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Megalodon

Otodus megalodon (meaning "big tooth"), commonly known as megalodon, is an extinct species of giant mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Pliocene epochs. O. megalodon was formerly thought to be a member of the family Lamnidae and a close relative of the great white shark (Carcharodon carcharias), but has been reclassified into the extinct family Otodontidae, which diverged from the great white shark during the Early Cretaceous.

While regarded as one of the largest and most powerful predators to have ever lived, megalodon is only known from fragmentary remains, and its appearance and maximum size are uncertain. Scientists differ on whether it would have more closely resembled a stockier version of the great white shark (Carcharodon carcharias), the basking shark (Cetorhinus maximus) or the sand tiger shark (Carcharias taurus). The most recent estimate with the least error range suggests a maximum length estimate up to 20.3 m, although the modal lengths are estimated at 10.5 m. Their teeth were thick and robust, built for grabbing prey and breaking bone, and their large jaws could exert a bite force of up to 108,500 to 182,200 newtons.

Megalodon probably had a major impact on the structure of marine communities. The fossil record indicates that it had a cosmopolitan distribution. It probably targeted large prey, such as whales, seals and sea turtles. Juveniles inhabited warm coastal waters and fed on fish and small whales. Unlike the great white, which attacks prey from the soft underside, megalodon probably used its strong jaws to break through the chest cavity and puncture the heart and lungs of its prey.

The animal faced competition from whale-eating cetaceans, such as Livyatan and other macroraptorial sperm whales and possibly smaller ancestral killer whales (Orcinus). As the shark preferred warmer waters, it is thought that oceanic cooling associated with the onset of the ice ages, coupled with the lowering of sea levels and resulting loss of suitable nursery areas, may have also contributed to its decline. A reduction in the diversity of baleen whales and a shift in their distribution toward polar regions may have reduced megalodon's primary food source. The shark's extinction coincides with a gigantism trend in baleen whales.

Prescientific and early research history
Megalodon teeth have been excavated and used since ancient times. They were a valued artifact amongst pre-Columbian cultures in the Americas for their large sizes and serrated blades, from which they were modified into projectile points, knives, jewelry, and funeral accessories. At least some, such as the Panamanian Sitio Conte societies, seemed to have used them primarily for ceremonial purposes. Mining of megalodon teeth by the Algonquin peoples in the Chesapeake Bay and their selective trade with the Adena culture in Ohio occurred as early as 430 BC. The earliest written account of megalodon teeth was by Pliny the Elder in an AD 73 volume of Historia Naturalis, who described them as resembling petrified human tongues that Roman folklorists believed to have fallen from the sky during lunar eclipses and called them glossopetrae ("tongue stones"). The purported tongues were later thought in a 12th-century Maltese tradition to have belonged to serpents that Paul the Apostle turned to stone while shipwrecked there, and were given antivenom powers by the saint. Glossopetrae reappeared throughout Europe in late 13th to 16th century literature, ascribed with more supernatural properties that cured a wider variety of poisons. Use of megalodon teeth for this purpose became widespread among medieval and Renaissance nobility, who fashioned them into protective amulets and tableware to purportedly detoxify poisoned liquids or bodies that touched the stones. By the 16th century, teeth were directly consumed as ingredients of European-made Goa stones.

The true nature of the glossopetrae as shark's teeth was held by some since at least 1554, when cosmographer André Thevet described it as hearsay, although he did not believe it. The earliest scientific argument for this view was made by Italian naturalist Fabio Colonna, who in 1616 published an illustration of a Maltese megalodon tooth alongside a great white shark's and noted their striking similarities. He argued that the former and its likenesses were not petrified serpent's tongues but actually the teeth of similar sharks that washed up on shore. Colonna supported this thesis through an experiment of burning glossopetrae samples, from which he observed carbon residue he interpreted as proving an organic origin. However, interpretation of the stones as shark's teeth remained widely unaccepted. This was in part due the inability to explain how some of them are found far from the sea. The shark tooth argument was academically raised again during the late 17th century by English scientists Robert Hooke, John Ray, and Danish naturalist Niels Steensen (Latinized Nicholas Steno). Steensen's argument in particular is most recognized as inferred from his dissection of the head of a great white caught in 1666. His 1667 report depicted engravings of a shark's head and megalodon teeth that became especially iconic. However, the illustrated head was not actually the head that Steensen dissected, nor were the fossil teeth illustrated by him. Both engravings were originally commissioned in the 1590s by Papal physician Michele Mercati, who also had in possession the head of a great white, for his book Metallotheca. The work remained unpublished in Steensen's time due to Mercati's premature death, and the former reused the two illustrations per suggestion by Carlo Roberto Dati, who thought a depiction of the actual dissected shark was unsuitable for readers. Steensen also stood out in pioneering a stratigraphic explanation for how similar stones appeared further inland. He observed that rock layers bearing megalodon teeth contained marine sediments and hypothesized that these layers correlated to a period of flood that was later covered by terrestrial layers and uplifted by geologic activity.

Swiss naturalist Louis Agassiz gave megalodon its scientific name in his seminal 1833-1843 work Recherches sur les poissons fossiles (Research on fossil fish). He named it Carcharias megalodon in an 1835 illustration of the holotype and additional teeth, congeneric with the modern sand tiger shark. The specific name is a portmanteau of the Ancient Greek words μεγάλος (megálos, meaning "big") and ὀδών (odṓn, meaning "tooth"), combined meaning "big tooth." Agassiz referenced the name as early as 1832, but because specimens were not referenced they are not taxonomically recognized uses. Formal description of the species was published in an 1843 volume, where Agassiz revised the name to Carcharodon megalodon as its teeth were far too large for the former genus and more alike to the great white shark. He also erroneously identified several megalodon teeth as belonging to additional species eventually named Carcharodon rectidens, Carcharodon subauriculatus, Carcharodon productus, and Carcharodon polygurus. Because Carcharodon megalodon appeared first in the 1835 illustration, the remaining names are considered junior synonyms under the principle of priority.

Evolution

While the earliest megalodon remains have been reported from the Late Oligocene, around 28 million years ago (Mya), there is disagreement as to when it appeared, with dates ranging to as young as 16 mya. It has been thought that megalodon became extinct around the end of the Pliocene, about 2.6 Mya; claims of Pleistocene megalodon teeth, younger than 2.6 million years old, are considered unreliable. A 2019 assessment moves the extinction date back to earlier in the Pliocene, 3.6 Mya.

Megalodon is considered to be a member of the family Otodontidae, genus Otodus, as opposed to its previous classification into Lamnidae, genus Carcharodon. Megalodon's classification into Carcharodon was due to dental similarity with the great white shark, but most authors believe that this is due to convergent evolution. In this model, the great white shark is more closely related to the extinct broad-toothed mako (Isurus hastalis) than to megalodon, as evidenced by more similar dentition in those two sharks; megalodon teeth have much finer serrations than great white shark teeth. The great white shark is more closely related to the mako sharks (Isurus spp.), with a common ancestor around 4 Mya. Proponents of the former model, wherein megalodon and the great white shark are more closely related, argue that the differences between their dentition are minute and obscure.

The genus Carcharocles contains four species: C. auriculatus, C. angustidens, C. chubutensis, and C. megalodon. The evolution of this lineage is characterized by the increase of serrations, the widening of the crown, the development of a more triangular shape, and the disappearance of the lateral cusps. The evolution in tooth morphology reflects a shift in predation tactics from a tearing-grasping bite to a cutting bite, likely reflecting a shift in prey choice from fish to cetaceans. Lateral cusplets were finally lost in a gradual process that took roughly 12 million years during the transition between C. chubutensis and C. megalodon. The genus was proposed by D. S. Jordan and H. Hannibal in 1923 to contain C. auriculatus. In the 1980s, megalodon was assigned to Carcharocles. Before this, in 1960, the genus Procarcharodon was erected by French ichthyologist Edgard Casier, which included those four sharks and was considered separate from the great white shark. It is since considered a junior synonym of Carcharocles. The genus Palaeocarcharodon was erected alongside Procarcharodon to represent the beginning of the lineage, and, in the model wherein megalodon and the great white shark are closely related, their last common ancestor. It is believed to be an evolutionary dead-end and unrelated to the Carcharocles sharks by authors who reject that model.

Another model of the evolution of this genus, also proposed by Casier in 1960, is that the direct ancestor of the Carcharocles is the shark Otodus obliquus, which lived from the Paleocene through the Miocene epochs, 60 to 13 Mya. The genus Otodus is ultimately derived from Cretolamna, a shark from the Cretaceous period. In this model, O. obliquus evolved into O. aksuaticus, which evolved into C. auriculatus, and then into C. angustidens, and then into C. chubutensis, and then finally into C. megalodon.

Another model of the evolution of Carcharocles, proposed in 2001 by paleontologist Michael Benton, is that the three other species are actually a single species of shark that gradually changed over time between the Paleocene and the Pliocene, making it a chronospecies. Some authors suggest that C. auriculatus, C. angustidens, and C. chubutensis should be classified as a single species in the genus Otodus, leaving C. megalodon the sole member of Carcharocles.

