| Cophocetus | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | † Pelocetidae |
| Genus: | † Cophocetus Packard and Kellogg, 1934 |
| Species | |
| |
Cophocetus is an extinct genus of baleen whale known from Miocene-aged marine strata in Oregon, North America. [1] [2] [3]
The blue whale is a marine mammal belonging to the baleen whale parvorder Mysticeti. Reaching a maximum confirmed length of 29.9 metres (98 ft) and weighing up to 199 tonnes, it is the largest animal known to have ever existed. The blue whale's long and slender body can be various shades of greyish-blue dorsally and somewhat lighter underneath.
The Mustelidae are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids are a diverse group and form the largest family in the order Carnivora, suborder Caniformia. They comprise about 56–60 species across eight subfamilies.
The Miocene is the first geological epoch of the Neogene Period and extends from about 23.03 to 5.333 million years ago (Ma). The Miocene was named by Scottish geologist Charles Lyell; its name comes from the Greek words μείων and καινός and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene is preceded by the Oligocene and is followed by the Pliocene.
The Pliocene Epoch is the epoch in the geologic timescale that extends from 5.333 million to 2.58 million years BP. It is the second and most recent epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch. Prior to the 2009 revision of the geologic time scale, which placed the four most recent major glaciations entirely within the Pleistocene, the Pliocene also included the Gelasian Stage, which lasted from 2.588 to 1.806 million years ago, and is now included in the Pleistocene.
The Desmostylia are an extinct order of aquatic mammals that existed from the early Oligocene (Rupelian) to the late Miocene (Tortonian).
Menoceras is a genus of extinct, small rhinoceros endemic to most of southern North America and ranged as far south as Panama during the early Miocene epoch. It lived from around 30.7—19.7 Ma, existing for approximately 11 million years.
Balaena is a genus of cetacean (whale) in the family Balaenidae. Balaena is considered a monotypic genus, as it has only a single extant species, the bowhead whale. It was named in 1758 by Linnaeus, who at the time considered all of the right whales as a single species. Historically, both the family Balaenidae and genus Balaena were known by the common name, "right whales", however Balaena are now known as bowhead whales.
Megalonychidae is a group of sloths including the extinct Megalonyx. Megalonychids first appeared in the early Oligocene, about 35 million years (Ma) ago, in southern Argentina (Patagonia). There is actually one possible find dating to the Eocene, about 40 Ma ago, on Seymour Island in Antarctica. They first reached North America by island-hopping across the Central American Seaway, about 9 million years ago, prior to formation of the Isthmus of Panama about 2.7 million years ago. Some megalonychid lineages increased in size as time passed. The first species of these were small and may have been partly tree-dwelling, whereas the Pliocene species were already approximately half the size of the huge Late Pleistocene Megalonyx jeffersonii from the last ice age.
Daeodon is an extinct genus of entelodont artiodactyl that inhabited North America about 23 to 20 million years ago during the latest Oligocene and earliest Miocene. The type species is Daeodon shoshonensis, described by a very questionable holotype by Cope. Some authors synonimize it with Dinohyus hollandi and several other species, but due to the lack of diagnostic material, this is questionable at best.
Parictis is an extinct arctoid, possibly the earliest genus of bears known. Though a recent variety of morphological evidence links amphicynodontines with pinnipeds. It was a very small and graceful arctoid with a skull only 7 cm long. Parictis first appeared in North America in the Late Eocene, but it did not arrive in Eurasia until the Miocene. Some suggest that Parictis may have emigrated from Asia into North America during the major sea level low about 37 mya, because of the continued evolution of the Amphicynodontinae into the Hemicyoninae in Asia. Although no Parictis fossils have been found in East Asia, Parictis does appear in Eurasia and Africa, but not until the Miocene.
Kolponomos is an extinct genus of carnivoran mammal that existed in the Late Arikareean North American Land Mammal Age, early Miocene epoch, about 20 million years ago. It was likely a marine mammal. The genus was erected in 1960 by Ruben A. Stirton, a paleontologist at the University of California Museum of Paleontology, Berkeley, for the species K. clallamensis, on the basis of a partial skull and jaw found on the Olympic Peninsula. At the time, Stirton questionably assigned it to Procyonidae, its systematic position remained problematic until the discovery of more fossils including a nearly complete cranium from the original locality of K. clallamensis which helped identify it as part of the group from which pinnipeds evolved.
Aulophyseter is an extinct genus of sperm whales from the Miocene formations of the west and east coasts of North America.
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.
Xenastrapotherium is an extinct genus of astrapothere, a type of hoofed herbivorous mammal, native to South America, which lived in the Middle to Late Miocene period, typically during the Laventan stage. It is a member of the family Astrapotheriidae in the subfamily Uruguaytheriinae, large astrapotheres, equipped with a trunk-like nose and protruding teeth, similar to the elephants, but their tusks were the canine teeth, not the incisors. Xenastrapotherium was a genus widely distributed in northern South America, in contrast to other species of astrapotheres which lived in the area of the Southern Cone of the continent. It differed from other astrapotheres by having two lower incisors on each side of the jaw and the tusks have a pronounced longitudinal curvature, although their general shape and size are probably very similar to Astrapotherium, whose weight would be 900 to 1,500 kilograms, comparable to the current black rhino.
Paleontology in Oregon refers to paleontological research occurring within or conducted by people from the U.S. state of Oregon. Oregon's geologic record extends back approximately 400 million years ago to the Devonian period, before which time the state's landmass was likely submerged under water. Sediment records show that Oregon remained mostly submerged until the Paleocene period. The state's earliest fossil record includes plants, corals, and conodonts. Oregon was covered by seaways and volcanic islands during the Mesozoic era. Fossils from this period include marine plants, invertebrates, ichthyosaurs, pterosaurs, and traces such as invertebrate burrows. During the Cenozoic, Oregon's climate gradually cooled and eventually yielded the environments now found in the state. The era's fossils include marine and terrestrial plants, invertebrates, fish, amphibians, turtles, birds, mammals, and traces such as eggs and animal tracks.
Mixocetus is a genus of extinct baleen whale belonging to the family Tranatocetidae. It is known only from the late Miocene (Tortonian) of Los Angeles County, California.
Metopocetus is an extinct genus of baleen whale belonging to the family Cetotheriidae. The type species is Metopocetus durinasus.
Pelocetus is an extinct genus of baleen whale, belonging to the family Pelocetidae. Fossils have been found in Miocene-aged marine strata in North America.
Idiophyseter is a genus of macroraptorial sperm whale from the Miocene. Its fossils have been found in Templeton California. Idiophyseter was small in size compared to modern genera and its maxilla has single-rooted alveoli. It lacked ventral internal process of the sort present in the modern day genus of sperm whale (Physeter).
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