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Carnassial Shear
Carnassials are paired upper and lower teeth modified in such a way as to allow enlarged and often self-sharpening edges to pass by each other in a shearing manner. This adaptation is found in carnivorans, where the carnassials are the modified fourth upper premolar and the first lower molar, however this may vary in family. These teeth are also referred to as sectorial teeth. Taxonomy The name carnivoran is applied to a member of the order Carnivora. Carnivorans possess a common arrangement of teeth called carnassials, in which the first lower molar and the last upper premolar possess blade-like enamel crowns that act similar to a pair of shears for cutting meat. This dental arrangement has been modified by adaptation over the past 60 million years for diets composed of meat, for crushing vegetation, or for the loss of the carnassial function altogether as in seals, sea lions, and walruses. Carnassial dentition Carnassial teeth are modified molars (and in the case of carnivo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctocyonidae
Arctocyonidae (from Greek ''arktos'' ''kyôn'', "bear/dog-like") has been defined as an extinct family of unspecialized, primitive mammals with more than 20 genera. Animals assigned to this family were most abundant during the Paleocene, but extant from the late Cretaceous to the early Eocene (). Like most early mammals, their actual relationships are very difficult to resolve. No Paleocene fossil has been unambiguously assigned to any living order of placental mammals, and many genera resemble each other: generalized robust, not very agile animals with long tails and all-purpose chewing teeth, living in warm closed-canopy forests with many niches left vacant by the K-T extinction. Arctocyonids were early defined as a family of creodonts (early predators), then reassigned to the condylarths (primitive plant-eaters, now understood as a wastebasket taxon). More recently, these animals have been thought to be the ancestors of the orders Mesonychia and Cetartiodactyla, although some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gobiconodon
''Gobiconodon'' is an extinct genus of carnivorous mammal from the Middle Jurassic to Early Cretaceous. It weighed , had a skull of in length, and had in presacral body length. It was one of the largest mammals known from the Mesozoic. Like other gobiconodontids, it possesses several speciations towards carnivory, such as shearing molar teeth, large canine-like incisors and powerful jaw and forelimb musculature, indicating that it probably fed on vertebrate prey; rather uniquely among predatory mammals and other eutriconodonts, the lower canines were vestigial, with the first lower incisor pair having become massive and canine-like. Like the larger ''Repenomamus'' there might be some evidence of scavenging Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding be ....Zofia Kielan-Jaworo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repenomamus
''Repenomamus'' (Latin: "reptile" (reptilis), "mammal" (mammalis)) is a genus of opossum- to badger-sized gobiconodontid mammal containing two species, ''Repenomamus robustus'' and ''Repenomamus giganticus''. Both species are known from fossils found in China that date to the early Cretaceous period, about 125-123.2 million years ago. ''R. robustus'' is one of several Mesozoic mammals for which there is good evidence that it fed on vertebrates, including dinosaurs, though it is not possible to determine if it actively hunted live dinosaurs or scavenged dead ones. ''R. giganticus'' is among the largest mammals known from the Mesozoic era. Classification and discovery The fossils were recovered from the lagerstätte of the Yixian Formation in the Liaoning province of China, which is renowned for its extraordinarily well-preserved fossils of feathered dinosaurs. They have been specifically dated to 125–123.2 million years ago, during the Early Cretaceous period. ''Repenomamus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutriconodont
Eutriconodonta is an order of early mammals. Eutriconodonts existed in Asia, Africa, Europe, North and South America during the Jurassic and the Cretaceous periods. The order was named by Kermack ''et al.'' in 1973 as a replacement name for the paraphyletic Triconodonta. Traditionally seen as the classical Mesozoic small mammalian insectivores, discoveries over the years have shown them to be among the best examples of the diversity of mammals in this time period, including a vast variety of bodyplans, ecological niches and locomotion methods. Classification "Triconodonta" had long been used as the name for an order of early mammals which were close relatives of the ancestors of all present-day mammals, characterized by molar teeth with three main cusps on a crown that were arranged in a row. The group originally included only the family Triconodontidae and taxa that were later assigned to the separate family Amphilestidae, but was later expanded to include other taxa such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necromantis
''Necromantis'' is an extinct genus of bat that lived during the Eocene. Its fossils are found in the Quercy Phosphorites Formation of France and the Djebel Chambi in Tunisia. Specimens of ''Necromantis'' are notable for their large size and specialization towards a predatory lifestyle. History The type species, ''N. adichaster'', was first described by A. Weithofer in 1887 on the basis of fragmentary fossils from the Eocene deposits of the Quercy Phosphorites Formation. Weithofer did not designate a type specimen, simply describing a lower jaw. This material was later described in more detail by Pierre Revilliod in 1920, offering the holotype the number QW627. He described additional material, and classified it within five species: ''N. adichaster'', ''N. gerzei'', ''N. marandati'', ''N. planifrons'' and ''N. grandis''. More recently, E. Maitre has described the fossils in more detail. ''N. grandis'' and ''N. planifrons'' have been considered indistinguishable from ''N. ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyaenodontidae
Hyaenodontidae ("hyena teeth") is a family of extinct predatory mammals from extinct superfamily Hyaenodontoidea within extinct order Hyaenodonta. Hyaenodontids arose during the early Eocene and persisted well into the early Miocene. Fossils of this group have been found in Asia, North America and Europe. (1985): ''The Field Guide to Prehistoric Life.'' Facts on File Publications, New York. Classification and phylogeny Taxonomy * Family: †Hyaenodontidae ** Genus: †'' Boritia'' *** †''Boritia duffaudi'' ** Genus: †'' Neosinopa'' *** †''Neosinopa gobiensis'' ** Genus: †'' Praecodens'' *** †''Praecodens acutus'' ** Genus: †'' Preregidens'' *** †''Preregidens langebadrae'' ** Genus: †'' Protoproviverra'' *** †''Protoproviverra palaeonictides'' ** (unranked): †''Cynohyaenodon''/''Quercytherium'' clade *** Genus: †''Cynohyaenodon'' (paraphyletic genus) **** †''Cynohyaenodon cayluxi'' **** †''Cynohyaenodon lautricensis'' **** †''Cynohyaenodo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxyaenidae
Oxyaenidae ("sharp hyenas") is a family of extinct carnivorous placental mammals. Traditionally classified in order Creodonta, this group is now classified in its own order Oxyaenodonta ("sharp tooth hyenas") within clade Pan-Carnivora in mirorder Ferae. The group contains four subfamilies comprising fourteen genera. Oxyaenids were the first to appear during the late Paleocene in North America, while smaller radiations of oxyaenids in Europe and Asia occurred during the Eocene. Etymology The name of order Oxyaenodonta comes , name of hyena genus ''Hyaena'' and . The name of family Oxyaenidae comes , name of hyena genus ''Hyaena'' and taxonomic suffix ":wikt:-idae#Suffix, -idae". Description They were superficially cat-like mammals that plantigrade, walked on flat feet, in contrast to modern cats, which digitigrade, walk and run on their toes. Anatomically, characteristic features include a short, broad skull, deep jaws, and teeth designed for crushing rather than shearing, as in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Creodonta
Creodonta ("meat teeth") is a former order of extinct carnivorous placental mammals that lived from the early Paleocene to the late Miocene epochs in North America, Europe, Asia and Africa. Originally thought to be a single group of animals ancestral to the modern Carnivora, this order is now usually considered a polyphyletic assemblage of two different groups, the Oxyaenids and the Hyenodonts, not a natural group. Oxyaenids are first known from the Palaeocene of North America, while hyaenodonts hail from the Palaeocene of Africa. Creodonts were the dominant carnivorous mammals from , peaking in diversity and prevalence during the Eocene. The first large, obviously carnivorous mammals appeared with the radiation of the oxyaenids in the late Paleocene. During the Paleogene, "creodont" species were the most abundant terrestrial carnivores in the Old World. In Oligocene Africa, hyaenodonts were the dominant group of large flesh-eaters, persisting until the middle of the Miocene. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Carnivoran And Creodont Carnassials
Comparison or comparing is the act of evaluating two or more things by determining the relevant, comparable characteristics of each thing, and then determining which characteristics of each are similar to the other, which are different, and to what degree. Where characteristics are different, the differences may then be evaluated to determine which thing is best suited for a particular purpose. The description of similarities and differences found between the two things is also called a comparison. Comparison can take many distinct forms, varying by field: To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and in the arts. General usage Comparison is a natural activity, which even animals engage in when deci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borhyaenidae
Borhyaenidae is an extinct metatherian family of low-slung, heavily built predatory mammals in the order Sparassodonta. Borhyaenids are not true marsupials, but members of a sister taxon, Sparassodonta. Like most metatherians, borhyaenids and other sparassodonts are thought to have had a pouch to carry their offspring around. Borhyaenids had strong and powerful jaws, like those of the unrelated placentalians ''Hyaenodon'' and ''Andrewsarchus'', for crushing bones. Borhyaenids grew up to an average of long. ''Borhyaena'' is the type genus of this group. Originally, the borhyaenids were one of the most diverse groups of sparassodonts, including all species not originally included in the Thylacosmilidae. However, in recent years, with the elevation of most sparassodont subfamilies to family rank and the discovery that borhyaenids are more closely related to proborhyaenids and thylacosmilids than other sparassodonts, the family has been reduced to seven species in four genera. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thylacoleo Carnifex
''Thylacoleo'' ("pouch lion") is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the late Pleistocene (2 million to 46 thousand years ago). Some of these marsupial lions were the largest mammalian predators in Australia of their time, with ''Thylacoleo carnifex'' approaching the weight of a lioness. The estimated average weight for the species ranges from . Taxonomy The genus was first published in 1859, erected to describe the type species ''Thylacoleo carnifex''. The new taxon was established in examination of fossil specimens provided to Richard Owen. The familial alliance takes its name from this description, the so-called marsupial lions of Thylacoleonidae. The colloquial name "marsupial lion" alludes to the superficial resemblance to the placental lion and its ecological niche as a large predator. ''Thylacoleo'' is not closely related to the modern lion (''Panthera leo''). Genus: ''Thylacoleo'' (''Thylacopardus'') – Australia' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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