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Allotheria
Allotheria (meaning "other beasts", from the Greek , '–other and , '–wild animal) is an extinct branch of successful Mesozoic mammals. The most important characteristic was the presence of lower molariform teeth equipped with two longitudinal rows of cusps. Allotheria includes Multituberculata, Gondwanatheria (which may be part of Multituberculata, as the sister group to Cimolodonta), and probably Haramiyida, although some studies show them to be more basal mammaliaforms rather than true mammals, therefore differing from true allotheres significantly. Allotheres also had a narrow pelvis, indicating that they gave birth to tiny helpless young like marsupials or laid eggs and gave milk to feed their young like monotremes do. This is a feature of all non-placental mammals. Interpretations When he first identified Allotheria in 1880, Othniel Marsh regarded this group as an order within Marsupialia. However, in 1997 McKenna and Bell classified Allotheria as an infraclass I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allotheria
Allotheria (meaning "other beasts", from the Greek , '–other and , '–wild animal) is an extinct branch of successful Mesozoic mammals. The most important characteristic was the presence of lower molariform teeth equipped with two longitudinal rows of cusps. Allotheria includes Multituberculata, Gondwanatheria (which may be part of Multituberculata, as the sister group to Cimolodonta), and probably Haramiyida, although some studies show them to be more basal mammaliaforms rather than true mammals, therefore differing from true allotheres significantly. Allotheres also had a narrow pelvis, indicating that they gave birth to tiny helpless young like marsupials or laid eggs and gave milk to feed their young like monotremes do. This is a feature of all non-placental mammals. Interpretations When he first identified Allotheria in 1880, Othniel Marsh regarded this group as an order within Marsupialia. However, in 1997 McKenna and Bell classified Allotheria as an infraclass I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multituberculata
Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, and reached a peak diversity during the Late Cretaceous and Paleocene. They eventually declined from the mid Paleocene onwards, disappearing from the known fossil record in the late Eocene. They are the most diverse order of Mesozoic mammals with more than 200 species known, ranging from mouse-sized to beaver-sized. These species occupied a diversity of ecological niches, ranging from burrow-dwelling to squirrel-like arborealism to jerboa-like hoppers. Multituberculates are usually placed as crown mammals outside either of the two main groups of living mammals—Theria, including placentals and marsupials, and MonotremataAgustí-Antón 2002, pp 3-4—but usually as closer to Theria than to monotremes. They are considered to be clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cifelliodon
''Cifelliodon'' is an extinct genus of mammaliaforms from the Lower Cretaceous of North America. In the describing paper, it was considered one of the latest surviving haramiyids yet known, belonging to the family Hahnodontidae. Its discovery led to the proposal to remove hahnodontids from the larger well-known group, the multituberculates. However, later papers have considered it to be a basal allotherian outside of Haramiyida. The sole species in the genus, ''Cifelliodon wahkarmoosuch'', was found in the geological rock unit called the Yellow Cat Member, part of the Cedar Mountain Formation in Grand County, Utah. This rock unit dates to between 139-124 million years old. It was found alongside the remains of several dinosaurs - a large iguanodontian, a dromaeosaur, and an ornithopod - and parts of a crocodyliform. Etymology The genus name, ''Cifelliodon'', means Cifelli's tooth, and honours the well-known mammal palaeontologist, Richard Cifelli. The species name, ''C. wahkarm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwanatheria
Gondwanatheria is an extinct group of mammaliaforms that lived in parts of Gondwana, including Madagascar, India, South America, Africa and Antarctica during the Upper Cretaceous through the Paleogene (and possibly much earlier, if '' Allostaffia'' is a member of this group). Until recently, they were known only from isolated teeth, a few lower jaws, two partial skulls and one complete cranium. They are generally considered to be closely related to the multituberculates and likely the euharamiyidians, well known from the Northern Hemisphere, with which they form the clade Allotheria. Classification For several decades the affinities of the group were not clear, being first interpreted as early xenarthrans, or "toothless" mammals similar to the modern anteater. A variety of studies have placed them as allotheres related to multituberculates, possibly even true multituberculates, closer to cimolodonts than "plagiaulacidans" are. However, a more recent study recovered them as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haramiyida
Haramiyida ("thief" from Arabic الحرامية (al ḥarāmiyah), "thief, bandit") is a possibly polyphyletic order of mammaliaform cynodonts or mammals of controversial taxonomic affinites. Their teeth, which are by far the most common remains, resemble those of the multituberculates. However, based on ''Haramiyavia'', the jaw is less derived; and at the level of evolution of earlier basal mammals like ''Morganucodon'' and ''Kuehneotherium'', with a groove for ear ossicles on the dentary. If they are early multituberculates, they would be the longest lived mammalian clade of all time. However, a more recent study in November 2015 may dispute this and suggested the Haramiyida were not crown mammals, but were part of an earlier offshoot of mammaliaformes instead. It is also disputed whether the Late Triassic species are closely related to the Jurassic and Cretaceous members belonging to Euharamiyida/Eleutherodontida, as some phylogenetic studies recover the two groups as unrelate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megaconus
