|
Ferugliotheriidae
Ferugliotheriidae is one of three known families in the order Gondwanatheria, an enigmatic group of extinct mammals. Gondwanatheres have been classified as a group of uncertain affinities or as members of Multituberculata, a major extinct mammalian order. The best-known representative of Ferugliotheriidae is the genus '' Ferugliotherium'' from the Late Cretaceous epoch in Argentina. A second genus, '' Trapalcotherium'', is known from a single tooth, a first lower molariform ( molar-like tooth), from a different Late Cretaceous Argentinean locality. Another genus known from a single tooth (in this case, a fourth lower premolar), ''Argentodites'', was first described as an unrelated multituberculate, but later identified as possibly related to ''Ferugliotherium''. Finally, a single tooth from the Paleogene of Peru, LACM 149371, perhaps a last upper molariform, and a recent specimen from Mexico, may represent related animals. Ferugliotheriids are known from isolated, low-crowned ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwanatheria
Gondwanatheria is an extinct group of mammaliaforms that lived in parts of Gondwana, including Madagascar, India, South America, Africa and Antarctica during the Upper Cretaceous through the Paleogene (and possibly much earlier, if '' Allostaffia'' is a member of this group). Until recently, they were known only from isolated teeth, a few lower jaws, two partial skulls and one complete cranium. They are generally considered to be closely related to the multituberculates and likely the euharamiyidians, well known from the Northern Hemisphere, with which they form the clade Allotheria. Classification For several decades the affinities of the group were not clear, being first interpreted as early xenarthrans, or "toothless" mammals similar to the modern anteater. A variety of studies have placed them as allotheres related to multituberculates, possibly even true multituberculates, closer to cimolodonts than " plagiaulacidans" are. However, a more recent study recovered th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trapalcotherium
''Trapalcotherium'' is a fossil mammal from the Cretaceous of Argentina in the family Ferugliotheriidae. The single species, ''T. matuastensis'', is known from one tooth, a first lower molar. It is from the Allen Formation, which is probably Maastrichtian in age, and was first described in 2009. The tooth bears two rows of cusps, one at the inner (lingual) side and the other at the outer (labial) side, which are connected by transverse ridges separated by deep valleys. This pattern is reminiscent of ''Ferugliotherium'', a gondwanathere mammal from similarly aged deposits in Argentina, and ''Trapalcotherium'' is therefore recognized as a member of the same family Ferugliotheriidae. Ferugliotheriidae is one of two families of gondwanatheres, an enigmatic group without close relationships to any living mammals. Discovery and context The only known fossil of ''Trapalcotherium'' was found at Cerro Tortuga in Río Negro Province, southern Argentina. This locality is in the Allen For ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferugliotherium
''Ferugliotherium'' is a genus of fossil mammals in the family Ferugliotheriidae from the Campanian and/or Maastrichtian period (Late Cretaceous; around 70 million years ago) of Argentina. It contains a single species, ''Ferugliotherium windhauseni'', which was first described in 1986. Although originally interpreted on the basis of a single brachydont (low- crowned) molar as a member of Multituberculata, an extinct group of small, rodent-like mammals, it was recognized as related to the hypsodont (high-crowned) Sudamericidae following the discovery of additional material in the early 1990s. After a jaw of the sudamericid ''Sudamerica'' was described in 1999, these animals (collectively known as Gondwanatheria) were no longer considered to be multituberculates and a few fossils that were previously considered to be ''Ferugliotherium'' were assigned to unspecified multituberculates instead. Since 2005, a relationship between gondwanatheres and multituberculates has again received ... [...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] |
LACM 149371
LACM 149371 (Natural History Museum of Los Angeles County specimen 149371)Goin et al., 2004, p. 145 is an enigmatic fossil mammalian tooth from the Paleogene (66 to 23 million years ago, mya) of Peru. It is from the Santa Rosa fossil site, which is of uncertain age but possibly late Eocene (55 to 34 mya) or Oligocene (34 to 23 mya). The tooth is poorly preserved and may have been degraded by acidic water or because it passed through a predator's digestive tract. Its largest dimension is 2.65 mm. It is triangular in shape and bears six cusps that surround the middle of the tooth, where there are three basins (fossae). Crests connects the cusps and separate the fossae. The microscopic structure of the enamel is poorly preserved. LACM 149371 was described in 2004 by Francisco Goin and colleagues, who tentatively interpreted the tooth as a left last upper molar. Although they saw similarities with South American ungulates, some early rodents, and multituberculates, they believ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexico
Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Mexico covers ,Mexico '' The World Factbook''. . making it the world's 13th-largest country by area; with approximately 12 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachydont
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 tooth", from ''mola'', millstone and ''dens'', tooth. Molars show a great deal of diversity in size and shape across mammal groups. The third molar of humans is sometimes vestigial. Human anatomy In humans, the molar teeth have either four or five cusps. Adult humans have 12 molars, in four groups of three at the back of the mouth. The third, rearmost molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the front of the gum at about the age of 20, although this varies from individual to individual. Race can also affect the age at which this occurs, with statistical variations between groups. In some cases, it may not even erupt at all. The human mouth contains upper (maxillary) and lower (mandibu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incisor
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whereas armadillos have none. Structure Adult humans normally have eight incisors, two of each type. The types of incisor are: * maxillary central incisor (upper jaw, closest to the center of the lips) * maxillary lateral incisor (upper jaw, beside the maxillary central incisor) * mandibular central incisor (lower jaw, closest to the center of the lips) * mandibular lateral incisor (lower jaw, beside the mandibular central incisor) Children with a full set of deciduous teeth (primary teeth) also have eight incisors, named the same way as in permanent teeth. Young children may have from zero to eight incisors depending on the stage of their tooth eruption and tooth development. Typically, the mandibular central incisors erupt first, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Procumbent
This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnifying lens. This page provides help in understanding the numerous other pages describing plants by their various taxa. The accompanying page— Plant morphology—provides an overview of the science of the external form of plants. There is also an alphabetical list: Glossary of botanical terms. In contrast, this page deals with botanical terms in a systematic manner, with some illustrations, and organized by plant anatomy and function in plant physiology. This glossary primarily includes terms that deal with vascular plants ( ferns, gymnosperms and angiosperms), particularly flowering plants (angiosperms). Non-vascular plants ( bryophytes), with their different evolutionary background, tend to have separate terminology. Although plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Enamel
Tooth enamel is one of the four major tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the crown. The other major tissues are dentin, cementum, and dental pulp. It is a very hard, white to off-white, highly mineralised substance that acts as a barrier to protect the tooth but can become susceptible to degradation, especially by acids from food and drink. Calcium hardens the tooth enamel. In rare circumstances enamel fails to form, leaving the underlying dentin exposed on the surface. Features Enamel is the hardest substance in the human body and contains the highest percentage of minerals (at 96%),Ross ''et al.'', p. 485 with water and organic material composing the rest.Ten Cate's Oral Histology, Nancy, Elsevier, pp. 70–94 The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. Enamel is formed on the tooth while the tooth develops wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peru
, image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Firm and Happy for the Union" , national_anthem = "National Anthem of Peru" , march = "March of Flags" , image_map = PER orthographic.svg , map_caption = , image_map2 = , capital = Lima , coordinates = , largest_city = capital , official_languages = Peruvian Spanish, Spanish , languages_type = Co-official languages , languages = , ethnic_groups = , ethnic_groups_year = 2017 , demonym = Peruvians, Peruvian , government_type = Unitary state, Unitary Semi-presidential system, semi-presidential republic , leader_title1 = President of Peru, President ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