The genus Carcharocles may be invalid, and the shark may actually belong in the genus Otodus, making it Otodus megalodon. A 1974 study on Paleogene sharks by Henri Cappetta erected the subgenus Megaselachus, classifying the shark as Otodus (Megaselachus) megalodon, along with O. (M.) chubutensis. A 2006 review of Chondrichthyes elevated Megaselachus to genus, and classified the sharks as Megaselachus megalodon and M. chubutensis. The discovery of fossils assigned to the genus Megalolamna in 2016 led to a re-evaluation of Otodus, which concluded that it is paraphyletic, that is, it consists of a last common ancestor but it does not include all of its descendants. The inclusion of the Carcharocles sharks in Otodus would make it monophyletic, with the sister clade being Megalolamna.

The cladogram below represents the hypothetical relationships between megalodon and other sharks, including the great white shark. Modified from Shimada et al. (2016), Ehret et al., (2009), and the findings of Siversson et al. (2015).

Appearance
One interpretation on how megalodon appeared was that it was a robust-looking shark, and may have had a similar build to the great white shark. The jaws may have been blunter and wider than the great white, and the fins would have also been similar in shape, though thicker due to its size. It may have had a pig-eyed appearance, in that it had small, deep-set eyes.

Another interpretation is that megalodon bore a similarity to the whale shark (Rhincodon typus) or the basking shark (Cetorhinus maximus). The tail fin would have been crescent-shaped, the anal fin and second dorsal fin would have been small, and there would have been a caudal keel present on either side of the tail fin (on the caudal peduncle). This build is common in other large aquatic animals, such as whales, tuna, and other sharks, in order to reduce drag while swimming. The head shape can vary between species as most of the drag-reducing adaptations are toward the tail-end of the animal.

One associated set of megalodon remains was found with placoid scales, which are 0.3 to 0.8 mm in maximum width, and have broadly spaced keels.

Size
Due to fragmentary remains, there have been many contradictory size estimates for megalodon, as they can only be drawn from fossil teeth and vertebrae. The great white shark has been the basis of reconstruction and size estimation, as it is regarded as the best analogue to megalodon. Several total length estimation methods have been produced from comparing megalodon teeth and vertebrae to those of the great white.

Megalodon size estimates vary depending on the method used, with maximum total length estimates ranging from 14.2 - 20.3 m.  A 2015 study estimated the average total body length at 10.5 m, calculated from 544 megalodon teeth, found throughout geological time and geography, including adults and juveniles. In comparison, large great white sharks are generally around 6 m in length, with a few contentious reports suggesting larger sizes. The whale shark is the largest living fish, with one large female reported with a precaudal length of 15 m and an estimated total length of 18.8 m. It is possible that different populations of megalodon around the globe had different body sizes and behaviors due to different ecological pressures. Megalodon is thought to have been the largest macropredatory shark that ever lived.

"'A C. megalodon about 16 meters long would have weighed about 48 metric tons (53 tons). A 17-meter (56-foot) C. megalodon would have weighed about 59 metric tons (65 tons), and a 20.3-meter (67 foot) monster would have topped off at 103 metric tons (114 tons).'"

In his 2015 book, The Story of Life in 25 Fossils: Tales of Intrepid Fossil Hunters and the Wonders of Evolution, Donald Prothero proposed the body mass estimates for different individuals of different length by extrapolating from a vertebral centra based on the dimensions of the great white, a methodology also used for the 2008 study which supports the maximum mass estimate.

In 2020, Cooper and his colleagues reconstructed a 2D model of megalodon based on the dimensions of all the extant lamnid sharks and suggested that a 16 m long megalodon would have had a 4.65 m long head, 1.41 m tall gill slits, a 1.62 m tall dorsal fin, 3.08 m long pectoral fins, and a 3.85 m tall tail fin. In 2022, Cooper and his colleagues also reconstructed a 3D model with the same basis as the 2020 study, resulting in a body mass estimate of 61.56 t for a 16 m long megalodon (higher than the previous estimates); a vertebral column specimen named IRSNB P 9893 (formerly IRSNB 3121), belonging to a 46 year old individual from Belgium, was used for extrapolation. An individual of this size would have required 98,175 kcal per day, 20 times more than what the adult great white requires.

Mature male megalodon may have had a body mass of 12.6 to 33.9 t, and mature females may have been 27.4 to 59.4 t, assuming that males could range in length from 10.5 to 14.3 m and females 13.3 to 17 m.

A 2015 study linking shark size and typical swimming speed estimated that megalodon would have typically swum at 18 kph–assuming that its body mass was typically 48 t–which is consistent with other aquatic creatures of its size, such as the fin whale (Balaenoptera physalus) which typically cruises at speeds of 14.5 to 21.5 kph. In 2022, Cooper and his colleagues converted this calculation into relative cruising speed (body lengths per second), resulting in an mean absolute cruising speed of 5 kph and a mean relative cruising speed of 0.09 body lengths per second for a 16 m long megalodon; the authors found their mean absolute cruising speed to be faster than any extant lamnid sharks and their mean relative cruising speed to be slower, consistent with previous estimates. Its large size may have been due to climatic factors and the abundance of large prey items, and it may have also been influenced by the evolution of regional endothermy (mesothermy) which would have increased its metabolic rate and swimming speed. The otodontid sharks have been considered to have been ectotherms, so on that basis megalodon would have been ectothermic. However, the largest contemporary ectothermic sharks, such as the whale shark, are filter feeders, while lamnids are regional endotherms, implying some metabolic correlations with a predatory lifestyle. These considerations, as well as tooth oxygen isotopic data and the need for higher burst swimming speeds in macropredators of endothermic prey than ectothermy would allow, imply that otodontids, including megalodon, were probably regional endotherms.

In 2020, Shimada and colleagues suggested large size was instead due to intrauterine cannibalism, where the larger fetus eats the smaller fetus, resulting in progressively larger and larger fetuses, requiring the mother to attain even greater size as well as caloric requirements which would have promoted endothermy. Males would have needed to keep up with female size in order to still effectively copulate (which probably involved latching onto the female with claspers, like modern cartilaginous fish).

Maximum estimates
The first attempt to reconstruct the jaw of megalodon was made by Bashford Dean in 1909, displayed at the American Museum of Natural History. From the dimensions of this jaw reconstruction, it was hypothesized that megalodon could have approached 30 m in length. Dean had overestimated the size of the cartilage on both jaws, causing it to be too tall.

In 1973, John E. Randall, an ichthyologist, used the enamel height (the vertical distance of the blade from the base of the enamel portion of the tooth to its tip) to measure the length of the shark, yielding a maximum length of about 13 m. However, tooth enamel height does not necessarily increase in proportion to the animal's total length.

In 1994, marine biologists Patrick J. Schembri and Stephen Papson opined that O. megalodon may have approached a maximum of around 24 to 25 m in total length.

In 1996, shark researchers Michael D. Gottfried, Leonard Compagno, and S. Curtis Bowman proposed a linear relationship between the great white shark's total length and the height of the largest upper anterior tooth. The proposed relationship is: total length in meters = − (0.096) × [UA maximum height (mm)]-(0.22). Using this tooth height regression equation, the authors estimated a total length of 15.9 m based on a tooth 16.8 cm tall, which the authors considered a conservative maximum estimate. They also compared the ratio between the tooth height and total length of large female great whites to the largest megalodon tooth. A 6 m long female great white, which the authors considered the largest 'reasonably trustworthy' total length, produced an estimate of 16.8 m. However, based on the largest female great white reported, at 7.1 m, they estimated a maximum estimate of 20.2 m.

In 2002, shark researcher Clifford Jeremiah proposed that total length was proportional to the root width of an upper anterior tooth. He claimed that for every 1 cm of root width, there are approximately 1.4 m of shark length. Jeremiah pointed out that the jaw perimeter of a shark is directly proportional to its total length, with the width of the roots of the largest teeth being a tool for estimating jaw perimeter. The largest tooth in Jeremiah's possession had a root width of about 12 cm, which yielded 16.5 m in total length.

In 2002, paleontologist Kenshu Shimada of DePaul University proposed a linear relationship between tooth crown height and total length after conducting anatomical analysis of several specimens, allowing any sized tooth to be used. Shimada stated that the previously proposed methods were based on a less-reliable evaluation of the dental homology between megalodon and the great white shark, and that the growth rate between the crown and root is not isometric, which he considered in his model. Using this model, the upper anterior tooth possessed by Gottfried and colleagues corresponded to a total length of 15 m. Among several specimens found in the Gatún Formation of Panama, one upper lateral tooth was used by other researchers to obtain a total length estimate of 17.9 m using this method.

In 2019, Shimada revisited the size of megalodon and discouraged using non-anterior teeth for estimations, noting that the exact position of isolated non-anterior teeth is difficult to identify. Shimada provided maximum total length estimates using the largest anterior teeth available in museums. The tooth with the tallest crown height known to Shimada, NSM PV-19896, produced a total length estimate of 14.2 m. The tooth with the tallest total height, FMNH PF 11306, was reported at 16.8 cm. However, Shimada remeasured the tooth and found it actually to measure 16.2 cm. Using the total height tooth regression equation proposed by Gottfried and colleagues produced an estimate of 15.3 m.

In 2021, Victor J. Perez, Ronny M. Leder, and Teddy Badaut proposed a method of estimating total length of megalodon from the sum of the tooth crown widths. Using more complete megalodon dentitions, they reconstructed the dental formula and then made comparisons to living sharks. The researchers noted that the 2002 Shimada crown height equations produce wildly varying results for different teeth belonging to the same shark (range of error of ± 9 m), casting doubt on some of the conclusions of previous studies using that method. Using the largest tooth available to the authors, GHC 6, with a crown width of 13.3 cm, they estimated a maximum body length of approximately 20 m, with a range of error of approximately ± 3.5 m. This maximum length estimate was also supported by Cooper and his colleagues in 2022.

