|
Dryolestoid
Dryolestida is an extinct order of mammals, known from the Jurassic and Cretaceous. They are considered Basal (phylogenetics), basal members of the clade Cladotheria, close to the ancestry of therian mammals. It is also believed that they developed a fully mammalian jaw and also had the Ossicle, three middle ear bones. Most members of the group, as with most Mesozoic mammals, are only known from fragmentary tooth and jaw remains. The group contains Dryolestidae and the possibly Paraphyly, paraphyletic Paurodontidae, and some other unplaced genera, which were small insectivores, known from the Middle Jurassic to Early Cretaceous of Laurasia, primarily Europe and North America, with a single record from Asia. During the Late Jurassic in North America and from the Late Jurassic to Early Cretaceous in Europe, they were among the most diverse mammal groups. They have sometimes been placed as part of a broader group, the "Dryolestoidea", which typically includes Dryolestida and Meridio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladotheria
Cladotheria is a clade (sometimes ranked as a legion) of mammals. It contains modern therian mammals (marsupials and placentals) and several extinct groups, such as the "dryolestoids", amphitheriids and peramurids. The clade was named in 1975 by Malcolm McKenna. In 2002, it was defined as a node-based taxon containing "the common ancestor of dryolestids and living therians, plus all its descendants". A different, stem-based definition was given in 2013, in which Cladotheria contains all taxa that are closer to ''Mus musculus'' (the house mouse) than to the " symmetrodont" '' Spalacotherium tricuspidens''. Cladotheria incorporates a set of nested mammal clades culminating in Tribosphenida (also known as Boreosphenida), mammals with fully tribosphenic teeth such as therians and a few of their closest relatives. The clade Prototribosphenida includes "the common ancestor of '' Vincelestes'' and living therians, plus all of its descendants". Apart from tribosphenids, Prototrib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paurodon
''Paurodon'' is an extinct genus of Late Jurassic mammal from the Morrison Formation of the Western United States. Taxonomy ''Paurodon'' is the type genus of the dryolestidan group Paurodontidae. ''Araeodon'', ''Archaeotrigon'', ''Foxraptor'', and ''Pelicopsis'' are apparently growth stages of ''Paurodon''. Distribution and stratigraphy Remains of ''Paurodon'' have been found in stratigraphic zone 5 of the Morrison Formation in Como Bluff, Wyoming.Foster, J. (2007). "Appendix." ''Jurassic West: The Dinosaurs of the Morrison Formation and Their World''. Indiana University Press. pp. 327-329. Biology ''Paurodon'' was strongly convergent with modern golden moles in terms of dentition and jaw shape. This suggests that its diet was composed of earthworms (unlike other contemporary dryolestoids, which were more insectivorous)Ontogeny and taxonomy of Paurodon valens (Mammalia, Cladotheria) from the Upper Jurassic Morrison Formation of USA. (pdf), Proceedings of the Zoological Institute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high Sea level#Local and eustatic, eustatic sea levels that created numerous shallow Inland sea (geology), inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drescheratherium
''Drescheratherium'' is an extinct genus of mammal from the Late Jurassic (Kimmeridgian) Camadas de Guimarota of Leiria, Portugal. It is represented by fairly complete upper jaws with teeth. It bears elongated upper canines, though not to the extent another dryolestoid, '' Cronopio'', does. Supplementary information See also * Prehistoric mammal ** List of prehistoric mammals This is an incomplete list of prehistoric mammals. It does not include List of mammals, extant mammals or List of extinct mammals, recently extinct mammals. For extinct primate species, see: list of fossil primates.Mikko's Phylogeny Archiv Ma ... References Dryolestida Late Jurassic mammals of Europe Jurassic Portugal Fossils of Portugal Fossil taxa described in 1998 Prehistoric mammal genera {{jurassic-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meridiolestida
Meridiolestida is an extinct clade of mammals known from the Cretaceous and Cenozoic of South America and possibly Antarctica. They represented the dominant group of mammals in South America during the Late Cretaceous. Meridiolestidans were morphologically diverse, containing both small insectivores such as the "sabretooth-squirrel" ''Cronopio (mammal), Cronopio,supplementary information '' as well as the clade Mesungulatoidea/Mesungulatomorpha, which ranged in size from the shrew-sized ''Reigitherium'' to the dog-sized ''Peligrotherium.'' Mesungulatoideans had highly modified dentition with bunodont (low and rounded) teeth, and were likely herbivores/omnivores. Meridiolestidans are generally classified within Cladotheria, more c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathonian
