Piacenzian extinctions

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 Early Pliocene epochs. This prehistoric fish was once 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.

Thylacosmilus is an extinct genus of saber-toothed metatherian mammals that inhabited South America from the Late Miocene to Pliocene epochs. Though Thylacosmilus looks similar to the "saber-toothed cats", it was not a felid, like the well-known American Smilodon, but a sparassodont, a group closely related to marsupials, and only superficially resembled other saber-toothed mammals due to convergent evolution, with the aforementioned Thylacosmilus being one of the last known sparassodonts. A 2005 study found that the bite forces of Thylacosmilus and Smilodon were low, which indicates that the

Chalicotheriidae (from Ancient Greek χάλιξ (khálix), meaning "gravel", and θηρίον (theríon), meaning "beast") is an extinct family of herbivorous, perissodactyl mammals. Unlike living odd-toed ungulates, chalicotheriids bore large claws rather than hooves, although their dentition was adapted for browsing. The family is known from the Oligocene to the Pleistocene, reached its greatest diversity in the Miocene, and is known from Asia, Europe, Africa and North America. Asia appears to have been the main centre of diversification for the group.

Anthracotheriidae is a paraphyletic family of extinct, hippopotamus-like artiodactyl ungulates related to hippopotamuses and whales. The oldest genus, Elomeryx, first appeared during the middle Eocene in Asia. They thrived in Africa and Eurasia, with a few species ultimately entering North America during the Oligocene. They died out in Europe and Africa during the Miocene, possibly due to a combination of climatic changes and competition with other artiodactyls, including pigs and hippopotamuses. The youngest genus, Merycopotamus, died out in Asia during the late Pliocene, possibly for the sam

Thalassocnus is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—T. antiquus, T. natans, T. littoralis, T. carolomartini, and T. yuacensis—represent a chronospecies, a population gradually adapting to marine life in one direct lineage. They are the only known aquatic sloths, but they may have also been adapted to a terrestrial lifestyle. They have been found in the Pisco Formation of Peru, the Tafna Formation of Argentina, and the Bahía Inglesa, Coquimbo, and Ho

The Albanerpetontidae (also spelled Albanerpetidae and Albanerpetonidae) are an extinct family of small amphibians, native to the Northern Hemisphere during the Mesozoic and Cenozoic. The only members of the order Allocaudata, they are thought to be allied with living amphibians belonging to Lissamphibia. Despite a superficially salamander-like bodyform, their anatomy is strongly divergent from modern amphibians in numerous aspects. The fossil record of albanerpetontids spans over 160 million years from the Middle Jurassic to the beginning of the Pleistocene, about 2.13–2 million years ago.

Chapalmalania is an extinct genus of procyonid from the Late Miocene or Early Pliocene to Early Pleistocene (Montehermosan to Uquian) of Argentina (Andalhualá Formation), Venezuela (San Gregorio Formation, Venezuela), and Colombia (Ware Formation, Cocinetas Basin, La Guajira).

Percrocutidae is an extinct family of hyena-like feliform carnivorans endemic to Asia, Africa, and Southern Europe from the Middle Miocene through the Pliocene, existing for about .

Dinohippus (from Ancient Greek δεινός (deinós), meaning "terrible", and ἵππος (híppos), meaning "horse") is an extinct equid which was endemic to North America from the late Hemphillian stage of the Miocene through the Zanclean stage of the Pliocene (10.3—3.6 mya) and in existence for approximately . Fossils are widespread throughout North America, being found at more than 30 sites from Florida to Alberta and from Mexico all the way down to Panama (Alajuela Formation). The majority of fossils of Dinohippus have been unearthed in the Western United States in Nevada, New Mexico, Utah, and Califo

thumb | right | Archaeopotamus Archaeopotamus is an extinct genus of Hippopotamidae that lived between 7.5 and 2.58 million years ago in Africa and the Middle East. The genus was described in 2005 to encompass species of hippos that were previously grouped in Hexaprotodon.

Merycopotamus is an extinct genus of Asian anthracothere that appeared during the Middle Miocene, and died out in the Late Pliocene. At the height of the genus' influence, species ranged throughout South Asia and South East Asia (Indonesia, Myanmar, and Thailand). With the extinction of the last species, M. dissimilis, the lineage of anthracotheres came to an end. Merycopotamus was closely related to the anthracothere genus Libycosaurus, which, unlike the former, never left Africa. In fact, some African fossils originally placed in Merycopotamus, but are now referred to Libycosaurus.

Polydolopimorphia is an extinct order of metatherians, closely related to extant marsupials. Known from the Paleocene-Pliocene of South America and the Eocene of Antarctica, they were a diverse group during the Paleogene, filling many niches, before declining and becoming extinct at the end of the Neogene. It is divided into two suborders, Bonapartheriiformes, and Polydolopiformes Most members are only known from jaw fragments, which have their characteristically generally bunodont teeth. The morphology of their teeth has led to proposals that polydolopimorphians may be crown group marsupials,

Blastomeryx is an extinct genus of musk deer endemic to North America. It lived during the Miocene epoch 20.4—10.3 mya, existing for approximately . There may be only one species, Blastomeryx gemmifer. == Description == Blastomeryx was long and looked like a modern chevrotain. Its canines were elongated into tusks which it probably used to uproot plants and fend off predators. While Blastomeryx (as well as modern musk deer) lacked antlers, a Middle Miocene species had bony knobs on its skull, which have been interpreted as incipient horns. Blastomeryx had a reduced radius and ulna, as well as

Idiocetus ("unique whale") is a genus of extinct cetaceans of the family Balaenidae.