There are anecdotal reports of teeth larger than those found in museum collections. Gordon Hubbell from Gainesville, Florida, possesses an upper anterior megalodon tooth whose maximum height is 7.25 in, one of the largest known tooth specimens from the shark. In addition, a 9 by megalodon jaw reconstruction developed by fossil hunter Vito Bertucci contains a tooth whose maximum height is reportedly over 18 cm.

Teeth and bite force
The most common fossils of megalodon are its teeth. Diagnostic characteristics include a triangular shape, robust structure, large size, fine serrations, a lack of lateral denticles, and a visible V-shaped neck (where the root meets the crown). The tooth met the jaw at a steep angle, similar to the great white shark. The tooth was anchored by connective tissue fibers, and the roughness of the base may have added to mechanical strength. The lingual side of the tooth, the part facing the tongue, was convex; and the labial side, the other side of the tooth, was slightly convex or flat. The anterior teeth were almost perpendicular to the jaw and symmetrical, whereas the posterior teeth were slanted and asymmetrical.

Megalodon teeth can measure over 180 mm in slant height (diagonal length) and are the largest of any known shark species, implying it was the largest of all macropredatory sharks. In 1989, a nearly complete set of megalodon teeth was discovered in Saitama, Japan. Another nearly complete associated megalodon dentition was excavated from the Yorktown Formations in the United States, and served as the basis of a jaw reconstruction of megalodon at the National Museum of Natural History (USNM). Based on these discoveries, an artificial dental formula was put together for megalodon in 1996.

The dental formula of megalodon is:. As evident from the formula, megalodon had four kinds of teeth in its jaws: anterior, intermediate, lateral, and posterior. Megalodon's intermediate tooth technically appears to be an upper anterior and is termed as "A3" because it is fairly symmetrical and does not point mesially (side of the tooth toward the midline of the jaws where the left and right jaws meet). Megalodon had a very robust dentition, and had over 250 teeth in its jaws, spanning 5 rows. It is possible that large megalodon individuals had jaws spanning roughly 2 m across. The teeth were also serrated, which would have improved efficiency in cutting through flesh or bone. The shark may have been able to open its mouth to a 75° angle, though a reconstruction at the USNM approximates a 100° angle.

In 2008, a team of scientists led by S. Wroe conducted an experiment to determine the bite force of the great white shark, using a 2.5 m long specimen, and then isometrically scaled the results for its maximum size and the conservative minimum and maximum body mass of megalodon. They placed the bite force of the latter between 108,514 to 182,201 N in a posterior bite, compared to the 18,216 N bite force for the largest confirmed great white shark, and 7,495 N for the placoderm fish Dunkleosteus. In addition, Wroe and colleagues pointed out that sharks shake sideways while feeding, amplifying the force generated, which would probably have caused the total force experienced by prey to be higher than the estimate.

In 2021, Antonio Ballell and Humberto Ferrón used Finite Element Analysis modeling to examine the stress distribution of three types of megalodon teeth and closely related mega-toothed species when exposed to anterior and lateral forces, the latter of which would be generated when a shark shakes its head to tear through flesh. The resulting simulations identified higher levels of stress in megalodon teeth under lateral force loads compared to its precursor species such as O. obliquus and O. angusteidens when tooth size was removed as a factor. This suggests that megalodon teeth were of a different functional significance than previously expected, challenging prior interpretations that megalodon's dental morphology was primarily driven by a dietary shift towards marine mammals. Instead, the authors proposed that it was a byproduct of an increase in body size caused by heterochronic selection.

Internal anatomy

Megalodon is represented in the fossil record by teeth, vertebral centra, and coprolites. As with all sharks, the skeleton of megalodon was formed of cartilage rather than bone; consequently most fossil specimens are poorly preserved. To support its large dentition, the jaws of megalodon would have been more massive, stouter, and more strongly developed than those of the great white, which possesses a comparatively gracile dentition. Its chondrocranium, the cartilaginous skull, would have had a blockier and more robust appearance than that of the great white. Its fins were proportional to its larger size.

Some fossil vertebrae have been found. The most notable example is a partially preserved vertebral column of a single specimen, excavated in the Antwerp Basin, Belgium, in 1926. It comprises 150 vertebral centra, with the centra ranging from 55 mm to 155 mm in diameter. The shark's vertebrae may have gotten much bigger, and scrutiny of the specimen revealed that it had a higher vertebral count than specimens of any known shark, possibly over 200 centra; only the great white approached it. Another partially preserved vertebral column of a megalodon was excavated from the Gram Formation in Denmark in 1983, which comprises 20 vertebral centra, with the centra ranging from 100 mm to 230 mm in diameter. The coprolite remains of megalodon are spiral-shaped, indicating that the shark may have had a spiral valve, a corkscrew-shaped portion of the lower intestines, similar to extant lamniform sharks. Miocene coprolite remains were discovered in Beaufort County, South Carolina, with one measuring 14 cm.

Gottfried and colleagues reconstructed the entire skeleton of megalodon, which was later put on display at the Calvert Marine Museum in the United States and the Iziko South African Museum. This reconstruction is 11.3 m long and represents a mature male, based on the ontogenetic changes a great white shark experiences over the course of its life.

Range and habitat
Megalodon had a cosmopolitan distribution; its fossils have been excavated from many parts of the world, including Europe, Africa, the Americas, and Australia. It most commonly occurred in subtropical to temperate latitudes. It has been found at latitudes up to 55° N; its inferred tolerated temperature range was 1 –. It arguably had the capacity to endure such low temperatures due to mesothermy, the physiological capability of large sharks to maintain a higher body temperature than the surrounding water by conserving metabolic heat.

Megalodon inhabited a wide range of marine environments (i.e., shallow coastal waters, areas of coastal upwelling, swampy coastal lagoons, sandy littorals, and offshore deep water environments), and exhibited a transient lifestyle. Adult megalodon were not abundant in shallow water environments, and mostly inhabited offshore areas. Megalodon may have moved between coastal and oceanic waters, particularly in different stages of its life cycle.

Fossil remains show a trend for specimens to be larger on average in the Southern Hemisphere than in the Northern, with mean lengths of 11.6 and 9.6 m, respectively; and also larger in the Pacific than the Atlantic, with mean lengths of 10.9 and 9.5 m respectively. They do not suggest any trend of changing body size with absolute latitude, or of change in size over time (although the Carcharocles lineage in general is thought to display a trend of increasing size over time). The overall modal length has been estimated at 10.5 m, with the length distribution skewed towards larger individuals, suggesting an ecological or competitive advantage for larger body size.

Locations of fossils
Megalodon had a global distribution and fossils of the shark have been found in many places around the world, bordering all oceans of the Neogene.

Prey relationships
Though sharks are generally opportunistic feeders, megalodon's great size, high-speed swimming capability, and powerful jaws, coupled with an impressive feeding apparatus, made it an apex predator capable of consuming a broad spectrum of animals. Otodus megalodon was probably one of the most powerful predators to have existed. A study focusing on calcium isotopes of extinct and extant elasmobranch sharks and rays revealed that megalodon fed at a higher trophic level than the contemporaneous great white shark ("higher up" in the food chain).

Fossil evidence indicates that megalodon preyed upon many cetacean species, such as dolphins, small whales, cetotheres, squalodontids (shark toothed dolphins), sperm whales, bowhead whales, and rorquals. In addition to this, they also targeted seals, sirenians, and sea turtles. The shark was an opportunist and piscivorous, and it would have also gone after smaller fish and other sharks. Many whale bones have been found with deep gashes most likely made by their teeth. Various excavations have revealed megalodon teeth lying close to the chewed remains of whales, and sometimes in direct association with them.

The feeding ecology of megalodon appears to have varied with age and between sites, like the modern great white shark. It is plausible that the adult megalodon population off the coast of Peru targeted primarily cetothere whales 2.5 to 7 m in length and other prey smaller than itself, rather than large whales in the same size class as themselves. Meanwhile, juveniles likely had a diet that consisted more of fish.

Competition
Megalodon faced a highly competitive environment. Its position at the top of the food chain probably had a significant impact on the structuring of marine communities. Fossil evidence indicates a correlation between megalodon and the emergence and diversification of cetaceans and other marine mammals. Juvenile megalodon preferred habitats where small cetaceans were abundant, and adult megalodon preferred habitats where large cetaceans were abundant. Such preferences may have developed shortly after they appeared in the Oligocene.

Megalodon were contemporaneous with whale-eating toothed whales (particularly macroraptorial sperm whales and squalodontidae), which were also probably among the era's apex predators, and provided competition. Some attained gigantic sizes, such as Livyatan, estimated between 13.5 to 17.5 m. Fossilized teeth of an undetermined species of such physeteroids from Lee Creek Mine, North Carolina, indicate it had a maximum body length of 8 to 10 m and a maximum lifespan of about 25 years. This is very different from similarly sized modern killer whales that live to 65 years, suggesting that unlike the latter, which are apex predators, these physeteroids were subject to predation from larger species such as megalodon or Livyatan. By the Late Miocene, around 11 Mya, macroraptorials experienced a significant decline in abundance and diversity. Other species may have filled this niche in the Pliocene, such as the fossil killer whale Orcinus citoniensis which may have been a pack predator and targeted prey larger than itself,  but this inference is disputed, and it was probably a generalist predator rather than a marine mammal specialist.

