|
Pliohippus
''Pliohippus'' (Greek (, "more") and (, "horse")) is an extinct genus of Equidae, the horse family. ''Pliohippus'' arose in the middle Miocene, around 15 million years ago. The long and slim limbs of ''Pliohippus'' reveal a quick-footed steppe animal. While some specimens have one toe per leg, others have three (the main toe and two non-functional side toes). Until recently, because of its many anatomical similarities, ''Pliohippus'' was believed to be the ancestor of the present-day horse and its relatives in '' Equus''. Although ''Pliohippus'' clearly is an equid Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ... and thus related to ''Equus'', its skull had deep facial ''fossae'', a feature not found in any member of ''Equus''. Additionally, its teeth were strongly curved, unli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrohippus
''Astrohippus'' is an extinct member of the Equidae tribe Equini, the same tribe that contains the only living equid genus, '' Equus''. Fossil remains have been found in the central United States, Florida, and the Mexican states of Chihuahua, Jalisco, and Guanajuato. The fossils date in time from the oldest dating from the Barstovian in the Miocene to the youngest dating in the Hemphillian faunal stage of the early Pliocene. Based on study of the tooth morphology it is considered unlikely that ''Astrohippus'' could be an ancestor of modern horses, with the most likely ancestor of ''Astrohippus'' being '' Pliohippus''.MacFadden, B. J. (1984). "Astrohippus and Dinohippus". ''J. Vert. Paleon''. 4(2):273–283. The species '' Astrohippus ansae'' was originally described by W. D. Matthew and R. A. Stirton based on several cheek teeth found in the Coffee Ranch quarry, Hemphill County, Texas. This quarry has produced the remains of six other equid genera including ''Dinohippus'' a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashfall Fossil Beds
The Ashfall Fossil Beds of Antelope County in northeastern Nebraska are rare fossil sites of the type called lagerstätten that, due to extraordinary local conditions, capture an ecological "snapshot" in time of a range of well-preserved fossilized organisms. Ash from a Yellowstone hotspot eruption 10-12 million years ago created these fossilized bone beds. The ash depth was up to 1 foot. The site is protected as Ashfall Fossil Beds State Historical Park, a park that includes a visitor center with interpretive displays and working fossil preparation laboratory, and a protected ongoing excavation site, the Hubbard Rhino Barn, featuring fossil '' Teleoceras'' (native hippo-like ancestral rhinoceros) and ancestral horses. The Ashfall Fossil Beds are especially famous for fossils of mammals from the middle Miocene geologic epoch. The Ashfall Fossil Beds are stratigraphically part of the Serravallian-age Ogallala Group, within the Ash Hollow Formation. Bruneau-Jarbidge event ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equidae
Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The family evolved more than 50 million years ago, in the Eocene epoch, from a small, multi-toed ungulate into larger, single-toed animals. All Extant taxon, extant species are in the genus ''Equus (genus), Equus'', which originated in North America. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families. It is more specifically grouped within the superfamily (taxonomy), superfamily Equoidea, the only other family being the extinct Palaeotheriidae. The term equid refers to any member of this family, including any equinae, equine. Evolution The oldest known fossils assigned to Equidae were found in North America, and date from the early Eocene epoch, 54 million years ago. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1874
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of ''Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before print. The ob ... [...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] |
Neogene Mammals Of North America
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of the Cenozoic and the eleventh period of the Phanerozoic. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). The earlier term Tertiary Period was used to define the span of time now covered by Paleogene and Neogene and, despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first humans (''H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transitional Fossils
A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. Because of the incompleteness of the fossil record, there is usually no way to know exactly how close a transitional fossil is to the point of divergence. Therefore, it cannot be assumed that transitional fossils are direct ancestors of more recent groups, though they are frequently used as models for such ancestors. In 1859, when Charles Darwin's ''On the Origin of Species'' was first published, the fossil record was poorly known. Darwin described the perceived lack of transitional fossils as "the most obvious and gravest objection which can be ... [...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] |
Pliocene Horses
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.33 to 2.58See the 2014 version of the ICS geologic time scale million years ago (Ma). It is the second and most recent epoch of the Period in the Cenozoic Era. The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2 ... [...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] |
Neohipparion
''Neohipparion'' (Greek: "new" (neos), "pony" (hipparion)) is an extinction, extinct genus of equid, from the Neogene (Miocene to Pliocene) of North America and Central America. Fossils of this horse have been found in Texas, Florida, Kansas, South Dakota, Montana, Nevada, Alabama, Oregon, and Mexico. This prehistoric species of equid grew up to lengths of long. In Florida, Neohipparion lived in a Savanna, savanna environment during the dry season but moved to a wet environment when it came time to mate. The average age of death for a newborn colt was 3.5 years, with a juvenile mortality rate of 64% during its first 2 years of existence. Its diet consisted of Poaceae, grasses, C3 plants, C3 and C4 plants. Δ13C, δ13C values from ‘’N. eurystyle’’ fossils found in Florida indicate that it fed almost exclusively on C4 grasses. References Miocene horses Pliocene horses Prehistoric placental genera Miocene mammals of North America Pliocene mammals of North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
