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Altanius
''Altanius'' is a genus of extinct primates found in the early Eocene of Mongolia. Though its phylogenetic relationship is questionable, many have placed it as either a primitive omomyid or as a member of the sister group to both adapoids and omomyids. The genus is represented by one species, ''Altanius orlovi'', estimated to weigh about 10–30g from relatively well-known and complete dental and facial characteristics. Morphology Much of the fossilized remains of ''Altanius'', as with any extinct vertebrate, are isolated teeth fragments. However, an abundance of specimens, collected between Dashzeveg and McKenna's initial discovery of the species in 1977 and the present, have yielded an almost complete dentition. Identifying dental characteristics of the genus include small, high, trigonids, the anterior basin on lower molars, and high premolars. It is linked with the omomyoid group in its unfused mandible, reduced paraconids on the lower molars, and overall shorter mola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omomyid
Omomyidae is a group of early primates that radiated during the Eocene epoch between about (mya). Fossil omomyids are found in North America, Europe & Asia making it one of two groups of Eocene primates with a geographic distribution spanning holarctic continents, the other being the adapids (family Adapidae). Early representatives of the Omomyidae and Adapidae appear suddenly at the beginning of the Eocene (56 mya) in North America, Europe, and Asia, and are the earliest known crown primates. Etymology The Omomyidae are named after the type genus '' Omomys''. While the etymology of this genus is uncertain, it most likely derives from the Ancient Greek ὠμός (ōmós), "raw, crude" + μῦς (mûs), "mouse". Characteristics Features that characterize many omomyids include large orbits (eye sockets), shortened rostra and dental arcades, loss of anterior premolars, cheek teeth adapted for insectivorous or frugivorous diets, and relatively small body mass (i.e., less than 500 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1977 In Paleontology
Plants Ferns and fern allies Conifers Angiosperms Invertebrates Mollusks Conodonts Fish Archosauriformes Non-avian dinosaurs Data courtesy of George Olshevsky's dinosaur genera list. Birds Pterodactyls Expeditions, field work, and fossil discoveries * Trexler found hadrosaur remains west of Choteau, Montana in strata of the Two Medicine Formation. Popular culture Literature * ''The Year of the Dinosaur'' Edwin H. Colbert and illustrated by his wife, Margaret was published. This story describes a year in the life of a "brontosaur" and was an attempt to educate the reader about prehistory through a fictional portrayal of it. References {{Reflist, refs= {{cite book, last=Sarjeant , first=W. A. S. , year=2001 , chapter=Dinosaurs in fiction , title=Mesozoic Vertebrate Life , editor1-last=Tanke , editor1-first=D. H. , editor2-last=Carpenter , editor2-first= K. , publisher=Indiana University Press , pages=504–529 Paleontology Paleontology (), also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carpolestidae
Carpolestidae is a family of primate-like Plesiadapiformes that were prevalent in North America and Asia from the mid Paleocene through the early Eocene. Typically, they are characterized by two large upper posterior premolars and one large lower posterior premolar. They weighed about 20-150g, and were about the size of a mouse. Though they come from the order, Plesiadapiformes, that may have given rise to the primate order, carpolestids are too specialized and derived to be ancestors of primates. Historically, the almost twenty species included within the family were thought to have given rise to each other over time in a linear and straightforward manner. Still today it is widely assumed that '' Elphidotarsius'' from the mid to late Paleocene gave rise to ''Carpodaptes'' which lived in the late Paleocene and subsequently gave rise to ''Carpolestes'' from the early Eocene. As a result, they have been used as biostratigraphic indicators in a variety of paleontological digs. Howeve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Primate Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Talonid
The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth", from ''mola'', millstone and ''dens'', tooth. Molars show a great deal of diversity in size and shape across mammal groups. The third molar of humans is sometimes vestigial. Human anatomy In humans, the molar teeth have either four or five cusps. Adult humans have 12 molars, in four groups of three at the back of the mouth. The third, rearmost molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the front of the gum at about the age of 20, although this varies from individual to individual. Race can also affect the age at which this occurs, with statistical variations between groups. In some cases, it may not even erupt at all. The human mouth contains upper (maxillary) and lower (mandibul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lingual Cusp
{{disambig ...
Lingual may refer to: * Tongue, a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication * Lingual, in palaeontology, the side of the teeth that faces the tongue * Lingual artery arises from the external carotid between the superior thyroid and facial artery * Lingual veins begin on the dorsum, sides, and under surface of the tongue, and, passing backward along the course of the lingual artery, end in the internal jugular vein * Lingual gyrus of the occipital lobe lies between the calcarine sulcus and the posterior part of the collateral sulcus * Lingual bone * Lingual nerve, a branch of the mandibular nerve * HTLINGUAL HTLINGUAL (also HGLINGUAL), a secret project of the United States of America's Central Intelligence Agency (CIA) to intercept mail destined for the Soviet Union and China, operated from 1952 until 1973. Originally known under the codename SRPOIN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cantius
''Cantius'' is a genus of adapiform primates from the early Eocene of North America and Europe. It is extremely well represented in the fossil record in North America and has been hypothesized to be the direct ancestor of Notharctus in North America. The evolution of Cantius is characterized by a significant increase in body mass that nearly tripled in size. The earliest species were considered small-sized and weighed in around 1 kg, while the later occurring species were considered medium-sized and likely weighed in around 3 kg. Though significantly smaller, the fossil remains discovered of the various species of Cantius have striking similarities to that of Nothartcus and Smilodectes. It is likely Cantius relied on arboreal quadrupedal locomotion, primarily running and leaping. This locomotor pattern comparable to that of extant lemurs, which has fostered the hypothesis that Cantius and other strepsirrhine adapiforms may have a close phylogenetic affinity to living lemu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiadapiformes
Plesiadapiformes (" Adapid-like" or "near Adapiformes") is a group of Primates, a sister of the Dermoptera. While none of the groups normally directly assigned to this group survived, the group appears actually not to be literally extinct (in the sense of having no living descendants) as the remaining primates (the crown primates or "Euprimates") appear to be derived Plesiadapiformes, as a sister of e.g. the Carpolestidae. The term Plesiadapiformes may still be used for all primates which are not crown primates, but this usage is paraphyletic. When the crown primates are cladistically granted, it becomes an obsolete junior synonym to primates. ''Purgatorius'' is believed to be a basal Plesiadapiformes. Plesiadapiformes first appear in the fossil record between 65 and 55 million years ago, although many were extinct by the beginning of the Eocene. They may have been the first mammals to have finger nails in place of claws. In 1990, K.C. Beard attempted to link the Plesiadapiforme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Evolution
Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.Zhang, J. and Kumar, S. 1997Detection of convergent and parallel evolution at the amino acid sequence level. ''Mol. Biol. Evol.'' 14, 527-36. Parallel vs. convergent evolution Given a particular trait that occurs in each of two lineages descended from a specified ancestor, it is possible in theory to define parallel and convergent evolutionary trends strictly, and distinguish them clearly from one another. However the criteria for defining convergent as opposed to parallel evolution often are unclear in practice, so that arbitrary diagnosis is common in some cases. When two species are similar in a particular character, evolution is defined as parallel if the ancestors shared that similarity; if they did not, the evolution of that character in those species is defined as convergent. However, thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Popigai impact structure, Siberia and in what is now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