Megalodon may have subjected contemporaneous white sharks to competitive exclusion, as the fossil records indicate that other shark species avoided regions it inhabited by mainly keeping to the colder waters of the time. In areas where their ranges seemed to have overlapped, such as in Pliocene Baja California, it is possible that megalodon and the great white shark occupied the area at different times of the year while following different migratory prey. Megalodon probably also had a tendency for cannibalism, much like contemporary sharks.

Feeding strategies
Sharks often employ complex hunting strategies to engage large prey animals. Great white shark hunting strategies may be similar to how megalodon hunted its large prey. Megalodon bite marks on whale fossils suggest that it employed different hunting strategies against large prey than the great white shark.

One particular specimen–the remains of a 9 m long undescribed Miocene baleen whale–provided the first opportunity to quantitatively analyze its attack behavior. Unlike great whites which target the underbelly of their prey, megalodon probably targeted the heart and lungs, with their thick teeth adapted for biting through tough bone, as indicated by bite marks inflicted to the rib cage and other tough bony areas on whale remains. Furthermore, attack patterns could differ for prey of different sizes. Fossil remains of some small cetaceans, for example cetotheres, suggest that they were rammed with great force from below before being killed and eaten, based on compression fractures.

There is also evidence that a possible separate hunting strategy existed for attacking raptorial sperm whales; a tooth belonging to an undetermined 4 m physeteroid closely resembling those of Acrophyseter discovered in the Nutrien Aurora Phosphate Mine in North Carolina suggests that a megalodon or O. chubutensis may have aimed for the head of the sperm whale in order to inflict a fatal bite, the resulting attack leaving distinctive bite marks on the tooth. While scavenging behavior cannot be ruled out as a possibility, the placement of the bite marks is more consistent with predatory attacks than feeding by scavenging, as the jaw is not a particularly nutritious area to for a shark feed or focus on. The fact that the bite marks were found on the tooth's roots further suggest that the shark broke the whale's jaw during the bite, suggesting the bite was extremely powerful. The fossil is also notable as it stands as the first known instance of an antagonistic interaction between a sperm whale and an otodontid shark recorded in the fossil record.

During the Pliocene, larger cetaceans appeared. Megalodon apparently further refined its hunting strategies to cope with these large whales. Numerous fossilized flipper bones and tail vertebrae of large whales from the Pliocene have been found with megalodon bite marks, which suggests that megalodon would immobilize a large whale before killing and feeding on it.

Growth and reproduction
In 2010, Ehret estimated that megalodon had a fast growth rate nearly two times that of the extant great white shark. He also estimated that the slowing or cessation of somatic growth in megalodon occurred around 25 years of age, suggesting that this species had an extremely delayed sexual maturity. In 2021, Shimada and colleagues calculated the growth rate of an approximately 9.2 m individual based on the Belgian vertebrate column specimen that presumably contains annual growth rings on three of its vertebrae. They estimated the individual died at 46 years of age, with a growth rate of 16 cm per year, and a length of 2 m at birth. For a 15 m individual – which they considered to have been the maximum size attainable – this would equate to a lifespan of 88 to 100 years. However, Cooper and his colleagues in 2022 estimated the length of this 46 year old individual at nearly 16 m based on the 3D reconstruction which resulted in the complete vertebral column to be 11.1 m long; the researchers claimed that this size estimate difference occurred due to the fact that Shimada and his colleagues extrapolated its size only based on the vertebral centra.

Megalodon, like contemporaneous sharks, made use of nursery areas to birth their young in, specifically warm-water coastal environments with large amounts of food and protection from predators. Nursery sites were identified in the Gatún Formation of Panama, the Calvert Formation of Maryland, Banco de Concepción in the Canary Islands, and the Bone Valley Formation of Florida. Given that all extant lamniform sharks give birth to live young, this is believed to have been true of megalodon also. Infant megalodons were around 3.5 m at their smallest, and the pups were vulnerable to predation by other shark species, such as the great hammerhead shark (Sphyrna mokarran) and the snaggletooth shark (Hemipristis serra). Their dietary preferences display an ontogenetic shift: Young megalodon commonly preyed on fish, sea turtles, dugongs,  and small cetaceans; mature megalodon moved to off-shore areas and consumed large cetaceans.

An exceptional case in the fossil record suggests that juvenile megalodon may have occasionally attacked much larger balaenopterid whales. Three tooth marks apparently from a 4 to 7 m long Pliocene shark were found on a rib from an ancestral blue or humpback whale that showed evidence of subsequent healing, which is suspected to have been inflicted by a juvenile megalodon.

Climate change
The Earth experienced a number of changes during the time period megalodon existed which affected marine life. A cooling trend starting in the Oligocene 35 Mya ultimately led to glaciation at the poles. Geological events changed currents and precipitation; among these were the closure of the Central American Seaway and changes in the Tethys Ocean, contributing to the cooling of the oceans. The stalling of the Gulf Stream prevented nutrient-rich water from reaching major marine ecosystems, which may have negatively affected its food sources. The largest fluctuation of sea levels in the Cenozoic era occurred in the Plio-Pleistocene, between around 5 million to 12 thousand years ago, due to the expansion of glaciers at the poles, which negatively impacted coastal environments, and may have contributed to its extinction along with those of several other marine megafaunal species. These oceanographic changes, in particular the sea level drops, may have restricted many of the suitable shallow warm-water nursery sites for megalodon, hindering reproduction. Nursery areas are pivotal for the survival of many shark species, in part because they protect juveniles from predation.

As its range did not apparently extend into colder waters, megalodon may not have been able to retain a significant amount of metabolic heat, so its range was restricted to shrinking warmer waters. Fossil evidence confirms the absence of megalodon in regions around the world where water temperatures had significantly declined during the Pliocene. However, an analysis of the distribution of megalodon over time suggests that temperature change did not play a direct role in its extinction. Its distribution during the Miocene and Pliocene did not correlate with warming and cooling trends; while abundance and distribution declined during the Pliocene, megalodon did show a capacity to inhabit colder latitudes. It was found in locations with a mean temperature ranging from 12 to 27 C, with a total range of 1 to 33 C, indicating that the global extent of suitable habitat should not have been greatly affected by the temperature changes that occurred. This is consistent with evidence that it was a mesotherm.

Changing ecosystem
Marine mammals attained their greatest diversity during the Miocene, such as with baleen whales with over 20 recognized Miocene genera in comparison to only six extant genera. Such diversity presented an ideal setting to support a super-predator such as megalodon. By the end of the Miocene, many species of mysticetes had gone extinct; surviving species may have been faster swimmers and thus more elusive prey. Furthermore, after the closure of the Central American Seaway, tropical whales decreased in diversity and abundance. The extinction of megalodon correlates with the decline of many small mysticete lineages, and it is possible that it was quite dependent on them as a food source. Additionally, a marine megafauna extinction during the Pliocene was discovered to have eliminated 36% of all large marine species including 55% of marine mammals, 35% of seabirds, 9% of sharks, and 43% of sea turtles. The extinction was selective for endotherms and mesotherms relative to poikilotherms, implying causation by a decreased food supply and thus consistent with megalodon being mesothermic. Megalodon may have been too large to sustain itself on the declining marine food resources. The cooling of the oceans during the Pliocene might have restricted the access of megalodon to the polar regions, depriving it of the large whales which had migrated there.

Competition from large odontocetes, such as macropredatory sperm whales which appeared in the Miocene, and a member of genus Orcinus (i.e., Orcinus citoniensis) in the Pliocene, is assumed to have contributed to the decline and extinction of megalodon. But this assumption is disputed: The Orcininae emerged in Mid-Pliocene with O. citoniensis reported from the Pliocene of Italy, and similar forms reported from the Pliocene of England and South Africa, indicating the capacity of these dolphins to cope with increasingly prevalent cold water temperatures in high latitudes. These dolphins were assumed to have been macrophagous in some studies, but on closer inspection, these dolphins are not found to be macrophagous and fed on small fishes instead. On the other hand, gigantic macropredatory sperm whales such as Livyatan-like forms are last reported from Australia and South Africa circa 5 million years ago. Others, such as Hoplocetus and Scaldicetus also occupied a niche similar to that of modern killer whales but the last of these forms disappeared during the Pliocene. Members of genus Orcinus became large and macrophagous in the Pleistocene.

Paleontologist Robert Boessenecker and his colleagues rechecked the fossil record of megalodon for carbon dating errors and concluded that it disappeared circa 3.5 million years ago. Boessenecker and his colleagues further suggest that megalodon suffered range fragmentation due to climatic shifts, and competition with white sharks might have contributed to its decline and extinction. Competition with white sharks is assumed to be a factor in other studies as well, but this hypothesis warrants further testing. Multiple compounding environmental and ecological factors including climate change and thermal limitations, collapse of prey populations and resource competition with white sharks are believed to have contributed to decline and extinction of megalodon.

The extinction of megalodon set the stage for further changes in marine communities. The average body size of baleen whales increased significantly after its disappearance, although possibly due to other, climate-related, causes. Conversely the increase in baleen whale size may have contributed to the extinction of megalodon, as they may have preferred to go after smaller whales; bite marks on large whale species may have come from scavenging sharks. Megalodon may have simply become coextinct with smaller whale species, such as Piscobalaena nana. The extinction of megalodon had a positive impact on other apex predators of the time, such as the great white shark, in some cases spreading to regions where megalodon became absent.

