|
Triconodontid
Triconodontidae is an extinct family of small, carnivorous mammals belonging to the order Eutriconodonta, endemic to what would become Asia, Europe, North America and probably also Africa and South America during the Jurassic through Cretaceous periods at least from 190–66 mya. Triconodontids can be distinguished from other eutriconodonts by the shape of their molars, which bore three main cusps of roughly equal size. During occlusion, the upper and lower molars interlocked tightly, producing a self-sharpening cutting edge. Historically, the triconodontids were thought to have a different occlusion pattern than other eutriconodonts, with the middle cusp of the lower molar (cusp a) fitting between the middle cusp (cusp A) and the front cusp (cusp B) of the upper molar, as in the basal mammaliaform ''Morganucodon''. However, a 2020 study on '' Priacodon'' suggests that triconodontids occluded their molars in the same manner as other eutriconodonts (so-called "embrasure occlusio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiconodon
''Meiconodon'' is an extinct genus of alticonodontine triconodontid which existed in China during the early Cretaceous period (Aptian/Albian age). It was described by Nao Kusuhashi, Yaoming Hu, Yuanqing Wang, Satoshi Hirasawa and Hiroshige Matsuoka in 2009 and the type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ... is ''Meiconodon lii''. References Cretaceous mammals Triconodontidae Fossil taxa described in 2009 Extinct mammals of Asia Taxa named by Nao Kusuhashi Taxa named by Yaoming Hu Taxa named by Yuanqing Wang Taxa named by Satoshi Hirasawa Taxa named by Hiroshige Matsuoka Prehistoric mammal genera {{cretaceous-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutriconodonta
Eutriconodonta is an order (biology), order of early mammals. Eutriconodonts existed in Asia (including Insular India, pre-contact India), Africa, Europe, North America, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astroconodon
''Astroconodon'' is an extinct genus of mammal from the Cretaceous of North America. Part of Eutriconodonta, it was a small sized predator, either a terrestrial insectivore and carnivore, or a semi-aquatic piscivore. It is the first Cretaceous eutriconodont found.B. Patterson. 1951. Early Cretaceous mammals from northern Texas. American Journal of Science 249:31-46Zofia Kielan-Jaworowska, Richard L. Cifelli, Zhe-Xi Luo (2004). "Chapter 7: Eutriconodontans". Mammals from the Age of Dinosaurs: origins, evolution, and structure. New York: Columbia University Press. pp. 216–248. . Description The type species is ''A. denisoni''. Known from the Antlers Formation, its type specimen, ''FMNH PM 542'', was first described by Bryan Patterson in 1951. It is a generally rather common species, known from a large quantity of isolated teeth, exhibiting a high degree of variability. Bob H. Slaughter, Astroconodon, the Cretaceous Triconodont, Journal of Mammalogy, Vol. 50, No. 1 (Feb., 1969), p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arundelconodon
''Arundelconodon'' is an extinct genus of mammal of the family Triconodontidae, containing the species ''Arundelconodon hottoni''. It is known from multiple dental remains from the Arundel Clay in Maryland, United States, dated to the Early Cretaceous. The remains consist jawbone fragments with premolar, Molar (tooth), molar, and canine teeth. Its anatomic features are intermediate between Jurassic and later Cretaceous triconodonts. The deposits from which it is known represent either a fringe swamp or a floodplain, likely near a coast. Discovery and naming The type specimen of the genus ''Arundelconodon'' was Species description, described by paleontologist Richard L. Cifelli and colleagues in 1999. The type species was named ''Arundelcodon hottoni''. Their description was based on a "remarkably complete" jaw from the Arundel Clay of Maryland, United States. The genus name comes from the words ''Arundel'', in reference to the Arundel Clay where the remains were found (itself na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnivorous
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly muscle, fat and other soft tissues) as food, whether through predation or scavenging. Nomenclature Mammal order The technical term for mammals in the order Carnivora is ''carnivoran'', and they are so-named because most member species in the group have a carnivorous diet, but the similarity of the name of the order and the name of the diet causes confusion. Many but not all carnivorans are meat eaters; a few, such as the large and small cats (Felidae) are ''obligate'' carnivores (see below). Other classes of carnivore are highly variable. The ursids (bears), for example: while the Arctic polar bear eats meat almost exclusively (more than 90% of its diet is meat), almost all other bear species are omnivorous, and one species, the gia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jugulator Amplissimus
