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Xenachoffatia
''Xenachoffatia'' is a small Jurassic mammal from Portugal. It was a relatively early member of the also extinct order of Multituberculata. It lived during "the age of the dinosaurs" and belongs to the suborder Plagiaulacida, family Paulchoffatiidae. The genus ''Xenachoffatia'' ("for Xena Choffat") was named by Hahn G. and Hahn R. in 1998. The primary species ''Xenachoffatia oinopion'' (Hahn & Hahn, 1998) was found in Kimmeridgian (Upper Jurassic) Camadas de Guimarota of Guimarota, Portugal. The classification is based on three upper molars The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to .... References * Hahn & Hahn (1998), "Neue Beobachtungen an Plagiaulacoidea (Multituberculata) des Ober-Juras. 3. Der Bau der Molaren bei den Paulchoffatiidae." ''(New observations on the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paulchoffatiidae
Paulchoffatiidae is a family of extinct mammals that lived predominantly during the Upper Jurassic period, though a couple of genera are known from the Early Cretaceous. Fossils have been reported from Europe (Portugal, Spain, Germany and England) . Paulchoffatiids were members of the order Multituberculata. They were relatively early representatives and are within the informal suborder of "Plagiaulacida". The family was named by G. Hahn in 1969, and it honors the Portuguese geologist Léon Paul Choffat. Two subfamilies are recognized. The most productive fossil site for Paulchoffatiids has been Guimarota, Portugal. Remains from this locality are generally diagnosed on the basis of lower or upper jaws. In only one instance, that of ''Kuehneodon'', has it been possible to match the two up. Some of the lower jaws probably represent the same animals as some of the upper, so the diversity of Paulchoffatiids is very possibly exaggerated. As the site is now a flooded, disused coalmine ... [...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] |
Plagiaulacida
Plagiaulacida is a group of extinct multituberculate mammals. Multituberculates were among the most common mammals of the Mesozoic, "the age of the dinosaurs". Plagiaulacids are a paraphyletic grouping, containing all multituberculates that lie outside of the advanced group Cimolodonta. They ranged from the Middle Jurassic Period to the early Late Cretaceous of the northern hemisphere. During the Cenomanian, they were replaced by the more advanced cimolodontans. Kielan-Jaworowska and Hurum (2001) divides “Plagiaulacida” into three informal lineages, the paulchoffatiids, the plagiaulicids, and the allodontids. Allodontid line The Allodontid line may be a superfamily, Allodontoidea. Both allodontids and paulchoffatiids (below) were among the most basal of the plagiaulacids. The Allodontid line contains: The family Allodontidae is known from two genera from the Upper Jurassic Morrison Formation of North America. The family Zofiabaataridae contains a single genus, '' ... [...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 clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1998 In Paleontology
Flora Lycophytes Lycophyte research * Wehr (1998) reports, without description, ''Selaginella'' species spikemoss fossils occurring in the Eocene Okanagan highlands Klondike Mountain Formation. Fungi Fungal research *Currah, Stockey, & LePage (1998) describe the a phyllachoralean "tar spot" parasitizing ''Uhlia'' palm leaves, and host for a hyperparasitic pleosporalean fungus. They note them to be one of the first occurrences of hyperparasitic relationships in the fossil record. Arthropods Insects Molluscs Bivalves Amphibians newly named anurans Archosauromorpha Dinosaurs * A paper in the journal ''Nature'' is published by Karen Chin and others announcing the earlier discovery of a "king-sized coprolite" attributed to ''Tyrannosaurus rex''. * ''Lourinhasaurus'' gastroliths documented.Dantas et al. (1998). Sanders, Manley, and Carpenter (2001), "Table 12.1" page 167. * ''Cedarosaurus'' gastroliths documented.Sanders and Carpenter (1998). Sanders, Manley, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class (biology), class Mammalia (), characterized by the presence of mammary glands which in Female#Mammalian female, females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three ossicles, middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they Genetic divergence, diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant taxon, extant species of mammals have been described divided into 29 Order (biology), orders. The largest Order (biology), orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, Mole (animal), moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla (cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, pinniped, seals, and others). In terms of cladistic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portugal
Portugal, officially the Portuguese Republic, In recognized minority languages of Portugal: :* mwl, República Pertuesa is a country located on the Iberian Peninsula, in Southwestern Europe, and whose territory also includes the Macaronesian archipelagos of the Azores and Madeira. It features the westernmost point in continental Europe, its mainland west and south border with the North Atlantic Ocean and in the north and east, the Portugal-Spain border, constitutes the longest uninterrupted border-line in the European Union. Its archipelagos form two autonomous regions with their own regional governments. On the mainland, Alentejo region occupies the biggest area but is one of the least densely populated regions of Europe. Lisbon is the capital and largest city by population, being also the main spot for tourists alongside Porto, the Algarve and Madeira. One of the oldest countries in Europe, its territory has been continuously settled and fought over since prehistoric tim ... [...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, dod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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