In popular culture

Megalodon has been portrayed in many works of fiction, including films and novels, and continues to be a popular subject for fiction involving sea monsters. Reports of supposedly fresh megalodon teeth, such as those found by HMS Challenger (1858) in 1873 which were dated in 1959 by the zoologist Wladimir Tschernezky to be around 11,000 to 24,000 years old, helped popularise claims of recent megalodon survival amongst cryptozoologists. These claims have been discredited, and are probably teeth that were well-preserved by a thick mineral-crust precipitate of manganese dioxide, and so had a lower decomposition rate and retained a white color during fossilization. Fossil megalodon teeth can vary in color from off-white to dark browns, greys, and blues, and some fossil teeth may have been redeposited into a younger stratum. The claims that megalodon could remain elusive in the depths, similar to the megamouth shark which was discovered in 1976, are unlikely as the shark lived in warm coastal waters and probably could not survive in the cold and nutrient-poor deep sea environment.

Contemporary fiction about megalodon surviving into modern times was pioneered by the 1997 novel Meg: A Novel of Deep Terror by Steve Alten and its subsequent sequels. Megalodon subsequently began to feature in films, such as the 2002 direct to video Shark Attack 3: Megalodon, and later The Meg, a 2018 film based on the 1997 book which grossed over $500 million at the box office.

Animal Planet's pseudo-documentary Mermaids: The Body Found included an encounter 1.6 mya between a pod of mermaids and a megalodon. Later, in August 2013, the Discovery Channel opened its annual Shark Week series with another film for television, Megalodon: The Monster Shark Lives, a controversial docufiction about the creature that presented alleged evidence in order to suggest that megalodons still lived. This program received criticism for being completely fictional and for inadequately disclosing its fictional nature; for example, all of the supposed scientists depicted were paid actors, and there was no disclosure in the documentary itself that it was fictional. In a poll by Discovery, 73% of the viewers of the documentary thought that megalodon was not extinct. In 2014, Discovery re-aired The Monster Shark Lives, along with a new one-hour program, Megalodon: The New Evidence, and an additional fictionalized program entitled Shark of Darkness: Wrath of Submarine, resulting in further backlash from media sources and the scientific community. Despite the criticism from scientists, Megalodon: The Monster Shark Lives was a huge ratings success, gaining 4.8 million viewers, the most for any Shark Week episode up to that point.

Megalodon teeth are the state fossil of North Carolina.

title: Megalodon


text: Talk:Megalodon

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Megalodon


text:
Yorkshire Three Peaks

The mountains of Whernside (736 m), Ingleborough (723 m) and Pen-y-ghent (694 m) are collectively known as the Three Peaks. The peaks, which form part of the Pennine range, encircle the head of the valley of the River Ribble in the Yorkshire Dales National Park in the North of England.

Name
The long-standing designation "The Three Peaks" is well known locally, and in past times nationally. However, there are now a number of "National" Three Peaks adventure challenges involving Ben Nevis, Snowdon and Scafell Pike (respectively the highest summits in Scotland, Wales and England). The epithet "Yorkshire" is therefore now commonly added to differentiate Yorkshire's Three Peaks from those (although Whernside is partially in Cumbria, with the summit trig point being narrowly on the Cumbria side, the whole mountain is within the historic county of Yorkshire).

Geology
In common with neighbouring fells, the Three Peaks are carved from an almost flat-lying succession of sedimentary strata of Carboniferous age. The lower slopes of each of the fells are formed from massive limestones assigned to the Visean age Great Scar Group. The upper slopes of each of the fells are formed from alternating bands of limestone and mudstone grading up into sandstone, all of which are assigned to the Brigantian and early Namurian ages Yoredale Group. These alternations are considered to be a classic British example of cyclothems. Differential weathering and erosion of the various bands has given Ingleborough and Pen-y-ghent a distinctive, stepped appearance. The summits are capped by Grassington Grit, a variety of Millstone Grit.

Considerable areas of the flanks of each of the fells are covered by peat whilst other areas are blanketed by glacial till notably across the southern and eastern slopes of Pen-y-ghent. The Ribblehead drumlin field is considered to be one of the finest in England. Fringing Ingleborough on each side however are impressive areas of limestone pavement.

Extensive networks of caves have developed within the limestone strata such as the White Scar Caves, and potholes which attract cavers from all over the country. It is home to England's highest waterfall at Gaping Gill, where the Fell Beck drops 110 m vertically down a pothole, into Britain's second largest cavern. The beck re-emerges further down the mountain adjacent to Ingleborough Cave, where visitors can take a guided tour of a floodlit part of the cave system. Whernside, being more rounded, is visually less imposing than its neighbours, but its summit is the highest point in North Yorkshire.

History
The area is rich in historical interest. The summit of Ingleborough has the remains of a huge Iron Age hill fort, while the Settle-Carlisle Railway runs between the mountains, crossing Ribblehead Viaduct at the foot of Whernside.

Long-distance footpaths

 * The Pennine Way visits Horton and crosses the summit of Pen-y-ghent.
 * The Ribble Way follows the River Ribble from its source near the foot of Whernside to its mouth near Preston.

The Three Peaks walk
The Three Peaks walk of Pen-y-ghent, Whernside and Ingleborough is probably the original three peak walk within the UK. The first recorded ascent of the three hills was in July 1887 by J. R. Wynne-Edwards and D. R. Smith in a time of 10 hours. The walk covers a distance of 37.5 km to 42 km (depending on route) circuit of all three peaks with nearly 1600 m of ascent and descent. A challenge that many walkers aim for when undertaking the walk is to complete the walk in under 12 hours, though as Alfred Wainwright says in his book Wainwright in the Limestone Dales, "Some participants have chosen to regard the walk as a race, and this is to be greatly regretted, walking is a pleasure to be enjoyed in comfort"  (edited quote). The route most walkers take varies from the fell race in that most traverse the 'nose' of Pen-y-ghent from Brackenbottom Moor and do not ascend from the Pennine Way. Additionally, Whernside is generally traversed along the right-of-way to the east, initially following the railway line, all of which can add extra distance to the route.

For most people the route starts in the village of Horton-in-Ribblesdale, though many start from various points in the circular route, such as Chapel-le-Dale or Ribblehead Viaduct. Historically Chapel-le-Dale was the starting point though this probably changed when the Pen-y-ghent Cafe started running their clocking in and out service for walkers in 1968. The cafe is currently closed (@ March 2020) and as a result walkers can no longer register the beginning and end of their walk or pay to join the Pen-y-ghent Cafe's privately owned 'Three Peaks of Yorkshire Club'.

The Yorkshire Dales National Park runs a voluntary Friends of the Three Peaks project. The proceeds of this go towards the upkeep of the paths on the route. Certificates, medals and membership forms are awarded by local participating businesses.

The walking challenge
Understandably the Three Peaks Walk is seen by many as a challenge and it has become very popular for charity sponsored walks and Saturdays in early summer can see several hundred walkers make their way round the route.

The races
In addition to it being seen as a walking challenge it has also become a race for fell runners and cyclo-cross cyclists. However, there is no bridleway access to the peaks (except Ingleborough from the Ingleton side only) so any bicycle access is on a permissive basis on race days only.

 * The Three Peaks Race, has been held annually since 1954 and traditionally started at the Hill Inn until 1975, when the start moved to Horton. In 2008 this race was also the World Long Distance Mountain Running Challenge.
 * The Three Peaks Cyclo-Cross race follows a longer, 61 km, route across the peaks.
 * Yorkshire 3 Peaks Ultra, is a 70 km self navigation trails ultra marathon held annually in October. Starting in Hawes, joining the classic Yorkshire 3 Peaks route around Whernside, Ingleborough and Pen-y-ghent. Returning to Hawes via The Pennine Way.

Media
The Three Peaks were featured on the BBC Two programme Seven Natural Wonders as one of the wonders of Yorkshire.

title: Yorkshire Three Peaks


text:
The Reverend Horton Heat

The Reverend Horton Heat is the stage name of American musician James C. Heath (born 1959) as well as the name of his Dallas, Texas-based psychobilly trio. Heath is a singer, songwriter and guitarist. A Prick magazine reviewer called Heath the "godfather of modern rockabilly and psychobilly".

The group formed in 1986, playing its first gigs in Dallas' Deep Ellum neighborhood. The core members are Jim "Reverend Horton" Heath on guitars and lead vocals, and Jimbo Wallace on the upright bass. The band signed to Victory Records in 2012, and released its 12th studio album, Whole New Life, on November 30, 2018.

The band plays rock and roll with influences from 1950s country, surf, punk, big band, swing, and rockabilly standards.

Early career
Heath was born in Corpus Christi, Texas, where he was raised with an appreciation of rock, electric blues and rockabilly. He was influenced by country music artists such as Junior Brown, Willie Nelson, and Merle Travis. He played in local bands until 1985 when he gained notice in Dallas as "Reverend Horton Heat", the moniker bestowed by the owner of the Deep Ellum neighborhood nightclub where he played.

Adding bassist Jimbo Wallace and drummer Taz Bentley in 1989, Reverend Horton Heat recorded for Sub Pop at Reciprocal Recording in Seattle and Crystal Clear in Dallas, which made up the majority of material on Reverend Horton Heat's debut album, Smoke 'Em If You Got 'Em (1990). For their next album, the band recorded with Gibby Haynes of the Butthole Surfers producing at Ardent Studios in Memphis: The Full-Custom Gospel Sounds of the Reverend Horton Heat (1993).

