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Cladotheria
Cladotheria is a clade (sometimes ranked as a legion) of mammals. It contains modern therian mammals (marsupials and placentals) and several extinct groups, such as the dryolestoids, amphitheriids and peramurids. The clade was named in 1975 by Malcolm McKenna. In 2002, it was defined as a node-based taxon containing "the common ancestor of dryolestids and living therians, plus all its descendants". A different, stem-based definition was given in 2013, in which Cladotheria contains all taxa that are closer to '' Mus musculus'' (the house mouse) than to the "symmetrodont" ''Spalacotherium tricuspidens''. Description Early cladotherians can be distinguished from other mammals by a number of derived traits ( apomorphies). Their teeth differed from those of the "symmetrodonts" by the evolution of a talonid shelf (hypoflexid) on the lower molars, which occluded with the paracone of the corresponding upper molars. A true talonid basin, allowing for the crushing and grin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Donodontidae
Cladotheria is a clade (sometimes ranked as a legion) of mammals. It contains modern therian mammals (marsupials and placentals) and several extinct groups, such as the dryolestoids, amphitheriids and peramurids. The clade was named in 1975 by Malcolm McKenna. In 2002, it was defined as a node-based taxon containing "the common ancestor of dryolestids and living therians, plus all its descendants". A different, stem-based definition was given in 2013, in which Cladotheria contains all taxa that are closer to ''Mus musculus'' (the house mouse) than to the " symmetrodont" ''Spalacotherium tricuspidens''. Description Early cladotherians can be distinguished from other mammals by a number of derived traits (apomorphies). Their teeth differed from those of the " symmetrodonts" by the evolution of a talonid shelf ( hypoflexid) on the lower molars, which occluded with the paracone of the corresponding upper molars. A true talonid basin, allowing for the crushing and grinding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dryolestida
Dryolestida is an extinct order of mammals, primarily and possibly exclusively known from the Jurassic and Cretaceous. They are considered members of the clade Cladotheria, close to the ancestry of therian mammals. It is also believed that they developed a fully mammalian jaw and also had the three middle ear bones. Most members of the group, as with most Mesozoic mammals, are only known from fragmentary tooth and jaw remains. The taxonomic composition of the group is contested. Aside from the uncontroversial Dryolestidae and the possibly paraphyletic Paurodontidae, which were small insectivores, known from the Middle Jurassic to Early Cretaceous of Laurasia, the Meridiolestida, a diverse group of mammals including both small insectivores and mid-large sized herbivores known from the Late Cretaceous to Miocene of South America and possibly Antarctica, are also often included. However, in many phylogenetic analyses, Meridiolestida are recovered as an unrelated group of cladot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meridiolestida
Meridiolestida is an extinct clade of mammals known from the Cretaceous and Cenozoic of South America and possibly Antarctica. They represented the dominant group of mammals in South America during the Late Cretaceous. Meridiolestidans were morphologically diverse, containing both small insectivores such as the "sabretooth-squirrel" '' Cronopio,supplementary information '' as well as the clade Mesungulatoidea/Mesungulatomorpha, which ranged in size from the shrew-sized '' Reigitherium'' to the dog-sized '' Peligrotherium.'' Mesungulatoideans had high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dryolestoid
Dryolestida is an extinct order of mammals, primarily and possibly exclusively known from the Jurassic and Cretaceous. They are considered members of the clade Cladotheria, close to the ancestry of therian mammals. It is also believed that they developed a fully mammalian jaw and also had the three middle ear bones. Most members of the group, as with most Mesozoic mammals, are only known from fragmentary tooth and jaw remains. The taxonomic composition of the group is contested. Aside from the uncontroversial Dryolestidae and the possibly paraphyletic Paurodontidae, which were small insectivores, known from the Middle Jurassic to Early Cretaceous of Laurasia, the Meridiolestida, a diverse group of mammals including both small insectivores and mid-large sized herbivores known from the Late Cretaceous to Miocene of South America and possibly Antarctica, are also often included. However, in many phylogenetic analyses, Meridiolestida are recovered as an unrelated group of cladot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dryolestidae
Dryolestidae is an extinct family of Mesozoic mammals, known from the Middle Jurassic to the Early Cretaceous of the North Hemisphere. The oldest known member, '' Anthracolestes'', is known from the Middle Jurassic Itat Formation of Western Siberia, but most other representatives are known from the Late Jurassic of North America and the Late Jurassic and Early Cretaceous of Europe. Most members are only known from isolated teeth and jaw fragments. Like many other groups of early mammals, they are though to have been insectivores. They are generally classified in Cladotheria, meaning that they are considered to be more closely related to marsupials and placentals than to monotremes. They are placed as part of the broader Dryolestida, which also includes the (possibly paraphyletic) Paurodontidae, and also sometimes the South American-Antarctic Meridiolestida, which are often considered unrelated cladotherians. Dyolestidae is not based on a phylogenetic definition, but instead on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphitheriid
Amphitheriidae is a family of Mesozoic mammals restricted to the Middle Jurassic of Britain, with indeterminate members also possibly known from the equivalently aged Itat Formation in Siberia and the Anoual Formation of Morocco. They were members of Cladotheria, more derived than members of Dryolestida, and forming a close relationship with Peramuridae.Panciroli E; Roger B.J. Benson; Richard J. Butler (2018).New partial dentaries of amphitheriid mammalian Palaeoxonodon ooliticus from Scotland, and posterior dentary morphology in early cladotherians. Acta Palaeontologica Polonica. in press. doi:10.4202/app.00434.2017. Amphitheriidae is the only family of the order Amphitheriida. Classification * Mammalia ** Yinotheria (monotremes and relatives) ** Theriimorpha ***†Eutriconodonta *** Theriiformes ****†Allotheria *****†Gondwanatheria *****†Multituberculata **** Trechnotheria ***** † Spalacotheriidae ***** † Zhangheotheriidae ***** Cladotheria ****** †Meridiolesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphitheriidae
Amphitheriidae is a family of Mesozoic mammals restricted to the Middle Jurassic of Britain, with indeterminate members also possibly known from the equivalently aged Itat Formation in Siberia and the Anoual Formation of Morocco. They were members of Cladotheria, more derived than members of Dryolestida, and forming a close relationship with Peramuridae.Panciroli E; Roger B.J. Benson; Richard J. Butler (2018).New partial dentaries of amphitheriid mammalian Palaeoxonodon ooliticus from Scotland, and posterior dentary morphology in early cladotherians. Acta Palaeontologica Polonica. in press. doi:10.4202/app.00434.2017. Amphitheriidae is the only family of the order Amphitheriida. Classification * Mammalia ** Yinotheria (monotremes and relatives) ** Theriimorpha ***† Eutriconodonta *** Theriiformes ****† Allotheria *****†Gondwanatheria *****† Multituberculata **** Trechnotheria ***** †Spalacotheriidae ***** † Zhangheotheriidae ***** Cladotheria ****** †Meri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henkelotherium Guimarotae
''Henkelotherium'' is an extinct genus of dryolestidan mammal from the Late Jurassic (Kimmeridgian) Camadas de Guimarota, in Portugal. Unlike many other Jurassic mammals, it is known from a largely complete skeleton, and is thought to have had an arboreal lifestyle. Description The skull of ''Henkelotherium'' is long, and presacral body length is . This suggest a weight of about . Paleobiology Primitive characters of ''Henkelotherium'' (e.g. asymmetric condyles of the femur) indicate that this species had a mode of locomotion similar to tree shrews and opossums. The small size of ''Henkelotherium'' and elongated tail made it suited to an arboreal lifestyle and capable of climbing trees, a notion supported by the paleoecological reconstruction of the Guimarota ecosystem indicating a densely vegetated environment. Taxonomy In cladistic analyses, ''Henkelotherium'' has been considered closely related to Dryolestidae, either as a part of that group, or as closely related ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paurodontidae
Paurodontidae is a family of Late Jurassic to Early Cretaceous mammals in the order Dryolestida. Remains of paurodontids have been found in the United States, Britain, Portugal, and Tanzania. The group likely represents a paraphyletic group of basal non dryolestid dryolestidans. '' Paurodon'' has been suggested to have been a specilast feeder on earthworms due to the morphology of its teeth closely resembling that of the golden mole genus ''Amblysomus ''Amblysomus'' (also narrow-headed golden mole or South African golden mole) is a genus of the golden mole family, Chrysochloridae, comprising five species of the small, insect-eating, burrowing mammals endemic to Southern Africa. All five spec ...''.A.O. Averianov and T. Martin (2015). "Ontogeny and taxonomy of Paurodon valens (Mammalia, Cladotheria) from the Upper Jurassic Morrison Formation of USA" (PDF). Proceedings of the Zoological Institute of the Russian Academy of Sciences 319 (3): 326–340. References Dryolestida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peramurid
The family Peramuridae is a family of mammals that lived in the Late Jurassic and Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro .... They are considered to be advanced cladotherians closely related to therian mammals as part of Zatheria. References * Cladotheria Jurassic mammals Prehistoric mammal families Tithonian first appearances Berriasian extinctions {{cretaceous-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peramuridae
The family Peramuridae is a family of mammals that lived in the Late Jurassic and Early Cretaceous. They are considered to be advanced cladotherians closely related to therian mammals as part of Zatheria Cladotheria is a clade (sometimes ranked as a legion) of mammals. It contains modern therian mammals (marsupials and placentals) and several extinct groups, such as the dryolestoids, amphitheriids and peramurids. The clade was named in 1975 .... References * Cladotheria Jurassic mammals Prehistoric mammal families Tithonian first appearances Berriasian extinctions {{cretaceous-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theria
Theria (; Greek: , wild beast) is a subclass of mammals amongst the Theriiformes. Theria includes the eutherians (including the placental mammals) and the metatherians (including the marsupials) but excludes the egg-laying monotremes. Characteristics Therian mammals give birth (''see viviparity'') to live young without a shelled egg. This is possible thanks to key proteins called syncytins which allow exchanges between the mother and its offspring through a placenta, even rudimental ones such as in marsupials. Genetic studies have suggested a viral origin of syncytins through the endogenization process. The marsupials and the placental mammals evolved from a common therian ancestor that gave live birth by suppressing the mother's immune system. While the marsupials continued to give birth to an underdeveloped fetus after a short pregnancy, the ancestors of placental mammals gradually evolved a prolonged pregnancy. Therian mammals no longer have the coracoid bone, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
