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Pantolambdoidea
Pantodonta is an extinct suborder (or, according to some, an order) of eutherian mammals. These herbivorous mammals were one of the first groups of large mammals to evolve (around 66 million years ago) after the end of the Cretaceous. The last pantodonts died out at the end of the Eocene (around 34 million years ago). Pantodonta include some of the largest mammals of their time, but were a diversified group, with some primitive members weighing less than and the largest more than . The earliest and most primitive pantodonts, '' Bemalambda'' (with a skull probably the size of a dog) and '' Hypsilolambda'', appear in the early Paleocene Shanghuan Formation in China. All more derived families are collectively classified as Eupantodonta. The pantodonts appear in North America in the middle Paleocene, where ''Coryphodon'' survived into the middle Eocene. Pantodont teeth have been found in South America (''Alcidedorbignya'') and Antarctica, and footprints in a coal mine on Svalb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact (Chicxulub impact) and possibly volcanism (Deccan Traps), marked the beginning of the Paleocene and killed off 75% of species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three Evolution of mammalian auditory ossicles, middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors Genetic divergence, diverged in the Carboniferous Period over 300 million years ago. Around 6,640 Neontology#Extant taxon, extant species of mammals have been described and divided into 27 Order (biology), orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, Mole (animal), moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the Artiodactyl, even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including Felidae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel Phenotypic trait, character or character state that has evolution, evolved from its ancestral form (or Plesiomorphy and symplesiomorphy, plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxon, taxa and is therefore Hypothesis#Scientific hypothesis, hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies Homology (biology), homology. Examples of apomorphy are the presence of Terrestrial locomotion#Posture, erect gait, fur, Evolution of mammalian auditory ossicles, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a Terrestrial locomotion#Posture, sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dental Formula
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology (that is, the relationship between the shape and form of the tooth in question and its inferred function) of the teeth of an animal. Terminology Animals whose teeth are all of the same type, such as most non-mammalian vertebrates, are said to have '' homodont'' dentition, whereas those whose teeth differ morphologically are said to have '' heterodont'' dentition. The dentition of animals with two successions of teeth (deciduous, permanent) is referred to as '' diphyodont'', while the dentition of animals with only one set of teeth throughout life is ''monophyodont''. The dentition of animals in which the teeth are continuously discarded and replaced throughout life is termed ''polyphyodont''. The dentition of animals in which the teeth a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Sloth
Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. They varied widely in size with the largest, belonging to genera '' Lestodon'', ''Eremotherium'' and ''Megatherium'', being around the size of elephants. Ground sloths represent a paraphyletic group, as living tree sloths are thought to have evolved from ground sloth ancestors. The early evolution of ground sloths took place during the late Paleogene and Neogene of South America, while the continent was isolated. At their earliest appearance in the fossil record, they were already distinct at the family level. Sloths dispersed into the Greater Antilles during the Oligocene, and the presence of intervening islands between the American continents in the Miocene allowed a dispersal of some species into North America. They were hardy as evidenced by their high species diversity and their presence in a wide variety of environments, extending from the far south of Patagonia ( Cueva del Milodón ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Svalbard
Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norway, Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. North of continental Europe, mainland Europe, it lies about midway between the northern coast of Norway and the North Pole. The islands of the group range from 74th parallel north, 74° to 81st parallel north, 81° north latitude, and from 10th meridian east, 10° to 35th meridian east, 35° east longitude. The largest island is Spitsbergen (37,673 km2), followed in size by Nordaustlandet (14,443 km2), (5,073 km2), and Barentsøya (1,288 km2). Bear Island (Norway), Bjørnøya or Bear Island (178 km2) is the most southerly island in the territory, situated some 147 km south of Spitsbergen. Other small islands in the group include Hopen (Svalbard), Hopen to the southeast of Edgeøya, Kongsøya and Svenskøya in the east, and Kvitøya to the northeast. The largest settlement is Longyearbyen, situated in Isfjor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coryphodon
''Coryphodon'' (from Greek , "point", and , "tooth", meaning ''peaked tooth'', referring to "the development of the angles of the ridges into points [on the molars].") is an extinct genus of pantodonts of the family Coryphodontidae. ''Coryphodon'' was a pantodont, a member of the world's first group of large browsing mammals. It migrated across what is now northern North America, replacing ''Barylambda'', an earlier pantodont. It is regarded as the ancestor of the genus ''Hypercoryphodon'' of Late Eocene Mongolia. ''Coryphodon'' is known from many specimens in North America and considerably fewer in Europe, Mongolia, and China. It is a small to medium-sized coryphodontid which differs from other members of the family in dental characteristics. Description At about at shoulder height and in body length, ''Coryphodon'' is one of the largest-known mammals of its time. The creature was very slow, with long upper limbs and short lower limbs, which were needed to support its weig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