''Megaconus'' is an extinct genus of allotherian mammal from the Middle Jurassic Tiaojishan Formation of Inner Mongolia, China. The type and only species, ''Megaconus mammaliaformis'' was first described in the journal ''Nature'' in 2013. ''Megaconus'' is thought to have been a herbivore that lived on the ground, having a similar posture to modern-day armadillos and rock hyraxes. ''Megaconus'' was in its initial description found to be member of a group called Haramiyida. A phylogenetic analysis published along its description suggested that haramiyidans originated before the appearance of true mammals, but in contrast, the later description of the haramiyidan '' Arboroharamiya'' in the same issue of ''Nature'' indicated that haramyidans were true mammals. If haramiyidans are not mammals, ''Megaconus'' would be one of the most basal ("primitive") mammaliaforms to possess fur, and an indicator that fur evolved in the ancestors of mammals and not the mammals themselves. Howeve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptilodus
''Ptilodus'' (meaning "soft-haired") is a genus of mammals from the extinct order of Multituberculata, and lived during the Paleocene in North America. ''Ptilodus'' was a relatively large multituberculate of in length, which is about the same size as a squirrel. Its feet, legs and long tail suggest it was a good climber, so it very possibly led a squirrel-like lifestyle. The genus was named by paleontologist Edward Drinker Cope in 1881. Cope also mistakenly assigned some material belonging to this genus to ''Chirox'' in 1884. Elements from '' Ectypodus'' (Jepsen, 1940) and ''Neoplagiaulax'' have also been reassigned to this genus. Species There are seven species, and others have been proposed at one time or another. ''P. nellieae'' (Bell, 1941) is apparently mentioned in a manuscript, rather than a publication. ''P. sinclairi'' (Simpson, 1935) seems to have become ''Parectypodus sinclairi''. In botany, ''Ptilodus pyramidatus'' is an extinct Australian plant. ''P. fractus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
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 with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cimolodonta
Cimolodonta is a taxon of extinct mammals that lived from the Cretaceous to the Eocene. They were some of the more derived members of the extinct order Multituberculata. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents. The more basal multituberculates are found in a different suborder, "Plagiaulacida", a paraphyletic group containing all non cimolodontan multituberculates. Cimolodonta is apparently a natural (monophyletic) suborder. Remains have been identified from across the Northern Hemisphere. They first appeared during the Aptian, and completely replaced the more primitive plagiaulacidans by the early Late Cretaceous. The taxon is recognized as the informal Paracimexomys group and the superfamilies Djadochtatherioidea, Taeniolabidoidea, and Ptilodontoidea. Additionally, and of uncertain affinities, are the families Cimolomyidae, Boffiidae, Eucosmodontidae, Kogaionidae, Microcosmodontidae and the two genera ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Mammals
This is an incomplete list of prehistoric mammals. It does not include extant mammals or recently extinct mammals. For extinct primate species, see: list of fossil primates.Mikko's Phylogeny Archiv Mammaliaformes ' *Genus †''Adelobasileus'' Lucas & Hunt 1990 *Genus †'' Bocaconodon'' Montellano, Hopson & Clark 2008 *Genus †''Delsatia'' Sigogneau-Russell & Godefroit 1997 *Genus †''Tricuspes'' von Huene 1933 *Genus †'' Hadrocodium'' Luo, Crompton & Sun 2001 *Genus †'' Fruitafossor'' Luo & Wible 2005 Order † Dinnetheria *Family † Dinnetheriidae Averianov & Lopatin 2011 **Genus †''Dinnetherium'' Jenkins, Crompton & Downs 1983 Order † Siconodontiformes *Family † Siconodontidae Mills 1971 **Genus †''Sinoconodon'' Patterson & Olson 1961 Order † Morganucodonta ' *Genus †''Bridetherium'' Clemens 2011 *Genus †''Hallautherium'' Clemens 1980 *Genus †''Paceyodon'' Clemens 2011 *Genus †''Purbeckodon'' Butler et al. 2012 *Genus †''Rosierodon'' Debuyssche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal Taxonomy
Mammalia is a class of animal within the phylum Chordata. Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is universally accepted; McKenna & Bell (1997) and Wilson & Reader (2005) provide useful recent compendiums. Many earlier ideas from Linnaeus et al. have been completely abandoned by modern taxonomists, among these are the idea that bats are related to birds or that humans represent a group outside of other living things. Competing ideas about the relationships of mammal orders do persist and are currently in development. Most significantly in recent years, cladistic thinking has led to an effort to ensure that all taxonomic designations represent monophyletic groups. The field has also seen a recent surge in interest and modification due to the results of molecular phylogenetics. George Gaylord Simpson's classic "Principles of Classification and a Classification of Mammals" ( Simpson, 1945) t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammaliaform
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 Mammaliaform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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