Palaeonictis Late | |
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skull of Palaeonictis occidentalis | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Clade: | Pan-Carnivora |
Order: | † Oxyaenodonta |
Family: | † Oxyaenidae |
Subfamily: | † Palaeonictinae |
Genus: | † Palaeonictis de Blainville, 1842 |
Type species | |
†Palaeonictis gigantea de Blainville, 1842 | |
Species | |
Synonyms [5] | |
synonyms of genus:
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Palaeonictis ("ancient weasel") is an extinct genus of placental mammals from extinct subfamily Palaeonictinae within extinct family Oxyaenidae, that lived in Europe and North America from the late Paleocene to the early Eocene. [9]
In life, it would have resembled a large modern wolverine. This predatory mammal had heavy jaws and blunt robust teeth more suited for crushing bones, than slicing meat. This meant that the plantigrade Palaeonictis was at least a part-time scavenger. The biggest species, Palaeonictis peloria (meaning "terrible ancient weasel") is known from an incomplete jaw that must have measured over 20 centimetres (7.9 in) in length. This animal was the largest carnivore in its ecosystem. 55 million years ago, P. occidentalis (the size of a bear) evolved into the smaller P. wingi (the size of a coyote) within 200,000 years in the early Eocene due to global warming (paleoclimatology). By the end of the early Eocene ( 50 million years ago), Palaeonictis disappeared from North America, and by the early Eocene ( 55 million years ago) the last species of P. gigantea had vanished from Europe. [4] In fact, the entire family Oxyaenidae had become extinct worldwide (although its sister group Hyaenodonta continued to thrive for a while). This is traditionally assumed to be due to increased competition from miacids and nimravids belonging to the more successful order Carnivora, which eventually replaced earlier carnivorous mammal clades in the later Neogene as the world's top predators, though no evidence of direct competition is known, and carnivorans may have simply filled vacated niches.
Sarkastodon is an extinct genus of placental mammals from extinct subfamily Oxyaeninae within extinct family Oxyaenidae, that lived in Asia during the middle Eocene. It was a genus of large, carnivorous animals known only from a skull and jawbones. Sarkastodon was probably a hypercarnivore that preyed on large mammals in its range during the Middle Eocene, such as brontotheres, chalicotheres, and rhinoceroses. Its weight is estimated at 800 kg (1,800 lb), and its length at 3 m (10 ft).
Creodonta is a former order of extinct carnivorous placental mammals that lived from the early Paleocene to the late Miocene epochs in North America, Europe, Asia and Africa. Originally thought to be a single group of animals ancestral to the modern Carnivora, this order is now usually considered a polyphyletic assemblage of two different groups, the Oxyaenids and the Hyenodonts, not a natural group. Oxyaenids are first known from the Palaeocene of North America, while hyaenodonts hail from the Palaeocene of Africa.
Oxyaenidae is a family of extinct carnivorous placental mammals. Traditionally classified in order Creodonta, this group is now classified in its own order Oxyaenodonta within clade Pan-Carnivora in mirorder Ferae. The group contains four subfamilies comprising fourteen genera. Oxyaenids were the first to appear during the late Paleocene in North America, while smaller radiations of oxyaenids in Europe and Asia occurred during the Eocene.
Hyaenodon ("hyena-tooth") is an extinct genus of carnivorous placental mammals from extinct tribe Hyaenodontini within extinct subfamily Hyaenodontinae, that lived in Eurasia and North America from the middle Eocene, throughout the Oligocene, to the early Miocene.
Carnassials are paired upper and lower teeth modified in such a way as to allow enlarged and often self-sharpening edges to pass by each other in a shearing manner. This adaptation is found in carnivorans, where the carnassials are the modified fourth upper premolar and the first lower molar, however this may vary in family. These teeth are also referred to as sectorial teeth.
Miacidae is a former paraphyletic family of extinct primitive placental mammals that lived in North America, Europe and Asia during the Paleocene and Eocene epochs, about 65–33.9 million years ago. These mammals were basal to order Carnivora, the crown-group within the Carnivoraformes.
