| Orycterocetus Temporal range: Miocene | |
|---|---|
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Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | Physeteridae |
| Genus: | † Orycterocetus Leidy, 1853 |
| Species | |
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Orycteocetus is an extinct genus of sperm whale from the Miocene of the northern Atlantic Ocean.
Orycterocetus is a member of Physeteroidea closely related to crown-group sperm whales. The type species, O. quadratidens, was first named by Joseph Leidy on the basis of two teeth, two partial mandibular rami, and a rib from Neogene deposits of Virginia. [1] Two more species were subsequently described, O. cornutidens Leidy 1856 [2] and O. crocodilinus Cope, 1868, [3] the latter from the middle Miocene Calvert Formation.
Joseph Mellick Leidy was an American paleontologist, parasitologist and anatomist.
Basilosauridae is a family of extinct cetaceans. They lived during the middle to the early late Eocene and are known from all continents, including Antarctica. They were probably the first fully aquatic cetaceans. The group is noted to be a paraphyletic assemblage of stem group whales from which the monophyletic Neoceti are derived.
Aublysodon is a genus of carnivorous dinosaurs known only from the Judith River Formation in Montana, which has been dated to the late Campanian age of the late Cretaceous period. The only currently recognized species, Aublysodon mirandus, was named by paleontologist Joseph Leidy in 1868. It is now considered dubious, because the type specimen consists only of an isolated premaxillary (front) tooth. Although this specimen is now lost, similar teeth have been found in many US states, western Canada, and Asia. These teeth almost certainly belong to juvenile tyrannosaurine tyrannosaurids, but most have not been identified to species level. However, it is likely that the type tooth belongs to one of the species in the genus Daspletosaurus, which was present in contemporary formations, and which matches specific details of the original tooth. The synapomorphies alleged to distinguish the Aublysodontinae, especially lack of serrations on premaxillary teeth could have been caused by tooth wear in life, postmortem abrasion, or digestion. Most other "aublysodontine"-type teeth may be from ontogenetic stages or sexual morphs of other tyrannosaurids.
Belodon is a genus of phytosaur, a crocodile-like reptile that lived during the Triassic. Its fossils have been found in Europe and elsewhere. The type species, Belodon plieningeri, was named by prolific German paleontologist Christian Erich Hermann von Meyer in 1844.
Thespesius is a dubious genus of hadrosaurid dinosaur from the late Maastrichtian-age Upper Cretaceous Lance Formation of South Dakota.
Kentriodon is an extinct genus of toothed whale related to modern-day dolphins. Fossils have been found in North America, Europe and Japan. Several species have been described.
Zygophyseter varolai is an extinct sperm whale that lived during the Tortonian age of the Late Miocene 11.2 to 7.6 million years ago. It is known from a single specimen from the Pietra Leccese Formation in Italy. It was a member of a stem group of fossil macroraptorial sperm whales also including Brygmophyseter, Acrophyseter, and Livyatan. It probably grew to be around 6.5 to 7 meters in length and shared some characteristics with other raptorials, such as large teeth with tooth enamel that were functional in both the upper and lower jaws which the modern sperm whale lacks. It also had a beak, the ability to echolocate prey, and could have probably swum faster than the modern-day sperm whale which can reach 4 kilometers per hour (2.5 mph). These were probably used in the capture of large prey, such as large fish, seals, and whales. In fact, its common name, the killer sperm whale, refers to its feeding habits that would have had a resemblance to the modern-day killer whale.
Ontocetus is an extinct genus of walrus, an aquatic carnivoran of the family Odobenidae, endemic to coastal regions of the southern North Sea and the southeastern coastal regions of the U.S. during the Miocene-Pleistocene. It lived from 13.6 mya—300,000 years ago, existing for approximately 13.3 million years.
Brygmophyseter, known as the biting sperm whale, is an extinct genus of toothed whale in the sperm whale family with one species, B. shigensis. When it was first described in 1994, the species was placed in the genus Scaldicetus based on tooth morphology, but this was later revised in 1995. In 2006, it was classified into the genus Naganocetus, which is considered to be a junior synonym. The only known specimen, a nearly complete skeleton, was dated to be around 14–15 million years old. Brygmophyseter is thought to have been 6.5–7 meters (21–23 ft) long, and it probably had 11 or 12 teeth in the upper and lower jaws. Brygmophyseter is part of a group of macroraptorial sperm whales which tended to be apex predators using their large teeth to catch struggling prey such as whales. It had a spermaceti organ which was probably used for biosonar like in the modern sperm whale. The whale has made an appearance on The History Channel's TV series Jurassic Fight Club.
Acrophyseter is a genus of extinct sperm whales that lived in the Late Miocene off the coast of Peru comprising two species: A. deinodon and A. robustus. It is part of a group of macroraptorial sperm whales which all shared several features for the purpose of hunting large prey, such as deeply-rooted and thick teeth. Acrophyseter measured 4–4.5 metres (13–15 ft), making it the smallest raptorial sperm whale. Because of its short pointed snout, and its strong curved front teeth, it probably fed on the large marine vertebrates of its time, such as seals and other whales.
Thecachampsa is an extinct genus of gavialoid crocodylian, traditionally regarded as a member of the subfamily Tomistominae. Fossils have been found from the eastern United States in deposits of Miocene age. Those named in the 19th century were distinguished primarily by the shape of their teeth, and have since been combined with T. antiquus. More recently erected species were reassigned from other genera, although their assignment to Thecachampsa has since been questioned.
Cetotheriidae is a family of baleen whales. The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by Fordyce & Marx 2013 recovered the living pygmy right whale as a member of Cetotheriidae, making the pygmy right whale the only living cetotheriid, other authors either dispute this placement or recover Neobalaenidae as a sister group to Cetotheriidae.
Scaldicetus is an extinct genus of highly predatory macroraptorial sperm whale. Although widely used for a number of extinct physeterids with primitive dental morphology consisting of enameled teeth, Scaldicetus as generally recognized appears to be a wastebasket taxon filled with more-or-less unrelated primitive sperm whales.
Peripolocetus is a genus of balaenid baleen whale from the middle Miocene of Kern County, California.
Pontobasileus is an archaeocete whale known from a fragment of a single tooth described by Leidy 1873. It can questionably be dated to the Eocene of Alabama.
Lophocetus is an extinct genus of dolphin belonging to the clade Delphinida that is known from late Miocene (Tortonian) marine deposits in California and Maryland. Although usually placed in Kentriodontidae, recent studies have found it only distantly related to Kentriodon.
Agorophius is an extinct genus of toothed whale that lived during the Oligocene period, approximately 32 million years ago, in the waters off what is now South Carolina.
Hoplocetus is an extinct genus of raptorial cetacean of the sperm whale superfamily, Physeteroidea. Its remains have been found in the Miocene of Belgium, France, Germany and Malta, the Pliocene of Belgium and France, and the Pleistocene of the United Kingdom and South Carolina.
Ischyrotherium is an extinct genus named by Joseph Leidy in 1856 for fossils from the lignite deposits in Nebraska. Originally considered an herbivorous cetacean, Leidy then reassigned it to Sirenia as a relative of manatees, before Edward Drinker Cope reclassified it as a non-mammalian, suggesting the new name Ischyrosaurus to better identify its reptilian origins, as he considered it a sauropterygian. Ischyrotherium was found alongside material from the hadrosaur Thespesius and turtles Compsemys and Emys, and the fish Mylognathus. The name Ischyrosaurus was also used by John Whitaker Hulke for the sauropod now known as Ornithopsis manseli, as he was unaware it was preoccupied by Cope.
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