Interscope Records joined with Sub Pop to co-release the band's third album Liquor in the Front (1994). Al Jourgensen of Ministry produced the album.

Chart success
Scott Churilla replaced Bentley as drummer in the mid-1990s, and the band released It's Martini Time in 1996. The album brought the band its first Billboard chart success, reaching number 165 on the Billboard 200. The band covered the boogie standard "Rock the Joint", and the song "It's Martini Time" was a minor hit. Later that year, Heath brought his street preacher style to the television series Homicide: Life on the Street, and he appeared on The Drew Carey Show in 1997.

The 2000 album Spend a Night in the Box was released through Time Bomb Recordings, with Paul Leary producing. The style was a return to straight-ahead rockabilly songs. The album rose through CMJ charts to peak at number 2 in May.

The song "Like a Rocket" served as the theme for the 2002 Daytona 500 autosports race. The band featured the song on their next album, Lucky 7.

Victory Records signed Reverend Horton Heat in 2012, and Scott Churilla returned to the band as drummer, playing for the next five years. An album titled Rev was released on January 21, 2014. A YouTube video for a single on the album, "Let Me Teach You How to Eat," preceded the album on November 12, 2013. Rev rose to number 111 on the Billboard 200, becoming the band's highest-charting album. The band toured as opening act for Motörhead, and recorded rock and roll songs with Motörhead's Lemmy Kilmister, though the tapes are unreleased. Reverend Horton Heat also backed a number of other artists such as Unknown Hinson, Jello Biafra and Deke Dickerson.

In 2017, drummer Churilla was replaced by Arjuna "R.J." Contreras, formerly of the band Eleven Hundred Springs. Matt Jordan of West Virginia joined the band playing piano and organ as well as supporting vocals. They released the album Whole New Life in 2018.

In 2021, Heath and Wallace teamed with drummer Slim Jim Phantom (Stray Cats) to form a side project: The Jimbos.

The Trio will release a live album on called Live In Houston on December 22, 2023.

Commercial appearances
"Psychobilly Freakout", and later "Wiggle Stick", were both featured in video segments on the show Beavis and Butt-Head. The song "I Can't Surf" was part of the soundtrack of the video game Tony Hawk's Pro Skater 3, published in 2001. “In Your Wildest Dreams” was used in the NBC drama Homicide: Life on the Street, episode “Full Moon” (season 4, episode 17, aired April 5, 1996), in which Reverend Horton Heat also appears. "Psychobilly Freakout" was used on a commercial for Buell American Motorcycles and a slightly altered version was featured in the game Guitar Hero II and later on Guitar Hero Smash Hits. Their song "Baddest of the Bad" is featured on the soundtrack to Tony Hawk's Proving Ground. The 1997 video game Redneck Rampage also includes two of their songs, "Wiggle Stick" and "Nurture My Pig!". The song "Big Red Rocket of Love" is featured in the video games The Sims 3, MotorStorm and Need for Speed: The Run, and a slightly altered version of the song was featured in a 1999 television commercial for the Mazda Miata. The song "Pride of San Jacinto" is featured on the video game Hot Wheels Turbo Racing. The song "Let Me Teach You How to Eat" was featured in a 2017 Subway commercial. The song "Mad, Mad Heart" is featured in the video game Far Cry 5.

Equipment
Heath has a signature guitar from the Gretsch Guitar company, the 6120RHH. One of his favorite vintage guitars is a 1954 Gibson ES-175, which he rarely plays on the road since its wiring buzzes in certain venues. His favorite amplifier was the Fender Super Reverb but is now the Gretsch Executive.

Current members

 * Jim Heath: guitars, vocals (1985–present)
 * Jimbo Wallace: upright bass (1989–present)
 * Jonathan Jeter: drums (2020–present)

Former members

 * "Swingin'" Jack Barton: upright bass (1985–1989)
 * Bobby Baranowski: drums (1985–1989)
 * Kyle Thomas: drums (1989)
 * Patrick "Taz" Bentley: drums (1989–1994)
 * Tim Alexander: piano/keyboards (1996– Jun. 2017)
 * Paul Simmons: drums (2006–2012)
 * Scott Churilla: drums (1995–2006, 2012–2017)
 * Matt Jordan: piano (Sep. 2017– Feb. 2019)
 * Arjuna “RJ” Contreras: drums (2017-2020)

Collections

 * Holy Roller: 24 Hits (Sub Pop, 1999)
 * 20th Century Masters – The Millennium Collection: The Best of The Reverend Horton Heat (Interscope, 2006)
 * 25 To Life [live] (Yep Roc, 2012)

Singles

 * "Big Little Baby" (1988)
 * "Psychobilly Freakout" (1990)
 * "400 Bucks / Caliénte" (split with The Supersuckers) (1994)
 * "One Time for Me" (1994) No. 40 Alternative songs
 * "Lie Detector" (1998)
 * "King" (1999)
 * "It Was a Very Good Year" (2000)
 * "Let Me Teach You How to Eat" (2013)
 * "It's a Rave Up!/Beer, Write This Song" (2015)
 * "Hardscrabble Woman/Lying to Myself" (2016)

DVDs

 * Live and In Color (2003)
 * Reverend Horton Heat: Revival (2004)

Soundtracks

 * Film
 * Love and a .45 – "The Devil's Chasing Me" (1994)
 * Ace Ventura: When Nature Calls – "Watusi Rodeo" (1995)
 * Bio-Dome – "Psychobilly Freakout" (1996)
 * Free Willy 3: The Rescue – "Big Sky" (1997)
 * Major League: Back to the Minors – "Baby I'm Drunk" (1998)
 * The Flintstones in Viva Rock Vegas – "Rock the Joint" (2000)
 * Auto Focus – "Real Gone Lover" (2002)

 * Television
 * Homicide: Life on the Street (episode #4.17 "Full Moon") – "In Your Wildest Dreams" (1996)
 * Cleveland Rocks! Music from The Drew Carey Show – "Now, Right Now" (1998)
 * Dexter: New Blood (episode #8 "Unfair Game") – "Baddest of the Bad" (2021)

 * Video games
 * Redneck Rampage – "Nurture My Pig" and "Wiggle Stick" (1997)
 * Space Bunnies Must Die! – "In Your Wildest Dreams" (1998)
 * Hot Wheels Turbo Racing – "Pride of San Jacinto" (1999)
 * Tony Hawk's Pro Skater 3 – "I Can't Surf" (2001)
 * Guitar Hero II – "Psychobilly Freakout" (2006)
 * MotorStorm – "Big Red Rocket of Love" (2007)
 * Tony Hawk's Proving Ground – "Baddest of the Bad" (2007)
 * The Sims 3 Fast Lane Stuff – "Big Red Rocket of Love" (2010)
 * Need for Speed: The Run – "Big Red Rocket of Love" (2011)
 * Steep – "Chasing Rainbows" (2016)

Film appearances

 * Love and a .45 (1994) "Loaded Gun" was performed by the Reverend Horton Heat in the film, but does not appear on the soundtrack album.

Collaborations

 * RevOrganDrum (Yep Roc, 2007)

title: The Reverend Horton Heat


text:
Fédération Internationale de Roller Sports

The Fédération Internationale de Roller Sports (FIRS; International Federation of Roller Sports) was the world governing body for roller sports, including skateboarding, rink hockey, inline hockey, inline speed skating, inline alpine, downhill, roller derby, roller freestyle, inline freestyle, aggressive inline skating, inline figure skating and artistic roller skating. It was established in April 1924 in Montreux, Switzerland by two Swiss sportsmen, Fred Renkewitz and Otto Myer, who had close connections to the International Olympic Committee.

The FIRS gathered more than 100 national federations, including countries from every continent and they are affiliated with the International Skating Union.

A proposal to dissolve the federation and merge with the International Skateboarding Federation to form a new body known as World Skate was ratified in September 2017. Since 2017 World Skate has organised the World Roller Games, comprising all the world roller sport disciplines as regulated by the World Skate international federation.

FIRS
The FIRS aimed to foster the Roller Sports movement and participation on a global scale. Its areas of responsibility were as follows:
 * 1) Administration and Regulations
 * 2) Organizing international competitions
 * 3) Developing the movement worldwide
 * 4) Promoting

The authority of FIRS was recognized by the following organizations:
 * International Olympic Committee (IOC)
 * General Association of International Sports Federations (GAISF)
 * International World Games Association (IWGA)
 * Pan American Sports Organization (PASO)

FIRS recognized the following continental confederations:
 * Africa – African Confederation of Sports of Roller Skating (ACSRS)
 * Europe – Confédération Européenne de Roller Skating (CERS)
 * Asia – Confederation of Asia Roller Sports (CARS)
 * Oceania – Oceania Confederation of Roller Sports (OCRS)
 * The Americas – Confederación Panamericana de Roller Sports (CPRS)

Each continental confederation comprises or recognizes, in turn, various national governing bodies and associations.

Skating is considered to be one of the most complete physical exercises that exist and enjoys huge popularity on a world level. According to the latest estimations, there are more than 40 million habitual users of recreational skates throughout the world.

