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Ptilodontidae
Ptilodontidae is a family of primitive mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and Paleocene of North America. The Ptilodontidae family was originally named Ptilodontinae and classified as a subfamily by Edward Drinker Cope in 1887. It was amended by Gregory and Simpson in 1926 to its current status. In addition, Cope mistakenly classified the ''Ptilodus'' genus as a marsupial. He originally named it ''Chirox'', and placed it in the new family Chirogidae in 1887. Since it has been reclassified, and Chirogidae is now officially a synonym of Ptilodontidae. One of the most outstanding features of this family of squirrel-like, arboreal mammals, was the peculiar shape of their last lower premolar 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 premo ... [...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 clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptilodontoids
Ptilodontoidea is a group of extinct mammals from the Northern Hemisphere. They were generally small, somewhat rodent-like creatures of the extinct order Multituberculata. Some of these genera boast a great many species, though remains are generally sparse. '' Ptilodus'' is among the best known, and there's a tendency to depict it as an analog of a squirrel. Upper Cretaceous remains are known from North America and Europe. Later representatives (Paleocene - Eocene) hail from North America, Europe and Asia. These were some of the last multituberculates, and they are within the suborder Cimolodonta. The superfamily is further divided into the following families: *Neoplagiaulacidae - 10 genera; * Ptilodontidae - 4 genera; *Cimolodontidae Cimolodontidae is a family of fossil mammals within the extinction, extinct Order (biology), order Multituberculata. Representatives are known from the Upper Cretaceous and Paleocene of North America. The family Cimolodontidae was name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prochetodon
''Prochetodon'' is a genus of mammals from the extinct order Multituberculata. It lived during the Upper Paleocene and the Lower Eocene in North America. The genus was formally named by G. L. Jepsen in 1940. ( Jepsen, 1940) ''P. cavus'' The species ''Prochetodon cavus'' weighed about 135 g. Remains have been discovered in Wyoming, in the United States. They were found in the Princeton Quarry, and the deposits were dated from the Upper Paleocene to the Lower Eocene. Material is in the collection of the Peabody Museum of Natural History at Yale. The species was named by G. L. Jepsen in 1940. ( Jepsen, 1940) ''P. foxi'' The species ''Prochetodon foxi'' weighed about 200 g. Remains have been discovered in Wyoming and Montana in the United States, in the Long Draw Quarry, and in the Swan Hills of Alberta, Canada. The strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes th ... [...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. fractu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subfamily
In biological classification, a subfamily ( Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoological names with "-inae". See also * International Code of Nomenclature for algae, fungi, and plants The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ... * International Code of Zoological Nomenclature * Rank (botany) * Rank (zoology) Sources {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene Extinctions
The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. In the Paleocene, the continents of the Northern Hemisphere were still connected via so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous First Appearances
Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, a concept in econometrics Music * ''Late'' (album), a 2000 album by The 77s * Late!, a pseudonym used by Dave Grohl on his '' Pocketwatch'' album * Late (rapper), an underground rapper from Wolverhampton * "Late" (song), a song by Blue Angel * "Late", a song by Kanye West from '' Late Registration'' Other * Late (Tonga), an uninhabited volcanic island southwest of Vavau in the kingdom of Tonga * "Late" (''The Handmaid's Tale''), a television episode * LaTe, Oy Laivateollisuus Ab, a defunct shipbuilding company * Late may refer to a person who is Dead See also * * * '' Lates'', a genus of fish in the lates perch family * Later (other) * Tardiness * Tardiness (scheduling) {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Naturalist
''The American Naturalist'' is the monthly peer-reviewed scientific journal of the American Society of Naturalists, whose purpose is "to advance and to diffuse knowledge of organic evolution and other broad biological principles so as to enhance the conceptual unification of the biological sciences." It was established in 1867 and is published by the University of Chicago Press. The journal covers research in ecology, evolutionary biology, population, and integrative biology. , the editor-in-chief is Daniel I. Bolnick. According to the ''Journal Citation Reports'', the journal had a 2020 impact factor of 3.926. History The journal was founded by Alpheus Hyatt, Edward S. Morse, Alpheus S. Packard Jr., and Frederick W. Putnam at the Essex Institute in Salem, Massachusetts Salem ( ) is a historic coastal city in Essex County, Massachusetts, located on the North Shore of Greater Boston. Continuous settlement by Europeans began in 1626 with English colonists. Salem would become ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occlusion (dentistry)
Occlusion, in a dental context, means simply the contact between teeth. More technically, it is the relationship between the maxillary (upper) and mandibular (lower) teeth when they approach each other, as occurs during chewing or at rest. Static occlusion refers to contact between teeth when the jaw is closed and stationary, while dynamic occlusion refers to occlusal contacts made when the jaw is moving. The masticatory system also involves the periodontium, the TMJ (and other skeletal components) and the neuromusculature, therefore the tooth contacts should not be looked at in isolation, but in relation to the overall masticatory system. Anatomy of Masticatory System One cannot fully understand occlusion without an in depth understanding of the anatomy including that of the teeth, TMJ, musculature surrounding this and the skeletal components. The Dentition and Surrounding Structures The human dentition consists of 32 permanent teeth and these are distributed betwee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premolar
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 sec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym (taxonomy)
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called ''Pinus abies''. This name is no longer in use, so it is now a synonym of the current scientific name, '' Picea abies''. * In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refers to a taxon at that rank - for example, the name ''Papilio prorsa'' Linnaeus, 1758 is a junior synonym of ''Papilio levana'' Linnaeus, 1758, being names for different seasonal forms of the species now referred to as ''Araschnia l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupial
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant species occur on the Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in Central America, and one species, the Virginia opossum, in Nort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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