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Patagoniidae
''Patagonia'' is an extinct genus of non-placental mammal from the Miocene of Argentina. Traditionally considered a metatherian ''incertae sedis'', one analysis suggested it to be a gondwanathere. However, this has been rejected by other authors. Description Currently, a single species is known, ''Patagonia peregrina'', hailing from the Colhuehuapian-dating deposits of the Sarmiento Formation, Chubut Province. The holotype, MACN-CH-869, is composed of a semi-complete mandible; isolated upper and lower teeth are also known. The jaw is short and deep, bearing an unfused subvertical dentary symphysis and dorsally positioned masseteric fossa. The incisors are rootless and extend lingually along the ventral border of the dentary up to the level of molariform 3, and the molariforms are hypsodont. The dental formula is: and the molariform elements are identical, so distinction between molars and premolars is impossible. Previously, the animal was thought to have canines, but sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premolars
The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered transitional teeth during chewing, or mastication. They have properties of both the canines, that lie anterior and molars that lie posterior, and so food can be transferred from the canines to the premolars and finally to the molars for grinding, instead of directly from the canines to the molars. Human anatomy The premolars in humans are the maxillary first premolar, maxillary second premolar, mandibular first premolar, and the mandibular second premolar. Premolar teeth by definition are permanent teeth distal to the canines, preceded by deciduous molars. Morphology There is always one large buccal cusp, especially so in the mandibular first premolar. The lower second p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multituberculates
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] |
Tuco-tuco
A tuco-tuco is a neotropical rodent in the family Ctenomyidae.Parada, A., G. D’Elia, C.J. Bidau, and E.P. Lessa. 2011. Species Groups and the Evolutionary Diversification of Tuco-Tucos, genus ''Ctenomys'' (Rodentia: Ctenomyidae). ''Journal of Mammalogy'' 92(3): 671-682. Tuco-tucos belong to the only living genus of the family Ctenomyidae, ''Ctenomys'', but they include approximately 60 different species. The common name, "tuco-tuco" comes from the "tuc-tuc" sound they make while they dig their burrows.Anonymous. 2013. "Southern Tuco-tuco (''Ctenomys australis'')." ARKive. 04 Oct. 2013. http://www.arkive.org/southern-tuco-tuco/ctenomys-australis/ The relationships among the species are debated by taxonomists. It has been described that they are in a state of "taxonomic chaos", but banded karyotypes have been used to help make progress on their taxonomic study.Lessa, E. 1998. The Molecular Phylogenetics of Tuco-Tucos (genus ''Ctenomys'', Rodentia: Octodontidae) Suggests an Early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthparts adapted to rasping or grinding. Horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, and other tough plant material. A large percentage of herbivores have mutualistic gut flora that help them digest plant matter, which is more difficult to digest than animal prey. This flora is made up of cellulose-digesting protozoans or bacteria. Etymology Herbivore is the anglicized form of a modern Latin coinage, ''herbivora'', cited in Charles Lyell's 1830 ''Principles of Geology''.J.A. Simpson and E.S.C. Weiner, eds. (2000) ''The Oxford English Dictionary'', vol. 8, p. 155. Richard Owen employed the anglicized term in an 1854 work on fossil teeth and skeletons. ''Herbivora'' is derived from Latin ''herba' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossorial
A fossorial () animal is one adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, naked mole-rats, clams, meerkats, and mole salamanders, as well as many beetles, wasps, and bees. Prehistoric evidence The physical adaptation of fossoriality is widely accepted as being widespread among many prehistoric phyla and taxa, such as bacteria and early eukaryotes. Furthermore, fossoriality has evolved independently multiple times, even within a single family. Fossorial animals appeared simultaneously with the colonization of land by arthropods in the late Ordovician period (over 440 million years ago). Other notable early burrowers include ''Eocaecilia'' and possibly ''Dinilysia''. The oldest example of burrowing in synapsids, the lineage which includes modern mammals and their ancestors, is a cynodont, ''Thrinaxodon liorhinus'', found in the Karoo of South Africa, estimated to be 251 million years old. Evidence shows that this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allotheria Cladogram Per Chimento 2015
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sudamericid
Sudamericidae is a family of gondwanathere mammals that lived during the late Cretaceous to Miocene. Its members include ''Lavanify'' and ''Vintana'' from the Cretaceous of Madagascar, ''Bharattherium'' (=''Dakshina'') from the Cretaceous of India, '' Gondwanatherium'' from the Cretaceous of Argentina, ''Sudamerica'' from the Paleocene of Argentina, and unnamed forms from the Eocene of Antarctica (closely related to ''Sudamerica'') and Cretaceous of Tanzania.Gurovich and Beck, 2009; Krause et al., 1997; Prasad, 2008; Prasad et al., 2007; Wilson et al., 2007 More recently, ''Patagonia'', a mammal from the Colhuehuapian stage of the Miocene of southern South America, has been suggested to be a sudamericid. ''Vintana ''Vintana sertichi'' (from Malagasy vintana, "luck" ) is an early groundhog-like mammal dating from the Late Cretaceous, approximately 66 million years ago. Scientists found the lone fossil, a skull, on Madagascar's west coast in the Maastrichti ...'' is one of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allothere
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, whose i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groeberiid
Groeberiidae is a family of strange non- placental mammals from the Eocene and Oligocene epochs of Patagonia, Argentina and Chile, South America. Originally classified as paucituberculate marsupials, they were suggested to be late representatives of the allothere clade Gondwanatheria. However, the relationship of the type genus, '' Groeberia'', to Gondwanatheria has been firmly rejected by other scholars. History The type species, '' Groeberia minoprioi'', was first described by Bryan Patterson in 1952. This type specimen, MMP 738, is composed of a mandibular symphisis, incisors and four broken molars. A second species within the genus, '' Groeberia pattersoni'', was described by G. G. Simpson in 1970, and is known from at least two specimens.Goin, F.J., Abello M.A. & Chornogubsky L. 2010Middle Tertiary marsupials from Central Patagonia (Early Oligocene of Gran Barranca): Understanding South America’s ''Grande Coupure'' En: Madden R.H., Carlini A.A., Vucetich M.G. & Kay R.F. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paucituberculata
Paucituberculata is an order of South American marsupials. Although currently represented only by the seven living species of shrew opossums, this order was formerly much more diverse, with more than 60 extinct species named from the fossil record, particularly from the late Oligocene to early Miocene epochs. The earliest paucituberculatans date to the late Paleocene (Itaboraian South American land mammal age). The group went through a pronounced decline in the middle Miocene epoch, which resulted in the extinction of all families of this order except for the living shrew opossums (Caenolestidae). Extinct families of Paucituberculatans include Pichipilidae, Palaeothentidae, and Abderitidae. Classification It is one of two clades of Ameridelphia, a paraphyletic group; genetic studies have shown these animals to be a sister group to Australidelphia (i.e., Didelphimorphia branched off first). The Paucituberculata were once considered to be closely related to South American p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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