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Eucynodontia
Eucynodontia ("true dog teeth") is a clade of cynodont therapsids including mammals and most non-mammalian cynodonts. The oldest eucynodonts are known from the Early Triassic and possibly Late Permian. Eucynodontia includes two major subgroups, Cynognathia and Probainognathia. The clade was named in 1982 by Thomas Kemp, who defined it as all cynodonts more derived than ''Thrinaxodon''. In 2001, Hopson and Kitching redefined the clade Eucynodontia as the least inclusive group containing Mammalia and ''Exaeretodon ''Exaeretodon'' is an extinct genus of fairly large, low-slung traversodontid cynodonts from the southern parts of Pangea. Four species are known, from various formations. ''E. argentinus'' is from the Carnian-age (Late Triassic) Cancha de Boch ...''.James A. Hopson and James W. Kitching, 2001, "A Probainognathian Cynodont from South Africa and the Phylogeny of Nonmammalian Cynodonts" pp 5-35 in: PARISH A. JENKINS, JR., MICHAEL D. SHAPIRO, AND TOMASZ OWERKOWICZ, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brasilitherium Riograndensis
''Brasilodon'' ("tooth from Brazil") is an extinct genus of small, mammal-like cynodonts that lived in what is now Brazil during the Norian age of the Late Triassic epoch, about 225.42 million years ago. While no complete skeletons have been found, the length of ''Brasilodon'' has been estimated at around . Its dentition shows that it was most likely an insectivore. The genus is monotypic, containing only the species ''B. quadrangularis''. ''Brasilodon'' belongs to the family Brasilodontidae, whose members were some of the closest relatives of mammals, the only cynodonts alive today. Two other brasilodontid genera, ''Brasilitherium'' and ''Minicynodon'', are now considered to be junior synonyms of ''Brasilodon''. Discovery and naming The first three specimens referred to ''Brasilodon quadrangularis'' were found at the Linha São Luiz site, a quarry near the town of Faxinal do Soturno in the state of Rio Grande do Sul. The rocks where ''Brasilodon'' was found belong to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynodonts
The cynodonts () (clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variety of lifestyles, including carnivory and herbivory. Mammals are cynodonts, as are their extinct ancestors and close relatives, having evolved from advanced probainognathian cynodonts during the Late Triassic. All other cynodont lines went extinct, with the last known non-mammalian cynodont group, the Tritylodontidae, having its youngest records in the Early Cretaceous. Description Early cynodonts have many of the skeletal characteristics of mammals. The teeth were fully differentiated and the braincase bulged at the back of the head. Outside of some crown-group mammals (notably the therians), all cynodonts probably laid eggs. The temporal fenestrae were much larger than those of their ancestors, and the widening of the zygomatic arch in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probainognathia
Probainognathia is one of the two major subgroups of the clade Eucynodontia, the other being Cynognathia. The earliest forms were carnivorous and insectivorous, though some groups eventually also evolved herbivorous diets. The earliest and most basal probainognathian is the Middle Triassic (Anisian) aged ''Lumkuia'', from South Africa, though probainognathians would not become prominent until the mid Norian stage of the Late Triassic. Three groups survived the extinction at the end of Triassic: Tritheledontidae and Tritylodontidae, which both survived until the Jurassic—the latter even into the Cretaceous (''Montirictus'' and '' Xenocretosuchus'')—and Mammaliaformes, which includes the mammals. Phylogeny Below is a cladogram from Ruta, Botha-Brink, Mitchell and Benton (2013) showing one hypothesis of cynodont relationships: See also * Evolution of mammals * List of prehistoric mammals This is an incomplete list of prehistoric mammals. It does not include extant mam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynodont
The cynodonts () (clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variety of lifestyles, including carnivory and herbivory. Mammals are cynodonts, as are their extinct ancestors and close relatives, having evolved from advanced probainognathian cynodonts during the Late Triassic. All other cynodont lines went extinct, with the last known non-mammalian cynodont group, the Tritylodontidae, having its youngest records in the Early Cretaceous. Description Early cynodonts have many of the skeletal characteristics of mammals. The teeth were fully differentiated and the braincase bulged at the back of the head. Outside of some crown-group mammals (notably the therians), all cynodonts probably laid eggs. The temporal fenestrae were much larger than those of their ancestors, and the widening of the zygomatic arch in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrinaxodon
''Thrinaxodon'' is an extinct genus of cynodonts, most commonly regarded by its species ''T. liorhinus'' which lived in what are now South Africa and Antarctica during the Early Triassic. ''Thrinaxodon'' lived just after the Permian–Triassic mass extinction event, its survival during the extinction may have been due to its burrowing habits. Similar to other therapsids, ''Thrinaxodon'' adopted a semi-sprawling posture, an intermediary form between the sprawling position of basal tetrapods (still observed modern Crocodilia) and the more upright posture present in current mammals.Blob R. 2001. Evolution of hindlimb posture in non-mammalian therapsids: biomechanical tests of paleontological hypotheses. 27(1): 14-38. ''Thrinaxodon'' is prevalent in the fossil record in part because it was one of the few carnivores of its time, and was of a larger size than similar cynodont carnivores. Description ''Thrinaxodon'' was a small synapsid roughly the size of a fox and possibly covered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynognathia
