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Probainognathians
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 mammals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aleodon
''Aleodon'' is an extinct genus of cynodonts that lived from the Middle to the Late Triassic. Relatively few analyses have been conducted to identify the phylogenetic placement of ''Aleodon'', however those that have place ''Aleodon'' as a sister taxon to '' Chiniquodon''. Two species of ''Aleodon'' are recognized: ''A. brachyramphus'' which was discovered in Tanzania, and ''A. cromptoni'' which was discovered most recently in Brazil. The name for the genus ''Aleodon'' was created when Alfred W. "Fuzz" Crompton initially discovered the type species, ''Aleodon brachyramphus''. The genus name, "Aleodon" referred to the grinding nature of the postcanine teeth, while "brachyramphus" referred to the relatively short snout of the specimen. The most recently discovered species, ''A. cromptoni'' was named after Crompton. Discovery and Classification In 1955, ''Aleodon'' was initially classified as a gomphodont cynodont based on the partial skull and lower jaw fossils found in 1933 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protheriodon
''Protheriodon'' is an extinct genus of probainognathian cynodonts which existed in the Santa Maria Formation of the Paraná Basin in southeastern Brazil during the middle Triassic period. It contains the species ''Protheriodon estudianti''. It was first described by Argentine palaeontologist José Bonaparte, who assigned it to the family Brasilodontidae ''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 foun .... More recent studies have however recovered it in a more basal position than other brasilodontids, just outside Prozostrodontia. Cladogram from Martinelli ''et al.'', 2017: References Prehistoric cynodont genera Ladinian genera Middle Triassic synapsids of South America Triassic Brazil Fossils of Brazil Santa Maria Formation Fossil taxa described in 2006 Tax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probainognathidae
Probainognathidae is an extinct family of insectivorous cynodonts which lived in what is now South America during the Middle to Late Triassic. The family was established by Alfred Romer in 1973 and includes two genera, ''Probainognathus'' from the Chañares Formation of Argentina and ''Bonacynodon'' from the ''Dinodontosaurus'' Assemblage Zone of Brazil. Probainognathids were closely related to the clade Prozostrodontia, which includes mammals and their close relatives. Description Members of Probainognathidae were relatively small-bodied animals, with skull lengths of around . The temporal region (area behind the eye sockets) was rather wide, and longer than the snout. The secondary palate was well-developed compared to earlier cynodonts, and the portion made up by the maxilla was larger than the part made from the palatine bone. The dentary, the tooth-bearing bone of the lower jaw, was quite tall when seen from the side. The mandibular symphysis (the joint between the two h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norian
The Norian is a division of the Triassic Period. It has the rank of an age ( geochronology) or stage (chronostratigraphy). It lasted from ~227 to million years ago. It was preceded by the Carnian and succeeded by the Rhaetian. Stratigraphic definitions The Norian was named after the Noric Alps in Austria. The stage was introduced into scientific literature by Austrian geologist Edmund Mojsisovics von Mojsvar in 1869. The Norian Stage begins at the base of the ammonite biozones of '' Klamathites macrolobatus'' and '' Stikinoceras kerri'', and at the base of the conodont biozones of '' Metapolygnathus communisti'' and '' Metapolygnathus primitius''. A global reference profile for the base (a GSSP) had in 2009 not yet been appointed. The top of the Norian (the base of the Rhaetian) is at the first appearance of ammonite species '' Cochloceras amoenum''. The base of the Rheatian is also close to the first appearance of conodont species '' Misikella spp.'' and '' Epigondolell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecteninion
''Ecteninion'' is an extinct genus of meat-eating cynodonts that lived during the Late Triassic ( Carnian) in South America. The type species ''Ecteninion lunensis'' was named by R.N. Martinez, C.L. May, and C.A. Forster in 1996. ''E. lunensis'' is known from a nearly complete skull of about in length. It was found in the Cancha de Bochas Member of the Ischigualasto Formation in the Ischigualasto-Villa Unión Basin in northwestern Argentina. at Fossilworks.org It has been interpreted as a basal . The |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madagascar Probainognathian
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa across the Mozambique Channel. At Madagascar is the world's second-largest island country, after Indonesia. The nation is home to around 30 million inhabitants and consists of the island of Madagascar (the fourth-largest island in the world), along with numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from the Indian subcontinent around 90 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90% of its wildlife is endemic. Human settlement of Madagascar occurred during or before the mid first millennium AD by Austronesian peoples, presumably arriving on outrigger canoes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals
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, tog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammaliaformes
Mammaliaformes ("mammalian forms") is a clade that contains the crown group mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts. It is defined as the clade originating from the most recent common ancestor of Morganucodonta and the crown group mammals; the latter is the clade originating with the most recent common ancestor of extant Monotremata, Marsupialia, and Placentalia. Besides Morganucodonta and the crown group mammals, Mammaliaformes includes Docodonta and ''Hadrocodium'' as well as the Triassic ''Tikitherium'', the earliest known member of the group. Mammaliaformes is a term of phylogenetic nomenclature. In contrast, the assignment of organisms to Mammalia has traditionally been founded on traits and, on this basis, Mammalia is slightly more inclusive than Mammaliaformes. In particular, trait-based taxonomy generally includes ''Adelobasileus'' and ''Sinoconodon'' in Mammalia, though they fall outside the Mammaliaformes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenocretosuchus
''Xenocretosuchus'' is an extinct genus of tritylodont therapsids from the Aptian (Early Cretaceous) Ilek Formation of Siberia, in the Russian Federation. The type species, ''X. sibiricus'', is known only from dental elements, as is ''X. kolossovi'', described from the Batylykh Formation in 2008.Lopatin & Agadjanian, 2008. "A Tritylodont (Tritylodontidae, Synapsida) from the Mesozoic of Yakutia." Retrieved fro/ref> Some authors have treated these species as part of the genus ''Stereognathus,'' otherwise known from the Middle Jurassic of Britain But this is rejected by other authors. Alongside ''Montirictus'' and '' Fossiomanus'', it is amongst the latest known non-mammaliform-synapsid Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptil ..., extending their range to the Early Cretaceous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montirictus
''Montirictus'' is an extinct genus of tritylodonts known from the Early Cretaceous Kuwajima Formation of Japan. It is currently the latest surviving tritylodontid species, and is closely related to the earlier '' Xenocretosuchus'' from mainland Asia, and the Jurassic ''Stereognathus ''Stereognathus'' is an extinct genus of tritylodontid cynodonts from the Middle Jurassic of the United Kingdom. There is a single named species: ''S. ooliticus'', named after the Great Oolite deposits of England. A second species, ''S. hebrid ...'' from the UK. It may be a species of the genus ''Stereognathus'', but resolution of its affinities conditions upon the discovery of additional material. References Prehistoric cynodont genera Fossil taxa described in 2016 Extinct animals of Japan Early Cretaceous synapsids Tritylodontids Fossils of Japan {{paleo-Therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', " chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