FIRS Roller Hockey Competitions

 * Club Competitions
 * Rink hockey World Club Championship
 * Roller Hockey Intercontinental Cup
 * National Teams Competitions

 * FIRS Roller Hockey World Cup
 * FIRS Women's Roller Hockey World Cup
 * FIRS Roller Hockey World Cup U-20

Disciplines and World Championships

 * Men's Roller Derby World Cup and Women's Roller Derby World Cup organized by Blood & Thunder magazine, not FIRS.


text:
White Sea–Baltic Canal

The White Sea–Baltic Canal (Беломо́рско-Балти́йский кана́л), often abbreviated to White Sea Canal (Belomorkanal) is a ship canal in Russia opened on 2 August 1933. It connects the White Sea, in the Arctic Ocean, with Lake Onega, which is further connected to the Baltic Sea. Until 1961, it was called by its original name: the Stalin White Sea–Baltic Canal (Belomorsko-Baltiyskiy Kanal imeni Stalina).

The canal was constructed by forced labor of gulag inmates. Beginning and ending with a labor force of 126,000, between 12,000 and 25,000 laborers died according to official records, while Anne Applebaum's estimate is 25,000 deaths.

The canal runs 227 km, partially along several canalized rivers and Lake Vygozero. As of 2008, it carries only light traffic of between ten and forty boats per day. Its economic advantages are limited by its minimal depth of 3.5 m, inadequate for most seagoing vessels. This depth typically corresponds to river craft with deadweight cargo up to 600 tonnes, while useful seagoing vessels of 2,000–3,000 dwt typically have drafts of 4.5 - 6 m. The canal was originally proposed to be 5.4 m deep; however, the cost and time constraints of Stalin's first five-year plan forced the much shallower draught.

Waterway
The total length of the waterway is 227 km, of which 48 km are man-made. The current flows north from Lake Onega to the White Sea, and all navigation marks are set according to it. Once in Lake Onega, ships can exit the southwest shore through the Svir River (and its two locks) to reach Lake Ladoga and then proceed down the Neva River to Saint Petersburg and the Baltic Sea. Alternatively, from Lake Onega river ships can sail eastward into the Volga–Baltic Waterway.

Route
The canal begins near Povenets settlement in Povenets bay of Lake Onega. After Povenets there are seven locks close together, forming the "Stairs of Povenets". These locks are the southern slope of the canal. The canal summit pond at 103 m elevation is 22 km long between locks 7 & 8. The northern slope has twelve locks numbered 8–19. The route of the northern slope runs through five large lakes; Lake Matkozero between locks 8 & 9, Lake Vygozero between locks 9 & 10, Lake Palagorka between locks 10 & 11, Lake Voitskoye between locks 11 & 12 and Lake Matkozhnya between locks 13 & 14. The canal empties out into the Soroka Bay of the White Sea at Belomorsk. The settlements of Povenets, Segezha, Nadvoitsy, Sosnovets, and Belomorsk are located along the canal.

Sailing conditions
Minimum lock dimensions are 14.3 m wide by 135 m long. The navigable channel is 36 m wide and 3.5 m deep, with a radius of curvature of 500 m. Speed is limited to 8 km/h in all artificial portions. In conditions of low visibility (less than one km) navigation is halted.

For the navigation seasons of 2008 to 2010, the canal locks were scheduled to operate from 20 May to 15–30 October, giving 148–163 navigation days per year.

Profile
The following illustration depicts the profile of the White Sea–Baltic Canal. The horizontal axis is the length of the canal. The vertical axis is the elevation of the canal segments above mean sea level.

Construction
The Soviet Union presented the canal as an example of the success of the first five-year plan. Its construction was completed four months ahead of schedule, though it was too shallow for the planned use. The canal was constructed in twenty months, between 1931 and 1933, almost entirely by manual labor.

The canal was the first major project constructed in the Soviet Union using forced labor. BBLAG, the Directorate of the BBK Camps, managed the construction, supplying a workforce of an estimated 100,000 convicts, at the cost of huge casualties. Although prison labor camps were usually kept secret, the White Sea Canal was a propaganda showcase of convicts "reforging" themselves in useful labor (Soviet concept of perekovka, reforging or rehabilitation).

Marshall Berman states that "The canal was a triumph of publicity; but if half the care that went into the public relations campaign had been devoted to the work itself, there would have been far fewer victims and far more development."

Organization and management
The workforce for the Canal was supplied by the Belbaltlag camp directorate (White Sea–Baltic Corrective Labor Camp Directorate, WSBC) of the OGPU GULAG.
 * P. F. Aleksandrov (П. Ф. Александров), acting chief of WSBC, January 16, 1932, full chief from March 28, 1932, to at least January 15, 1933
 * Matvei Berman, head of the Gulag during most of the 1930s, direct supervisor of Firin
 * Semyon Firin, Chief of Construction, also mentioned in 1933 documents as chief of WSBC
 * Naftaly Frenkel, Chief of Works, November 16, 1931, to the end of construction.
 * Lazar Kogan, chief of the BBK Construction Directorate
 * Yakov Rapoport, deputy chief of the BBK Construction Directorate
 * Edward Senkevich, chief of WSBC, November 16, 1931 – January 16, 1932, also assistant chief of the BBK Construction Directorate

Genrikh Yagoda, Deputy Chairman of the OGPU, as well as Berman, Firin, Kogan, and Rappoport were awarded the Order of Lenin for the completion of the canal by the Politburo on July 15, 1933.

Working conditions
The Soviets portrayed the project as evidence of the efficiency of the Gulag. Supposedly "reforging class enemies" (political prisoners) through "corrective labor", the working conditions at the BBK Camp were brutal, with the prisoners given only primitive hand tools to carry out the massive construction project. The mortality rate was about 8.7%, with many more sick and disabled.

The workforce was organized into brigades of 25–30, which made up phalanges of 250–300. There were norms for labor, for example 2.5 m3 of hand-dug stone per day per brigade. There was an extensive system of incentives for prisoners in place. The food rations for prisoners who exceeded quotas were increased. Those who fulfilled and exceeded the norm (2.5 m³ per day for earthworks) received an increased bread ration (up to 1200 g), a bonus dish (for example, 75-gram pies with cabbage or potatoes), and a cash bonus. Moral incentives were also used: presenting the brigade or phalange with a Red Banner, declaring gratitude, presenting certificates, placing the names of shock workers on the honor board, as well as counting 3 working days for 5 days of work, and for shock workers - “a day in two”. At other times these teams were pitted to compete against each other in surpassing the norms, and promises were made of shortened sentences, food and cash bonuses for the champions. After the successful construction, 12,484 prisoners were freed as reward, and 59,516 prison terms were shortened. 12,300 workers died during the building process, according to the official records, including in 1931 - 1438 (2.24% of the number of workers), in 1932 - 2010 (2.03%), in 1933 - 8870 (10.56%), which was due to a reduction in supplies due to famine in the country and the rush before the completion of construction while Anne Applebaum's estimate is 25,000 deaths.

The canal and Russian writers
A carefully prepared visit in August 1933 to the White Sea–Baltic Canal may have hidden the worst of the brutality from a group of 120 Russian writers and artists, the so-called Writers Brigade, including Maxim Gorky, Aleksey Nikolayevich Tolstoy, Viktor Shklovsky, and Mikhail Zoshchenko, who compiled a work in praise of the project, the 600-page The I.V. Stalin White Sea – Baltic Sea Canal (Беломорско-Балтийский канал имени Сталина), published at the end of 1934. Shklovsky visited the White Sea Canal on his own rather than with the group. Gorky, who had previously visited the Solovetski Islands labor camp in 1929 and written about it in the Soviet journal Our Accomplishments, organized the White Sea trip, but did not himself join it. Also along on the White Sea trip was Nikolai Pogodin, screenwriter of Convicts, a 1936 comedy about the BeltBaltLag labor camp.

It is likely that at least some of the visiting writers were aware of the brutality of camp life. In fact, one of the contributors, Sergei Alymov, was a prisoner at the camp and editor of the camp newspaper Perekovka ("Reforging"). Similarly, Aleksandr Avdeenko's account of Belomor includes conversations between OGPU chief Semyon Firin and Prince Mirsky that reveal at least some of the writers were aware of its true nature.

In 1930s
After the canal had been completed and opened for navigation, the Belbaltlag (White Sea-Baltic Camp) was reorganized into the White Sea-Baltic Combine (Baltiysko-Belomorsky Kombinat [BBK]), still within the NKVD system, by an order of the Council of People's Commissars of August 17, 1933. The Combine was charged with operating the canal and managing the economic development of the adjacent areas, including 2.8 million hectares of forest lands and the industrial facilities that had been constructed along the route.

A major part of the Combine's workforce consisted of 75–85,000 Belbaltlag prisoners. In addition, the Combine included 21 "special settlements" (spetsposyolok) with some 30,000 residents, mostly dispossessed farm families transported to Karelia from the USSR's warmer regions. In addition to convicts and "special settlers", the Combine employed about 4,500 free employees and a paramilitary security force. In all, the Combine's employees accounted for about 25% of the population of the Karelian Autonomous Soviet Socialist Republic.

Until 1936, all financial transactions of the Combine were exempt from taxes and duties.

The BBK led to the development of Belomorsk as a major industrial city. New cities and urban-type settlements developed along the route of the canal, such as Medvezhyegorsk, Segezha, Nadvoitsy. Povenets, which had been demoted from a town to a village in the 1920s, now became a town again, and a large port.

As is discussed further below, during the 1930s a number of smaller naval vessels were transferred from the Baltic to the White Sea to provide warships for the Soviet Northern Naval Flotilla, which became the Northern Fleet in 1937.