Cynognathia ("dog jaw") is one of two major clades of cynodonts, the other being Probainognathia. Cynognathians included the large carnivorous genus ''Cynognathus'' and the herbivorous traversodontids. Cynognathians can be identified by several synapomorphies including a very deep zygomatic arch that extends above the middle of the orbit. Cynognathian fossils are currently known from Africa, Antarctica, Asia, Europe, North America and South America. Taxonomy *Suborder Cynodontia **Infraorder Eucynodontia ***(unranked) Cynognathia ****Family Cynognathidae *****''Cynognathus'' ****(unranked) Gomphodontia *****Family Diademodontidae ******''Diademodon'' ******'' Titanogomphodon'' *****(unranked) Neogomphodontia ******Family Trirachodontidae *******Subfamily Trirachodontinae ********''Langbergia'' ********'' Trirachodon'' *******Subfamily Sinognathinae ********''Beishanodon'' ********'' Sinognathus'' ********''Cricodon'' ******Family Traversodontidae *******'' Etjoia'' *******'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithorhynchus Anatinus
The platypus (''Ornithorhynchus anatinus''), sometimes referred to as the duck-billed platypus, is a semiaquatic, egg-laying mammal endemic to eastern Australia, including Tasmania. The platypus is the sole living representative or monotypic taxon of its family (Ornithorhynchidae) and genus (''Ornithorhynchus''), though a number of related species appear in the fossil record. Together with the four species of echidna, it is one of the five extant species of monotremes, mammals that lay eggs instead of giving birth to live young. Like other monotremes, it senses prey through electrolocation. It is one of the few species of venomous mammals, as the male platypus has a spur on the hind foot that delivers a venom, capable of causing severe pain to humans. The unusual appearance of this egg-laying, duck-billed, beaver-tailed, otter-footed mammal baffled European naturalists when they first encountered it, and the first scientists to examine a preserved platypus body (in 1799) ju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therapsid
Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more underneath the body, as opposed to the sprawling posture of many reptiles and salamanders. Therapsids evolved from "pelycosaurs", specifically within the Sphenacodontia, more than 279.5 million years ago. They replaced the "pelycosaurs" as the dominant large land animals in the Middle Permian through to the Early Triassic. In the aftermath of the Permian–Triassic extinction event, therapsids declined in relative importance to the rapidly diversifying reptiles during the Middle Triassic. The therapsids include the cynodonts, the group that gave rise to mammals ( Mammaliaformes) in the Late Triassic, around 225 million years ago. Of the non-mammalian therapsids, only cynodonts survived beyond the end of the Triassic, with the only other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exaeretodon
''Exaeretodon'' is an extinct genus of fairly large, low-slung traversodontid cynodonts from the southern parts of Pangea. Four species are known, from various formations. ''E. argentinus'' is from the Carnian-age (Late Triassic) Cancha de Bochas Member of the Ischigualasto Formation in the Ischigualasto-Villa Unión Basin in northwestern Argentina. ''E. major'' and ''E. riograndensis'' are from the Carnian-age portion of the Santa Maria Formation of the Paraná Basin in southeastern Brazil. ''E. statisticae'' is from the Carnian-age Lower Maleri Formation of India. Description This genus was an herbivore up to long, with a specialized grinding action when feeding. An analysis of the size of the bones of calves collected in Paleorrota concluded that the mother ''Exaeretodon'' had one or two calves, for one pregnancy. Taxonomy When he first named the species, Argentine paleontologist José Bonaparte mentioned several features that distinguish it from all other traverso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammalia
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Kitching
James William Kitching (6 February 1922 – 24 December 2003) was a South African vertebrate palaeontologist and regarded as one of the world’s greatest fossil finders. Career His work in the southern hemisphere, including Antarctica, led to the establishment of one of the world's finest fossil collections, housed at the Bernard Price Institute for Palaeontological Research (BPI) in Johannesburg.University of the Witwatersrand, Johannesburg, Bernard Price Institute He contributed greatly to the palaeontology of southern |
James Hopson
James Allen Hopson (born 1935) is an American paleontologist and professor (now retired) at the University of Chicago. His work has focused on the evolution of the synapsids (a group of amniotes that includes the mammals), and has been focused on the transition from basal synapsids to mammals, from the late Paleozoic through the Mesozoic Eras. He received his doctorate at Chicago in 1965, and worked at Yale before returning to Chicago in 1967 as a faculty member in Anatomy, and has also been a research associate at the Field Museum of Natural History since 1971. He has also worked on the paleobiology of dinosaurs, and his work, along with that of Peter Dodson Peter Dodson (born August 20, 1946) is an American paleontologist who has published many papers and written and collaborated on books about dinosaurs. An authority on Ceratopsians, he has also authored several papers and textbooks on hadrosaurs a ..., has become a foundation piece for the modern understanding of duc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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