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Megahippus
''Megahippus'' is an extinct genus of large Anchitheriine horses found throughout the southern portion of the United States during the middle Miocene. The animal represents one of the latest low-crowned horses, overlapping in time with more derived high-crowned horses. Description Dentition Though generally similar to other genera within the subfamily, ''Megahippus'' is unique in the presence of a well defined ridge across the inner edge of the premolars 1-3 along with the presence of large, frontward-facing lower incisors. Unlike the incisors of other anchitheriines like ''Hypohippus'', they would have been large and high-crowned.Between the two species, there is evidence of a trend of the animal's premolars shrinking over time with them being larger proportionally in M. mckennai. Both ''Megahippus'' and ''Hypohippus'' show a general trend in the increase in frequency of conchets in their upper cheek teeth potentially due to the segregation of the section when compared to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchitheriinae
The Anchitheriinae are an extinct subfamily of the Perissodactyla family Equidae, the same family which includes modern horses, zebras and donkeys. This subfamily is more primitive than the living members of the family. The group first appeared with '' Mesohippus'' in North America during the middle Eocene and thrived until the late Miocene. The subfamily continued in Eurasia with the genus '' Sinohippus'' until the early Pliocene, when it finally became extinct. This subfamily are considered browsers with their more ancestral low-crowned molars, in contrast with the modern, specialized grazer species of modern Equinae. During the Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ..., this subfamily experienced an increase in tooth abrasion without any corresponding c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypohippus
''Hypohippus'' (Greek: "under" (hypos), "horse" (hippos)) is an extinct genus of three-toed horse, which lived 17–11 million years ago. It was the largest anchitherine equid about the size of a modern domestic horse, at and long. It was a long-necked, high-shouldered browser with sub-hypsodont, lophodont (rhino-like) dentition, that fed on the tough vegetation of forest understory and shrubs. Its deep preorbital fossae and retraction of the nasal notch hint at the presence of a long, muscular and prehensile upper lip that would aid during selective browsing. Overall its ecology would have been more comparable to modern okapi than to grazing horses. Fossils of it have been found in Nebraska, Colorado, and Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an .... Image:Hypohi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barstovian
The Barstovian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 16,300,000 to 13,600,000 years BP, a period of . It is usually considered to overlap the Langhian and Serravallian stages of the Middle Miocene. The Barstovian is preceded by the Hemingfordian and followed by the Clarendonian NALMA stages. The Barstovian can be further divided into the substages of: * late Late Barstovian: Lower boundary source of the base of the Langhian (approximate) * early Late Barstovian: Base of the Langhian (approximate) * early/lower Barstovian: Upper boundary source: base of Clarendonian (approximate) Correlations The Barstovian (15.97 to 13.6 Ma) correlates with: * SALMA ** Colloncuran (15.5-13.8 Ma) [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarendonian
The Clarendonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 13,600,000 to 9,000,000 years BP, a period of . It is usually considered to overlap the Serravallian age of the Middle Miocene and the Tortonian age of the Late Miocene. The Clarendonian is preceded by the Barstovian and followed by the Hemphillian The Hemphillian North American Stage on the geologic timescale is a North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered t ... NALMA stages. Subdivisions The Clarendonian can be further divided into the substages of: * Late/Upper Clarendonian: Lower boundary source of the base of the Clarendonian (approximate) * Early/Lower Clarendonian (shares lower boundary) References Miocene life Miocene animals of North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and Ape, hominoids into Eurasia. During the late Miocene, the conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchitherium
''Anchitherium'' (meaning ''near beast'') is a genus of Extinction, extinct Equidae, equid with a three-toed hoof. ''Anchitherium'' was a browsing (predation), browsing (leaf eating) horse that originated in the early Miocene of North America, being found as far south as Panama, and subsequently dispersed to Europe and Asia,(in Chinese with English summary).MacFadden, B.J. 2001. Three-toed browsing horse ''Anchitherium clarencei'' from the early Miocene (Hemingfordian) Thomas Farm, Florida. Bulletin of the Florida Museum of Natural History, 43(3):79-109. where it gave rise to the larger bodied genus ''Sinohippus''. It was around high at the shoulder, and probably represented a side-branch of horse evolution that left no modern descendants. References {{Taxonbar, from=Q542119 Anchitheriinae Miocene horses Prehistoric placental genera Miocene mammals of North America Miocene mammals of Asia Miocene mammals of Europe Fossil taxa described in 1844 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeohippus
''Archaeohippus'' (Greek: "ancient" (archaios), "horse" (hippos)) is an extinct three-toed member of the family Equidae known from fossils of early Oligocene to middle Miocene age. The genus is noted for several distinct skeletal features. The skull possesses deeply pocketed fossa in a notably long preorbital region. The genus is considered an example of phyletic dwarfism with adults estimated at being on average 20 kilograms in weight. This is in contrast to the most common equid of the period, ''Miohippus''. Characters of the teeth show a mix of both primitive and advanced traits. The advanced traits are very similar to those shown in the genus ''Parahippus''. The noted similarities of ''Archaeohippus'' and ''Parahippus'' show them to be descended from a common ancestor. They are considered sister species. Taxonomic history The first species to be named was found in the Miocene Mascall Fauna of Cottonwood Creek, Oregon. Named '' Anchitherium ultimus'' the species was descri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equus (genus)
''Equus'' () is a genus of mammals in the perissodactyl family (biology), family Equidae, which includes wild horse, horses, Asinus, asses, and zebras. Within the Equidae, ''Equus'' is the only recognized Extant taxon, extant genus, comprising seven living species. Like Equidae more broadly, ''Equus'' has numerous extinct species known only from fossils. The genus originated in North America and dispersed into the Old World and South America during the Early and Middle Pleistocene. Equinae, Equines are odd-toed ungulates with slender legs, long heads, relatively long necks, manes (erect in most subspecies), and long tails. All species are herbivorous, and mostly grazers, with simpler digestive systems than Ruminantia, ruminants but able to subsist on lower-quality vegetation. While the domestic horse and donkey (along with their feral horse, feral descendants) exist worldwide, wild equine populations are limited to Africa and Asia. Wild equine social systems are in two forms; a H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene Horses
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and hominoids into Eurasia. During the late Miocene, the connections between th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Placental Genera
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] |
Miocene Perissodactyla
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and hominoids into Eurasia. During the late Miocene, the connections between the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
