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Patagonia (mammal)
''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 severa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first epoch (geology), 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 followed the Oligocene and preceded 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 distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and Ape, hominoids into Eurasia. During the late Miocene, the conn ... [...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 seco ... [...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 — placentals and marsupials — and Monotremata,Agustí-Antón 2002, pp 3-4 but usually as closer to Theria than to monotremes. They are considered to be closely rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuco-tuco
A tuco-tuco is a neotropical rodent in the family Ctenomyidae. 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."Southern Tuco-tuco (''Ctenomys australis'')" ARKive. 4 October 2013. The relationships among the species are debated by s. 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. Their closest relatives are [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbivore
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat non-vascular autotrophs such as mosses, algae and lichens, but do not include those feeding on decomposed plant matters (i.e. detritivores) or macrofungi (i.e. fungivores). As a result of their plant-based diet, herbivorous animals typically have mouth structures ( jaws or mouthparts) well adapted to mechanically break down plant materials, and their digestive systems have special enzymes (e.g. amylase and cellulase) to digest polysaccharides. Grazing herbivores such as horses and cattles have wide flat- crowned teeth that are better adapted for grinding grass, tree bark and other tougher lignin-containing materials, and many of them evolved rumination or cecotropic behaviors to better extract nutrients from plants. A larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossorial
A fossorial animal () is one that is adapted to digging and which lives primarily (but not solely) underground. Examples of fossorial vertebrates are Mole (animal), moles, badgers, naked mole-rats, meerkats, armadillos, wombats, and mole salamanders. Among invertebrates, many molluscs (e.g., clams), insects (e.g., beetles, wasps, bees), and arachnids (e.g. spiders) are fossorial. Prehistoric evidence The physical adaptation of fossoriality is widely accepted as being widespread among many Prehistory, prehistoric Phylum, phyla and Taxon, taxa, such as bacteria and early eukaryotes. Furthermore, fossoriality has evolved independently multiple times, even within a single Family (biology), 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 lineag ... [...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 clade of mammals known from the Mesozoic and early Cenozoic. Shared characteristics of the group are the presence of lower molariform teeth equipped with longitudinal rows of cusps and enlarged incisors. Typically, the canine teeth are also lost. Allotheria includes Multituberculata, Gondwanatheria (which may be part of Multituberculata, as the sister group to Cimolodonta), and probably Haramiyida, (sometimes only including Euharamiyida) although some studies have recovered haramiyidans to be basal mammaliaforms unrelated to multituberculates. Allotherians are often placed as crown group mammals, more closely related to living marsupials and placentals (Theria) than to monotremes or eutriconodonts Eutriconodonta is an order of early mammals. Eutriconodonts existed in Asia (including pre-contact India), Africa, Europe, North and South America during the Jurassic and the Cretaceou ... [...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'' is an early gondwanatherian 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 Maastrichtian Maevarano Formation. ''Vintan ...'' is one of the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allothere
Allotheria (meaning "other beasts", from the Greek , '–other and , '–wild animal) is an extinct clade of mammals known from the Mesozoic and early Cenozoic. Shared characteristics of the group are the presence of lower molariform teeth equipped with longitudinal rows of cusps and enlarged incisors. Typically, the canine teeth are also lost. Allotheria includes Multituberculata, Gondwanatheria (which may be part of Multituberculata, as the sister group to Cimolodonta), and probably Haramiyida, (sometimes only including Euharamiyida) although some studies have recovered haramiyidans to be basal mammaliaforms unrelated to multituberculates. Allotherians are often placed as crown group mammals, more closely related to living marsupials and placentals (Theria) than to monotremes or eutriconodonts Eutriconodonta is an order of early mammals. Eutriconodonts existed in Asia (including pre-contact India), Africa, Europe, North and South America during the Jurassic and the Cretaceou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for 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/ricochetal (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 Mouse, mice, rats, squirrels, prairie dogs, porcupines, beavers, Cavia, guinea pigs, and hamsters. Once included wi ... [...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. (E ... [...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). However, other studies have shown that shrew opossums branched off first, and thus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
