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Stegoloxodon
''Stegoloxodon'' is an extinct genus of dwarf elephant known from the Early Pleistocene of Indonesia. It contains two species, ''S. indonesicus'' from Java, and ''S. celebensis'' from Sulawesi. Its relationship with other elephants is uncertain. Taxonomy ''S. celebensis'' was originally described as ''Archidiskodon'' ''celebensis'' in 1949 by Dirk Albert Hooijer. ''S. indonesicus'' was originally described by Miklós Kretzoi based on a molar found near Bumiayu, originally attributed to ''Elephas planifrons'', who coined the genus ''Stegoloxodon'' to contain the species. A 1973 paper argued for the synonymy of the two species,Maglio, V.J. (1973). ''Origin and evolution of the Elephantidae''. Transactions of the American Philosophical Society Philadelphia Volume 63. American Philosophical Society, Philadelphia. Pp. 149 which was later rejected, though they are usually considered closely related. Some later papers referred the species to ''Elephas''. A paper by Paul Yves Sondaar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dwarf Elephant
Dwarf elephants are prehistoric members of the order Proboscidea which, through the process of allopatric speciation on islands, evolved much smaller body sizes (around shoulder height) in comparison with their immediate ancestors. Dwarf elephants are an example of insular dwarfism, the phenomenon whereby large terrestrial vertebrates (usually mammals) that colonize islands evolve dwarf forms, a phenomenon attributed to adaptation to resource-poor environments and lack of predation and competition. Fossil remains of dwarf elephants have been found on the Mediterranean islands of Cyprus, Malta, Crete, Sicily, Sardinia, the Cyclades Islands and the Dodecanese Islands, which are mostly members of the genus ''Palaeoloxodon'', descending from the large tall straight-tusked elephant (''Palaeoloxodon antiquus'') of mainland Europe'','' though two species represent dwarf mammoths. Dwarf species of elephants and '' Stegodon'' have been found on the islands of Indonesia and the Philippi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elephas Planifrons
''Elephas planifrons'' is an extinct species of elephant, known from the Late Pliocene-Early Pleistocene of the Indian subcontinent and probably South East Asia (Java, Indonesia). Description The number of lamellae on the third molars is typically in the range of 11 to 15. Members of the species retained permanent premolars, unlike living Asian elephants. Ecology Isotopic evidence suggests that the species had a grazing based diet. Evolution ''Elephas planifrons'' represents one of the earliest dispersals of elephants outside of Africa, first arriving on the Indian subcontinent around 3.6 million years ago (though some authors have suggested a much earlier age over 5 million years ago). The date of the last record of the species is highly uncertain, with estimates ranging from 2.5 million to 800,000 years ago. While only definitively reported from the Indian subcontinent, possible ''E. planifrons'' remains have been reported from Indonesia, and the species may be closely relat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premolars
The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered transitional teeth during chewing, or mastication. They have properties of both the canines, that lie anterior and molars that lie posterior, and so food can be transferred from the canines to the premolars and finally to the molars for grinding, instead of directly from the canines to the molars. Human anatomy The premolars in humans are the maxillary first premolar, maxillary second premolar, mandibular first premolar, and the mandibular second premolar. Premolar teeth by definition are permanent teeth distal to the canines, preceded by deciduous molars. Morphology There is always one large buccal cusp, especially so in the mandibular first premolar. The lower seco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic Mammals Of Asia
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three geological eras of the Phanerozoic Eon, preceded by the Mesozoic and Paleozoic. The Cenozoic started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians (placentals) in the Northern Hemisphere and the metatherians (marsupials, now mainly restricted to Australia and to some extent South America) in the Southern Hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so that large mamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene Extinctions
The Late Pleistocene to the beginning of the Holocene saw the extinction of the majority of the world's megafauna, typically defined as animal species having body masses over , which resulted in a collapse in faunal density and diversity across the globe. The extinctions during the Late Pleistocene are differentiated from previous extinctions by their extreme size bias towards large animals (with small animals being largely unaffected), and widespread absence of ecological succession to replace these extinct megafaunal species, and the regime shift of previously established faunal relationships and habitats as a consequence. The timing and severity of the extinctions varied by region and are generally thought to have been driven by humans, climatic change, or a combination of both. Human impact on megafauna populations is thought to have been driven by hunting ("overkill"), as well as possibly environmental alteration. The relative importance of human vs climatic factors in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Elephants
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinomastodon
''Sinomastodon'' ("Chinese mastodont") is an extinct gomphothere genus (of order Proboscidea) known from the Late Miocene to Early Pleistocene of Asia, including China, Japan, Thailand, Myanmar, Indonesia and probably Kashmir. Extinct animals of Indonesia Description ''Sinomastodon'', in comparison to earlier gomphotheres, had a shortened (brevirostrine) lower jaw that lacked permanent tusks/incisors. The skull was proportionally relatively short. The upper tusks, which are circular in cross-section, are upward curving and lack enamel bands. The molar teeth were triolophodont and bunodont. One individual of ''S. hanjiangensis,'' suggested to about 30-years-old, is estimated to have been about tall and weighed . Taxonomy and evolution The taxonomic position of ''Sinomastodon'' is disputed. Some authors suggest that ''Sinomastodon'' originated from North American gomphotheres that migrated into Asia. Position according to Mothé et al. 2016 supporting this hypothesis, showing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegodon
''Stegodon'' (from the Ancient Greek στέγω (''stégō''), meaning "to cover", and ὀδούς (''odoús''), meaning "tooth", named for the distinctive ridges on the animal's molars) is an extinct genus of proboscidean, related to elephants. It was originally assigned to the family Elephantidae along with modern elephants but is now placed in the extinct family Stegodontidae. Like elephants, ''Stegodon'' had teeth with plate-like lophs that are different from those of more primitive proboscideans like gomphotheres and mammutids. Fossils of the genus are known from Africa and across much of Asia, as far southeast as Timor (with a single record in southeast Europe). The oldest fossils of the genus are found in Late Miocene strata in Asia, likely originating from the more archaic ''Stegolophodon,'' subsequently migrating into Africa. While the genus became extinct in Africa during the Pliocene, ''Stegodon'' persisted in South, Southeast and Eastern Asia into the Late Pleisto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C3 Carbon Fixation
carbon fixation is the most common of three metabolic pathways for carbon fixation in photosynthesis, the other two being and CAM. This process converts carbon dioxide and ribulose bisphosphate (RuBP, a 5-carbon sugar) into two molecules of 3-phosphoglycerate through the following reaction: :CO2 + H2O + RuBP → (2) 3-phosphoglycerate This reaction was first discovered by Melvin Calvin, Andrew Benson and James Bassham in 1950. C3 carbon fixation occurs in all plants as the first step of the Calvin–Benson cycle. (In and CAM plants, carbon dioxide is drawn out of malate and into this reaction rather than directly from the air.) Plants that survive solely on fixation ( plants) tend to thrive in areas where sunlight intensity is moderate, temperatures are moderate, carbon dioxide concentrations are around 200 ppm or higher, and groundwater is plentiful. The plants, originating during Mesozoic and Paleozoic eras, predate the plants and still represent approximatel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Browsing (herbivory)
Browsing is a type of herbivory in which a herbivore (or, more narrowly defined, a folivore) feeds on leaves, soft Shoot (botany), shoots, or fruits of high-growing, generally woody plants such as shrubs. This is contrasted with Grazing (behaviour), grazing, usually associated with animals feeding on grass or other lower vegetations. Alternatively, grazers are animals eating mainly grass, and browsers are animals eating mainly non-grasses, which include both woody and herbaceous Dicotyledon, dicots. In either case, an example of this dichotomy are goats (which are primarily browsers) and Domestic sheep, sheep (which are primarily grazers). Browse The plant material eaten is known as ''browse'' and is in nature taken directly from the plant, though owners of livestock such as goats and deer may cut twigs or branches for feeding to their stock. In temperate regions, owners take browse before leaf fall, then dry and store it as a winter feed supplement. In time of drought, herdsme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scripta Geologica
''Scripta Geologica'' is a peer-reviewed scientific journal that publishes on vertebrate and invertebrate palaeontology, palaeobotany/palynology, stratigraphy, petrology, and mineralogy, including gemmology with a focus on systematics. It is published by the Dutch National Museum of Natural History, Naturalis. ''Scripta Geologica'' was established in 1881 as ''Sammlungen des geologischen Reichsmuseums in Leiden'' (1881-1923), changing its title to ''Leidse Geologische Mededelingen'' in 1925 (originally spelled as ''Leidsche Geologische Mededeelingen''). From 1971, the latter title was published in parallel with ''Scripta Geologica'' until they were merged in 1985. Abstracting and indexing ''Scripta Geologica'' is abstracted and indexed in PASCAL, GeoBase, GeoAbstracts and GeoRef __NOTOC__ The GeoRef database is a bibliographic database that indexes scientific literature in the geosciences, including geology. Coverage ranges from 1666 to the present for North American literat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandibular Symphysis
In human anatomy, the facial skeleton of the skull the external surface of the mandible is marked in the median line by a faint ridge, indicating the mandibular symphysis (Latin: ''symphysis menti'') or line of junction where the two lateral halves of the mandible typically fuse in the first year of life (6–9 months after birth). It is not a true symphysis as there is no cartilage between the two sides of the mandible. This ridge divides below and encloses a triangular eminence, the mental protuberance, the base of which is depressed in the center but raised on either side to form the mental tubercle. The lowest (most inferior) end of the mandibular symphysis — the point of the chin — is called the "menton". It serves as the origin for the geniohyoid and the genioglossus muscles. Other animals Solitary mammalian carnivores that rely on a powerful canine bite to subdue their prey have a strong mandibular symphysis, while pack hunters delivering shallow bites have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
