]

and

[START_REF] Semprebon | Can low-magnification stereomicroscopy reveal diet?[END_REF]

. Upper and lower teeth, spanning from P4 to M3, were included in the analysis following

[START_REF] Xafis | Which tooth to sample? A methodological study of the utility of premolar/non-carnassial teeth in the microwear analysis of mammals[END_REF]

. The occlusal surface of each specimen was first cleaned with acetone and 96% ethanol before being molded with high-resolution silicone (Heraeus Kulzer, PROVIL novo Vinylpolysiloxane, Light C.D. 2 regular set) and transparent casts were created using clear epoxy resin (C.T.S. Spain, EPO 150 + K151

Table 1 )

 1 . The MAP results are estimated in Table1. In order to calculate it, the five individuals with C 4 presence have been excluded based on the criteria established by[START_REF] Kohn | Carbon isotope compositions of terrestrial C 3 plants as indicators of (paleo)ecology and (paleo)climate[END_REF].

	The

Table 1 ; Supplementary Table 1

 1

Table 1 .

 1 Summary of δ 13 C (‰), Body Mass (Kg), ɛ* enamel-diet (‰), δ 13 C diet-meq (‰), %C 4 and

	Mean

4.1.3 Obligate drinkers vs. non-Obligate drinkers taxa

The ANOVA statistical test and Tukey's pairwise comparison show significant differences in the δ 18 O enamel values among the obligate drinkers (n = 17; A. osiris and H.

Table 2 .

 2 Summary of mesowear and microwear data of the fossil assemblages from AaO. Abbreviations: %G, percentage of specimens with gouges; %XS, percentage of specimens with cross scratches; %0-17, percentage of specimens with number of scratches ranging between 0 and 17.

	Species	n	δ 13 C (‰)	Body Mass	ɛ* enamel-diet (‰) δ 13 C diet-meq (‰)	%C 4	MAP (mm/yr)
				(Kg)
	S. maurusium	6 -12.4 ± 1.4	1236	+14	-27.9 ± 1.4	0	1041 ± 760
	Alcelaphini	18 -10.3 ± 1.3	200	+13.2	-23.9 ± 1.3	1.5 ± 3.2	177 ± 210
	Gazella sp.	18 -11.6 ± 0.6	30	+12.4	-24.1 ± 0.6	0	139 ± 112
	H. pomeli	16 -11.7 ± 0.9	250	+13.3	-26.5 ± 0.9	0	400 ± 269
	M. phacochoeroides 23 -11.7 ± 1.2	297	+13.4	-26.5 ± 1.2	0.3 ± 1.3	455 ± 274
	A. osiris	1	-13.3	5000	+14.7	-29.6	0	1996
	All species	82 -11.4 ± 1.2	-	+13.2	-26.1 ± 1.4	0.4 ± 1.7

n, number of specimens; MWS, mesowear score; NS, average number of scratches; NP, average number of pits; SD, standard deviation; SWS, scratch width score; %PP, percentage of specimens with puncture pits; %HC, percentage of specimens with hyper-coarse scratches; %LP, percentage of specimens with

Table 3 .

 3 Summary of dietary interpretations based on tooth wear and stable carbon isotope data.

  and Makapansgat(South Africa; ~3 Ma (Lee-Thorp et al., 2010). Although this species is known from various North African sites such as Aïn Boucherit, Aïn Hanech and El-

Kherba (Early Pleistocene; Algeria), Aïn Jourdel (Late Pliocene; Algeria), and Ichkeul and Aïn Brimba (Late Pliocene; Tunisia), this is the first time that data on its diet has been obtained from this area.

  The genus Metridiochoerus first appeared in Africa ~3.5 Ma. Metridiochoerus phacochoeroides is endemic to northern Africa and is distinct from the east and South African representatives of the genus. Besides AaO, Metridiochoerus is rare in North

	The Metridiochoerus phacochoeroides from AaO shows a predominance of C 3 plant
	carbon values (mean δ 13 C = -11.7 ± 1.2‰), but with significant variability, including a
	small percentage of C 4 consumption in one individual as observed in Alcelaphini.
	Microwear analysis shows a mixed diet, although with significant consumption of
	grasses, like other species classified as mixed feeders. The combination of both proxies
	indicates a preferential diet based on C 3 grass consumption.
	Despite the low presence of C 4 plants in North Africa during the study period, some
	species in AaO show a consumption of C 4 plants, but this is not the case for H. pomeli,
	which may indicate slightly different dietary preferences compared to its relatives in
	other parts of Africa.

Acknowledgments

Excavations at Ahl al Oughlam were conducted by Denis Geraads from 1989 to 2004 in the framework of the France-Morocco "Préhistoire de Casablanca" research project, led by Jean-Paul Raynal and Fatima Zohra Sbihi-Alaoui. These excavations involved the participation of Abderrahim Mohib, Fethi Amani and many Casablanca workers, especially Abdeslam Nader, Abdelali Khadouma and Hassan Caid Rha.

Funding

The France-Morocco "Préhistoire de Casablanca" research project is jointly supported and funded by the "Institut National des Sciences de l'Archéologie et du Patrimoine" (INSAP) of the Ministère de la Jeunesse, de la Culture et de la Communication/Département de la Culture of the Kingdom of Morocco, the "Mission Littoral-Maroc" of the Ministère de l'Europe et des Affaires Étrangères of France and the LabEx ARCHIMEDE -ANR-11-LABX-0032-01. This project was also supported by the Department of Human Evolution of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, the Aquitaine Region through the "Origines" projects, the Collège de France, the Muséum National d'Histoire Naturelle in Paris, and the University of Bordeaux (France). I.R.-P. is a beneficiary of predoctoral fellowship (2020-FI-B-00731) funded by AGAUR and the Fons Social Europeu (FSE). C.T was supported by the Spanish Ministry of Science and Innovation through the "Ramón y Cajal" program (RYC2020-029404-I). The Institut Català de Paleoecologia Humana i Evolució Social (IPHES-CERCA) has received financial support from the Spanish Ministry of Science and Innovation through the "María de Maeztu" program for Units of Excellence (CEX2019-000945-M) and the 2021 SGR 01237 "Group of Analyses on Socio-ecological Processes, Cultural Changes and Population dynamics during Prehistory (GAPS)" from the Generalitat de Catalunya. Appendix A. Supplementary data