In the geologic timescale the Bathonian is an age (geology), age and stage (stratigraphy), stage of the Middle Jurassic. It lasted from approximately 168.2 ±1.2 annum, Ma to around 165.3 ±1.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. Stratigraphic definitions The Bathonian Stage takes its name from Bath, Somerset, Bath, a spa town in England built on Jurassic limestone (the Latinized form of the town name is ''Bathonium''). The name was introduced in scientific literature by Belgian geologist Jean Baptiste Julien d'Omalius d'Halloy, d'Omalius d'Halloy in 1843. The original type locality (geology), type locality was located near Bath. The French palaeontologist Alcide d'Orbigny was in 1852 the first to define the exact length of the stage. The base of the Bathonian is at the first appearance of ammonite species ''Parkinsonia (ammonite), Parkinsonia (Gonolkites) convergens'' in the stratigraphic column. The global referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics, having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia (reptiles), which is paraphyletic with respect to birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantotheria
Pantotheria is an abandoned taxon of Mesozoic mammals. This group is now considered an informal "wastebasket" taxon and has been replaced by Dryolestida as well as other groups. It is sometimes treated as an infraclass and older books refer to it as being related to symmetrodonts. One classification makes it an infraclass with a single order, Eupantotheria. Taxonomy List of mammals that were at one time included in the group PantotheriaMikko's Phylogeny Archiv *Genus †'' Tribactonodon, Tribactonodon bonfieldi'' Sigogneau-Russell, Hooker & Ensom 2001 *Genus †'' Paraungulatum rectangularis'' Bonaparte 1999 *Genus †'' Argaliatherium robustum '' Cifelli & Davis 2015 *Genus †'' Carinalestes murensis'' Cifelli & Davis 2015 *Genus †'' Hypomylos'' Sigogneau-Russell 1992 *Family † Picopsidae Fox 1980 **Genus †'' Picopsis pattersoni'' Fox 1980 **Genus †'' Tirotherium aptum'' Montellano-Ballesteros & Fox 2015 *Family † Casamiqueliidae Bonaparte 1999 **Genus †'' Casam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
José Bonaparte
José Fernando Bonaparte (14 June 1928–18 February 2020) was an Argentine paleontologist who discovered a plethora of South American dinosaurs and mentored a new generation of Argentine paleontologists. He has been described by paleontologist Peter Dodson as "almost singlehandedly...responsible for Argentina becoming the sixth country in the world in kinds of dinosaurs." Biography Bonaparte was the son of an Italian sailor, with no close connection to Napoleon's House of Bonaparte. He was born in Rosario, Santa Fe, Argentina, and grew up in Mercedes, Buenos Aires. Despite a lack of formal training in paleontology, he started collecting fossils with many friends at an early age, and created a museum in their home town. He later became the curator of the National University of Tucumán, where he was named Doctor ''honoris causa'' in 1976, and then in the late 1970s became a senior scientist at the Museo Argentino de Ciencias Naturales in Buenos Aires. Bonaparte was a two-tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth
A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the outermost embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brandoniidae
Dryolestidae is an extinct family of Mesozoic mammals, known from the Middle Jurassic to the Early Cretaceous of the North Hemisphere. The oldest known member, '' Anthracolestes'', is known from the Middle Jurassic Itat Formation of Western Siberia, but most other representatives are known from the Late Jurassic of North America and the Late Jurassic and Early Cretaceous of Europe. Most members are only known from isolated teeth and jaw fragments. Like many other groups of early mammals, they are thought to have been insectivores. They are generally classified in Cladotheria, meaning that they are considered to be more closely related to marsupials and placentals than to monotremes. They are placed as part of the broader Dryolestida, which also includes the (possibly paraphyletic) Paurodontidae, and also sometimes the South American-Antarctic Meridiolestida, which are often considered unrelated cladotherians. Dryolestidae taxon is not based on a phylogenetic definition, but inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