Miacis is an extinct genus of placental mammals from clade Carnivoraformes, that lived in North America from the early to middle Eocene.
Oxyaena is an extinct genus of placental mammals from extinct subfamily Oxyaeninae within extinct family Oxyaenidae, that lived in Europe, Asia and North America during the early Eocene.
Mesonychidae is an extinct family of small to large-sized omnivorous-carnivorous mammals. They were endemic to North America and Eurasia during the Early Paleocene to the Early Oligocene, and were the earliest group of large carnivorous mammals in Asia. Once considered a sister-taxon to artiodactyls, recent evidence now suggests no close connection to any living mammal. Mesonychid taxonomy has long been disputed and they have captured popular imagination as "wolves on hooves," animals that combine features of both ungulates and carnivores. Skulls and teeth have similar features to early whales, and the family was long thought to be the ancestors of cetaceans. Recent fossil discoveries have overturned this idea; the consensus is that whales are highly derived artiodactyls. Some researchers now consider the family a sister group either to whales or to artiodactyls, close relatives rather than direct ancestors. Other studies define Mesonychia as basal to all ungulates, occupying a position between Perissodactyla and Ferae. In this case, the resemblances to early whales would be due to convergent evolution among ungulate-like herbivores that developed adaptations related to hunting or eating meat.
Dissacus is a genus of extinct carnivorous jackal to coyote-sized mammals within the family Mesonychidae, an early group of hoofed mammals that evolved into hunters and omnivores. Their fossils are found in Paleocene to Early Eocene aged strata in France, Asia and southwest North America, from 66 to 50.3 mya, existing for approximately 15.7 million years.
Didymictis is an extinct genus of placental mammals from extinct subfamily Didymictinae within extinct family Viverravidae, that lived in North America and Europe from the late Paleocene to middle Eocene.
Galecyon ("polecat-dog") is an extinct genus of placental mammals from extinct order Hyaenodonta, that lived in Europe and North America during the early Eocene.
Hyaenodonta is an extinct order of hypercarnivorous placental mammals of clade Pan-Carnivora from mirorder Ferae. Hyaenodonts were important mammalian predators that arose during the early Paleocene in Europe and persisted well into the late Miocene.
Tytthaena is an extinct genus of placental mammals from extinct subfamily Tytthaeninae within extinct family Oxyaenidae, that lived in North America from the late Paleocene to early Eocene.
Machaeroidinae ("dagger-like") is an extinct subfamily of carnivorous sabre-toothed placental mammals from extinct family Oxyaenidae, that lived from the early to middle Eocene of Asia and North America. Traditionally classified as hyaenodonts, this group is now classified as a member of the family Oxyaenidae.
Metapterodon is an extinct genus of hyainailourid hyaenodonts of the subfamily Hyainailourinae, that lived in Africa during the early Oligocene to early Miocene. Fossils of Metapterodon were recovered from the Egypt, Uganda, Elisabeth Bay Formation in Namibia, and Rusinga Island and Karungu in Kenya.
Wyonycteris is a genus of small mammals that existed in the late Paleocene and early Eocene epochs. The type species is Wyonycteris chalix, which lived in Wyoming during the Clarkforkian North American Land Mammal Age of the Paleocene and was originally proposed to be an early form of insectivorous bat. Later re-examination of the material has put this alliance in doubt, and the genus has instead been proposed as belonging to the subfamily Placentidentinae, within the family Nyctitheriidae. Similar fossil material of the same time period found in Europe was later discovered and described as new species, Wyonycteris richardi.
Protictis is an extinct paraphyletic genus of placental mammals from extinct subfamily Didymictinae within extinct family Viverravidae, that lived in North America from early Paleocene to middle Eocene.
Oxyaeninae is an extinct subfamily of placental mammals from extinct family Oxyaenidae, that lived in Asia, North America and Europe from the late Paleocene to middle Eocene.
Palaeonictinae is an extinct subfamily of placental mammals from extinct family Oxyaenidae, that lived from the late Paleocene to early Eocene of Europe and North America.