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Aegialodontia
Aegialodontia is a clade of extinct early mammals, close to the origin of Boreosphenida. The clade includes some of the oldest known tribosphenic taxa, until the discovery of ''Tribactonodon'' from the Berriasian Durlston Formation in 2001 in paleontology, 2001, ''Aegialodon'' from the Valanginian Wadhurst Clay Formation was the oldest taxon with the tooth form. The Aptian to Albian taxon ''Kielantherium'' from Mongolia, formerly a synonym of ''Aegialodon'', is also within the group, sister to ''Aegialodon'' within Aegialodontidae. References Prehistoric mammals Tribosphenida {{Cretaceous-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boreosphenida
Tribosphenida is a group (infralegion) of mammals that includes the ancestor of ''Hypomylos'', Aegialodontia and Theria (the last common ancestor of marsupials and placentals plus all of its descendants). Its current definition is more or less synonymous with Boreosphenida. Characteristics Tribosphenid mammals were originally grouped on the basis of triangular or V-shaped (Molar (tooth)#Tribosphenic, tribosphenic) molars. Since then, other unrelated mammal groups have been found to have tribosphenic molars, such as the australosphenidans (a group that includes the still extant monotremes), suggesting that as a synapomorphy this is fundamentally useless as it evolved multiple times among mammals. However, a clade between the aforementioned groups, the "true Tribosphenida" or Boreosphenida, is still identifiable, united by characteristics such as the lack of a mesial cingulid and of a triangulated trigonid on the last premolar. They are also united by postcranial features such as t ... [...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] |
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 Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegialodon
''Aegialodon dawsoni'' is an extinct mammal from the early Cretaceous, known from fossilised teeth discovered in the Wadhurst Clay Formation (dating to about 136 million years ago) near Cliff End, Hastings, East Sussex Hastings () is a large seaside town and Borough status in the United Kingdom, borough in East Sussex on the south coast of England, east to the county town of Lewes and south east of London. The town gives its name to the Battle of Hastings, .... References Early Cretaceous mammals of Europe Valanginian genera Prehistoric mammal genera Fossil taxa described in 1965 {{cretaceous-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berriasian
In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago). The Berriasian succeeds the Tithonian (part of the Jurassic) and precedes the Valanginian. Stratigraphic definition The Berriasian Stage was introduced in scientific literature by Henri Coquand in 1869. It is named after the village of Berrias in the Ardèche department of France. The largely non-marine English Purbeck Formation is in part of Berriasian age.In fact, the first rocks to be described of this age were the beds of the English Purbeck Formation, named as the Purbeckian by Alexandre Brongniart in 1829 following description by Henry De la Beche, William Buckland, Thomas Webster and William Henry Fitton. The base of the Berriasian, which is also the base of the Cretaceous System, has traditionally been placed at the first ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Durlston Formation
The Durlston Formation is a geologic formation in England. Particularly in the Isle of Purbeck. It preserves fossils dating back to the Berriasian stage of the Lower Cretaceous. Vertebrate paleobiota Crocodyliformes See also * List of fossiliferous stratigraphic units in England See also *Lists of fossiliferous stratigraphic units in Europe * Lists of fossiliferous stratigraphic units in the United Kingdom References * {{DEFAULTSORT:Fossiliferous stratigraphic units in England England England is a country ... References * Cretaceous England {{England-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2001 In Paleontology
Plants Pteridophyta Conifers Angiosperms Arthropods Insects Fishes Newly named bony fishes Amphibians Newly named amphibians Ichthyosaurs Turtles Newly named turtles Lepidosauromorphs Newly named basal lepidosauromorphs Newly named plesiosaurs Newly named sphenodonts Archosauromorphs Newly named basal archosauromorphs Newly named crurotarsans Newly named dinosaurs Data courtesy of George Olshevsky's dinosaur genera list. Newly named birds Newly named pterosaurs Synapsids Non-mammalian Mammalian Footnotes Complete author list As science becomes more collaborative, papers with large numbers of authors are becoming more common. To prevent the deformation of the tables, these footnotes list the contributors to papers that erect new genera and have many authors. References {{Reflist, 2 2000s in paleontology Paleontology Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valanginian
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceous and precedes the Hauterivian Stage of the Lower Cretaceous. Stratigraphic definitions The Valanginian was first described and named by Édouard Desor in 1853. It is named after Valangin Valangin () is a former municipality in the district of Val-de-Ruz in the canton of Neuchâtel in Switzerland. On 1 January 2021 the former municipalities of Corcelles-Cormondrèche, Peseux and Valangin merged into the municipality of Neuchâ ..., a small town north of Neuchâtel in the Jura Mountains of Switzerland. The base of the Valanginian is at the first appearance of Calpionellidae, calpionellid species ''Calpionellites darderi'' in the stratigraphic column. A global reference section (a GSSP) had in 2009 not yet been appointed. The top o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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