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Pelagiarctos
''Pelagiarctos'' was a genus of walrus that lived during the Mid Miocene, approx. 13-15 mya. Its remains have been found in the Sharktooth Hill Bonebed, in Kern County, California. It was originally described as an Otariidae, though it is now usually considered to be a basal Odobenidae. Anatomy To date, the only material of ''Pelagiarctos'' that has been found includes a handful of partial mandibles. The mandibles themselves are approximately the same size as those of the contemporaneous pinniped '' Allodesmus kernensis'', but differ in that the cheek teeth have two roots (instead of one, as in ''Allodesmus'') and that the dentary itself is much thicker. They are also highly vascularized and covered in unusually large mental foramina, indicating that ''Pelagiarctos'' may have had somewhat fleshy lips. The cheek teeth resemble those of several terrestrial carnivores, specifically borophagine dogs and hyaenids. This, coupled with the robust dentary, indicates that ''Pelagiarctos' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odobenid
Odobenidae is a family of pinnipeds. The only living species is the walrus (''Odobenus rosmarus''). In the past, however, the group was much more diverse, and includes more than a dozen fossil genera. Taxonomy All genera, except ''Odobenus'', are extinct. *†''Archaeodobenus'' *†''Prototaria'' *†''Proneotherium'' *†'' Nanodobenus'' *†''Neotherium'' *†''Imagotaria'' *†''Kamtschatarctos'' *†''Pelagiarctos'' *†''Pontolis'' *†'' Pseudotaria'' *†''Titanotaria'' *Clade Neodobenia **†''Gomphotaria'' **Subfamily Dusignathinae ***†'' Dusignathus'' **Subfamily Odobeninae ***†''Aivukus'' ***†''Ontocetus'' ***†''Pliopedia'' ***†'' Protodobenus'' ***†''Valenictus'' ***''Odobenus The walrus (''Odobenus rosmarus'') is a large flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in the fami ...'' In re-analyzing ''Pelagiar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharktooth Hill
The Temblor Formation is a geologic formation in California. It preserves fossils dating back from the Late Oligocene to the Middle Miocene of the Neogene period. It is notable for the famous Sharktooth Hill deposit (otherwise known as Ernst Quarry). Fossils Vertebrates Cartilagenous fishes = Sharks = * '' Carcharias'' * ''Cephaloscyllium'' * ''Cetorhinus'' * †''Carcharocles megalodon'' Boessenecker, Ehret, D, Long, D, Churchill, M, Martin, E, Boessenecker, S. The Early Pliocene extinction of the mega-toothed shark ''Otodus megalodon'': a view from the eastern north Pacific. PeerJ. 2019 Feb 13;7:e6088. doi: 10.7717/peerj.6088. eCollection 2019. * †''Galeocerdo aduncus'' * †''Hemipristis serra'' * '' Heterodontus'' * ''Hexanchus'' * †'' Isurus desori'' * †'' Isurus hastalis'' * †''Isurus planus''Malchow, A. 2009. MIOCENE SHARK TOOTH HILL LOCALITY, KERN COUNTY, CALIFORNIA. Geological Society of America North-Central Section - 43rd Annual Meeting (2-3 April 2009) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnivores
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other soft tissues) whether through hunting or scavenging. Nomenclature Mammal order The technical term for mammals in the order Carnivora is ''carnivoran'', and they are so-named because most member species in the group have a carnivorous diet, but the similarity of the name of the order and the name of the diet causes confusion. Many but not all carnivorans are meat eaters; a few, such as the large and small cats (felidae) are ''obligate'' carnivores (see below). Other classes of carnivore are highly variable. The Ursids, for example: While the Arctic polar bear eats meat almost exclusively (more than 90% of its diet is meat), almost all other bear species are omnivorous, and one species, the giant panda, is nearly exclusively herbivorous. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puffinus
''Puffinus'' is a genus of seabirds in the order Procellariiformes that contains about 20 small to medium-sized shearwaters. Two other shearwater genera are named: ''Calonectris'', which comprises three or four large shearwaters, and ''Ardenna'' with another seven species (formerly often included within ''Puffinus''). The taxonomy of this group is the cause of much debate, and the number of recognised species varies with the source. The species in this group are long-winged birds, dark brown or black above, and white to dark brown below. They are pelagic outside the breeding season. They are most common in temperate and cold waters. These tubenose birds fly with stiff wings, and use a shearing flight technique to move across wave fronts with the minimum of active flight. Some small species, such as the Manx shearwater, are cruciform in flight, with their long wings held directly out from their bodies. Many are long-distance migrants, perhaps most spectacularly the sooty and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteodontornis
''Osteodontornis'' is an extinct seabird genus. It contains a single named species, ''Osteodontornis orri'' (Orr's bony-toothed bird, in literal translation of its scientific name), which was described quite exactly one century after the first species of the Pelagornithidae ('' Pelagornis miocaenus'') was. ''O. orri'' was named after then-recently deceased naturalist Ellison Orr. The bony-toothed or pseudotooth birds were initially believed to be related to albatrosses in the Procellariiformes, but actually they seem to be rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty. Also, their internal taxonomy is not well-resolved. An earlier-described pseudotooth bird, ''Cyphornis magnus'' from Vancouver Island (Canada), was believed to be of Eocene age but is nowadays assumed to have lived about twenty million years ago in the Early Miocene, not too long before the Clarendonian ( M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psephophorus
''Psephophorus'' is an extinct genus of sea turtle that lived from the Oligocene to the Pliocene. Its remains have been found in Europe, Africa, North America, and New Zealand. It was first named by Hermann von Meyer in 1847, and contains seven species, ''P. polygonus'', ''P. calvertensis'', ''P. eocaenus'', ''P. oregonesis'', ''P. californiensis'', ''P. rupeliensis'',''Proceedings''; page 8. By the Zoological Society of London; published 1891. Retrieved on June 28th, 2008. ''P. scaldii'', and a species discovered in 1995, ''P. terrypratchetti''. ''Psephophorus'' is the only Miocene dermochelyid turtle found in Europe. One species of ''Psephophorus'' could measure up to ten feet in length. Discovery and identification Von Meyer originally named ''Psephophorus'' in 1846. At first he was unable to identify the creature beyond its dermal plates, but when he later received a drawing he was able to describe the specimen, which was then in Pressburg, as a fragment of a carapace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcharocles
''Otodus'' is an extinct genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name ''Otodus'' comes from Ancient Greek (, meaning "ear") and (, meaning "tooth") – thus, "ear-shaped tooth". Anatomy This shark is known from its fossilized teeth and vertebral centra. Like other elasmobranchs, the skeleton of ''Otodus'' was composed of cartilage and not bone, resulting in relatively few preserved skeletal structures appearing within the fossil record. The teeth of this shark are large with triangular crown, smooth cutting edges, and visible cusps on the roots. Some ''Otodus'' teeth also show signs of evolving serrations. Size estimation The fossils of ''Otodus'' indicate that it was a very large macro-predatory shark. The largest known teeth measure about in height. The vertebral centrum of this shark are over 12.7 cm (5 inch) wide. Scientists suggest that this shark at least reached in total length (TL), with a maximum length of . Distr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphyrna
''Sphyrna'' (from the Greek word σφῦρα, "hammer") is a genus of hammerhead sharks with a cosmopolitan distribution in the world's oceans. Members of ''Sphyrna'' have a tendency to inhabit coastal waters along the intertidal zone rather than the open ocean, as their prey such as invertebrates, fish, rays, small crustaceans, and other benthic organisms hide in the sands and sediment along these zones. Members of ''Sphyrna'' are also known by synonyms such as ''Zygaena'', ''Cestracion'', and ''Sphyrichthys''. The earliest species described of this genus was ''Sphyrna zygaena'' by Carl Linnaeus in 1758, while the latest described member, '' Sphyrna gilberti'', was discovered and described in 2013. Species The recognized species in this genus are:Martin, R. Aidan. (February 24, 1998)Recent Changes in Hammerhead Taxonomy ''ReefQuest Centre for Shark Research''. Retrieved on October 18, 2008. ;Extant * '' Sphyrna corona'' ( S. Springer, 1940) (scalloped bonnethead) * '' Sphyrn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isurus
''Isurus'' is a genus of mackerel sharks in the family Lamnidae, commonly known as the mako sharks. Description The two living species are the common shortfin mako shark (''I. oxyrinchus'') and the rare longfin mako shark (''I. paucus''). They range in length from , and have an approximate maximum weight of . They both have a distinctive blue-gray color scheme common among mackerel sharks. Several extinct species are known from fossils found in sediments from the Cretaceous to the Quaternary (age range: 99.7 to 0.781 million years ago). The family Lamnidae also includes the great white shark and the porbeagle. Mako sharks are capable of swimming at speeds up to . The great white shark is also closely related to an ancient mako shark species, ''Isurus hastalis''. However, fossil evidence suggests ''I. hastalis'', like the great white shark, also belonged to the genus ''Carcharodon''. Species The genus contains these species: * '' Isurus oxyrinchus'' (Rafinesque, 1810) (shortfi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continents of Asia and Oceania in the west and the Americas in the east. At in area (as defined with a southern Antarctic border), this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of Earth's water surface and about 32% of its total surface area, larger than Earth's entire land area combined .Pacific Ocean . '' Britannica Concise.'' 2008: Encyclopædia Britannica, Inc. The centers of both the |
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