In World War II
There was no action near the White Sea–Baltic Canal during the Winter War of 1939–1940, when the USSR invaded Finland. With Germany's full-scale invasion of the USSR in 1941, supported by Finland in the Continuation War, the canal route became the front line.

On June 23, 1941, the day after the German invasion, 16 Finnish commandos were ferried to the canal by two German Heinkel He 115 seaplanes from Oulujärvi. The commandos were Finnish volunteers recruited by the German Major Schaller, and were equipped with German uniforms and weapons, as the Finnish General Staff wanted no responsibility for the operation. The commandos were to blow up the canal locks, but they failed due to heightened security.

On June 28, the canal was bombed for the first time by the Finnish Air Force, targeting Locks No. 6, 7, 8, and 9, followed the next day by Finnish troops advancing along the Finland-USSR border. The air bombings of the Povenets lock ladder succeeded in interrupting boat traffic on the canal only from June 28 to August 6, and then again from 13 to 24 August 1941. On August 28, the fifth and final bombing raid of the 1941 navigation season took place against Lock No. 7, but it did no damage.

In August, the management of the BBK and most of the 800 canal staff were evacuated from Medvezhyegorsk to Lock No. 19 in Belomorsk, with only 80 left at their stations.

In November, a caravan of passenger vessels evacuating families of Povenets canal workers and residents, along with equipment, froze into the ice of Lake Vygozero. On the night of November 12/13, another boat caravan froze in Zaonezhsky Bay near Megostrov Island, and was later captured by Finnish troops. On December 5, Finnish troops entered Medvezhyegorsk.

On December 6 in a -37 °C frost, Finnish troops captured Povenets, the southern entrance to the BBK. On the same day, Soviet troops started demolishing canal structures. Lock No. 1 was the first to be blown up. By the morning of December 8, Locks No 1 to 6, and dams No. 4 and 20 had all been demolished.

At the same time, heavy fighting took place near the Povenets Lock Ladder (Locks No. 1 to 7). The Finns crossed the canal and captured Gabselga village to the east, but after a few days of fighting they were pushed back to the canal's western side.

Soviet sappers blew up Lock No. 7 on December 11 after the Red Army had retreated. Once the locks of the Povenets Ladder had been destroyed, water from the watershed lakes poured freely into Lake Onega through Povenets village, which was nearly completely destroyed by the flood. The route of the BBK had become the front line, separating the Finnish troops on the canal's western bank from the Soviet forces on its eastern bank. The opposing armies held these positions until June 1944.

Postwar years
After Finland left the war in September 1944, the damage to the canal, including the complete destruction of its southern section and the town of Povenets and damage to lighthouses and other structures, was repaired. Rebuilding was completed by July 1946, with navigation through the canal restored on July 28, 1946.

On February 2, 1950, the RSFSR Council of Ministers issued an order for the overhaul and reconstruction of the BBK's structures, with gradual electrification of the canal's structures and machinery. In 1953, the locks' staff hired electricians; by 1957, the electrification of the locks of the northern slope was completed; and by 1959 all coastal and floating navigation lights were switched to electric power.

The importance of BBK for the national economy greatly increased after the commissioning of the modern Volga–Baltic Waterway in 1964. Canal capacity and the annual volume of freight traffic increased several-fold.

Another upgrade took place in the 1970s. During the reconstruction, the guaranteed depth of the fairway was increased to 4 meters, and the channel became part of the Unified Deep Water System of European Russia.

Canal use
During the first navigation in 1933, 1.143 million tons of cargo and 27.000 passengers were transported through the canal. In 1940 traffic volume was approximately 1 million tons, representing 44% of capacity

Cargo tonnage peaked in 1985, with 7.3 million tonnes transported. Tonnage remained high until 1990, then declined after the fall of the Soviet Union. Usage rose gradually in the 21st century, but remained well below the Soviet-era peak, with just 0.3 million tonnes in 2002.

During the 2007 season, the canal carried 0.4 million tonnes of cargo along with 2,500 passengers. It is now operated by the White Sea and Lake Onega Waterways and Shipping Administration (Беломорско-Онежское государственное бассейновое управление водных путей и судоходства), which is also responsible for shipping on Lake Onega and in the Belomorsk harbor area (but not in the open waters of the White Sea). The canal was seemingly a small part of the agency's overall shipping business, which in 2007 amounted to 4.6 million tonnes and 155,000 passengers.

According to official statistics, a total of 193 million tonnes of cargo was transported over the canal over its first 75 years (1933–2008).

The canal makes it possible to ship heavy and bulky items from Russia's industrial centers to the White Sea, and then by sea-going vessels to Siberia's northern ports. For example, in the summer of 2007, a large piece of equipment for Rosneft's Siberian Vankor Oil Field was delivered by the Amur-1516 from Dzerzhinsk on the Oka River, via the Volga–Baltic Waterway and the White Sea Canal to Arkhangelsk, and from there by the ocean-going SA-15 class Arctic cargo ship Kapitan Danilkin to Dudinka on the Yenisei River. In 2011, heavy equipment for the Sayano-Shushenskaya hydro power plant was shipped from Saint Petersburg via the canal, the Arctic Sea, and the Yenisei River.

Oil product shipping
In Soviet times, the canal was used for shipping oil products from refineries on the Volga River to consumers in the Murmansk Oblast and overseas. Russia's Volgotanker Company, with a fleet of suitably sized petroleum tankers and ore-bulk-oil carriers, pioneered this route starting August 1970, when Nefterudovoz-3 delivered a cargo of fuel oil to the White Sea port of Kandalaksha.

After many years of interruption, Volgotanker resumed the canal route in 2003. The company had plans to carry 800,000 tonnes of fuel oil over the canal during 2003, and to increase the volume to 1,500,000 t in 2004. The fuel was transferred from Volgotanker river tankers to Latvian seagoing tankers at a floating transfer station near the Osinki Island in the Onega Bay on the White Sea, 36 km northwest of the port of Onega.

Transfer operations began 24 June 2003, but on 1 September a low-speed collision between Volgotanker's Nefterudovoz-57M and the Latvian Zoja-I during a transfer caused a crack in the Nefterudovoz's hull, with a subsequent oil spillage estimated at 45 t, of which only 9 t were recovered. Volgotanker's alleged failure to contain the spill resulted in the Arkhangelsk Oblast authorities shutting down the oil transfer operation with only 220,000 tonnes exported. The company was fined and future operations were refused.

Military use
Soviet (and later Russian) naval strategists long believed that a well-designed canal system could help establish contact among the separate fleets based on Russia's Black Sea, Baltic, Arctic, Pacific, and Caspian coasts. The White Sea Canal was also constructed with this military use in mind, and early in its history the Northern Fleet's first warships sailed along the canal to the White Sea from the Baltic, Before World War II, the canal was used for the transfer of military vessels between the two seas on 17 occasions.

During World War II, in August–September 1941, the canal was used to move a number of submarines from the Baltic Fleet to the White Sea, including submarines K-3, S-101 and S-102, L-22. Some unfinished submarines from Leningrad's Baltic Shipyard and Gorky's Krasnoye Sormovo shipyard sailed to the new Sevmash shipyard in Severodvinsk.

Since then, the canal has been regularly used for delivering submarines by transporter dock from the Baltic Shipyard and Krasnoye Sormovo to Sevmash for completion.

Hydroelectric stations
The canal system includes five hydroelectric power plants with total production capacity of 240 MW.

Commemoration
The canal gave its name to the Belomorkanal Soviet cigarette brand.

There is a monument at Povenets for the prisoners who perished during the construction, and a smaller memorial in Belomorsk near the White Sea end. There was even a comedic play written about the canal by Nikolay Pogodin.

The canal project also gave the Russian language the slang word "zeka", "zek, z/k" for "inmate". In Russian, "inmate", "incarcerated" is заключённый (zakliuchyonnyi), usually abbreviated to "з/к" in paperwork, and pronounced as "зэка" (, "zeh-KA"), which gradually transformed into "зэк" and "зек", zek (both pronounced as ). The word is still in colloquial use. Originally the abbreviation stood for zaklyuchyonny kanaloarmeyets (заключённый каналоармеец), literally "incarcerated canal-army-man". The latter term coined in an analogy with the words "krasnoarmeyets" meaning "member of the Red Army" or trudarmeyets (member of a labor army). According to the Soviet account, in 1932 when Anastas Mikoyan visited the Belomorstroy construction site, Lazar Kogan asked, "Comrade Mikoyan, what shall we call them? (…) I thought up the word: 'kanaloarmeyets'. What do you think?" Mikoyan approved.

title: White Sea–Baltic Canal


text:
Skinnerbox

Skinnerbox is a third wave ska band formed in New York City in the late 1980s by King Django.

Full Length

 * Instrumental Conditioning (Stubborn) 1990)
 * Now & Then (Stubborn) (1992)
 * Tales of the Red (Stubborn) (1993)
 * What You Can Do, What You Can't (Moon Ska) (1997)
 * Demonstration (Triple Crown Records/Stubborn)(1998)

EPs

 * Sunken Treasure (Stubborn) (1994)

7" Singles

 * "Does He Love You" b/w "Right Side" (Stubborn) (1993)
 * Hepcat Season b/w I Got To Know (Stubborn) (1998)

Compilations

 * Special Wild 1989-1994 (Stubborn) (1996)

title: Skinnerbox