''Jugulator'' is an extinct genus of mammals from the Cretaceous of North America. It contains one species, ''Jugulator amplissimus''. A eutriconodont, it is known from the Cedar Mountain Formation, and is both a large sized and possibly ecologically specialised taxon, showcasing the diversity of mammals in the Mesozoic. Description ''Jugulator'' is known primarily from isolated teeth and dentaries. The species is most distinctive in regards to its large size, being among the largest mammals in the region, some lower molars exceeding 5 mm in length and with an estimated body weight of about 750 g. The medial lower incisor is greatly enlarged, with a mitten-shaped crown that bears sharp cutting surfaces. Phylogeny Always recognised as a triconodontid eutriconodont, the most recent phylogenetic studies recover ''Jugulator'' as the sister taxon of a clade comprising ''Volaticotherium'', ''Ichthyoconodon'', '' Triconolestes'', and ''Argentoconodon'', known as Volaticotherini.A. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alticonodon
''Alticonodon'' is a genus of extinct mammal from the Late Cretaceous of North America. It is one of the geologically youngest known eutriconodonts, and is a fairly more specialised animal than earlier representatives of this clade.R. C. Fox. 1969. Studies of Late Cretaceous vertebrates. III. A triconodont mammal from Alberta. ''Canadian Journal of Zoology'' 47:1253-1256 Description ''Alticonodon'' is currently a monotypic genus, represented exclusively by ''A. lindoei''. It is known from the Milk River Formation deposits of the early Campanian of Alberta, Canada. It is known from two specimens: a dentary fragment bearing two molars, and an isolated lower last molar. Classification ''Alticonodon'' has been consistently recovered as a triconodontid, and more specifically as an alticonodontine, though the latter term may be redundant in relation to the rest of Triconodontidae. Biology Compared to earlier eutriconodonts, ''Alticonodon'' has molars better specialised for shearing. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volaticotherini
Volaticotherini is a clade of eutriconodont mammals from the Mesozoic. In addition to the type genus '' Volaticotherium'', it includes the genera '' Argentoconodon'', '' Ichthyoconodon'', and potentially '' Triconolestes''. Since most remains are primarily teeth, they are foremostly diagnosticated by their highly distinctive molars. However, the remains of one species, '' Volaticotherium antiquum'', show that at least some members of this clade were capable of gliding. and '' Argentoconodon'' shares similar post-cranial features that also indicate aerial locomotion. As such, this clade contains some of the oldest known aerial mammals, alongside the various gliding haramiyidans. Definition Volaticotherini is phylogenetically defined as the clade derived from the most recent common ancestor of ''Argentoconodon'', ''Ichthyoconodon,'' and ''Volaticotherium''. History '' Ichthyoconodon'' was the first described member of this group, back in 1995, previously usually ranked among eut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the south and west by the Pacific Ocean. The region includes Middle America (Americas), Middle America (comprising the Caribbean, Central America, and Mexico) and Northern America. North America covers an area of about , representing approximately 16.5% of Earth's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa, and the list of continents and continental subregions by population, fourth-largest continent by population after Asia, Africa, and Europe. , North America's population was estimated as over 592 million people in list of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surface area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With nearly billion people as of , it accounts for about of the world's human population. Demographics of Africa, Africa's population is the youngest among all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Based on 2024 projections, Africa's population will exceed 3.8 billion people by 2100. Africa is the least wealthy inhabited continent per capita and second-least wealthy by total wealth, ahead of Oceania. Scholars have attributed this to different factors including Geography of Africa, geography, Climate of Africa, climate, corruption, Scramble for Africa, colonialism, the Cold War, and neocolonialism. Despite this lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilisations. Its 4.7 billion people constitute roughly 60% of the world's population. Asia shares the landmass of Eurasia with Europe, and of Afro-Eurasia with both Europe and Africa. In general terms, it is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a social constructionism, historical and cultural construct, as there is no clear physical and geographical separation between them. A commonly accepted division places Asia to the east of the Suez Canal separating it from Africa; and to the east of the Turkish straits, the Ural Mountains an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion of the Americas. South America is bordered on the west by the Pacific Ocean, on the north and east by the Atlantic Ocean, and to the south by the Drake Passage; North America and the Caribbean Sea lie to the northwest. The continent includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territory, dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one administrative division, internal territory: French Guiana. The Dutch Caribbean ABC islands (Leeward Antilles), ABC islands (Aruba, Bonaire, and Curaçao) and Trinidad and Tobago are geologically located on the South-American continental shel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
