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Olbitherium
''Olbitherium'' is an extinct mammal of the order Perissodactyla (an early ancestor of modern-day horses, rhinos, and tapirs) from the early Eocene epoch of Shandong, China. Description and classification ''Olbitherium'' was originally described from lower and upper jaw fragments and several teeth found in the Wutu Formation of Shandong Province. The limited material of ''Olbitherium'' shares similarities with several ungulate groups. According to Tong ''et al.'', the upper cheek teeth show similarities to early Perissodactyls, as well as the hyracoid ''Seggeurius'', while the lower cheek teeth more closely resemble those of phenacodontids, such as ''Ectocion'', ''Phenacodus'', and ''Copecion''. Due to these conflicting similarities, Tong ''et al.'' placed ''Olbitherium'' as ''incertae sedis'' within the Phenacodonta, a grouping of Perissodactyla, "Condylarthra", and Hyracoidea in McKenna's 1975 classification, and suggested that ''Olbitherium'' represents an intermediate sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Eocene
In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian is consistent with the lower Eocene. Events The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, the Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian. Stratigraphic definition The Ypresian Stage was introduced in scientific literature by Belgium, Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after the Flanders, Flemish city of Ypres in Belgium (spelled ''Ieper'' in Dutch). The definitions of the original stage were totally different from the modern ones. The Ypresi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copecion
''Copecion'' was a genus of early herbivorous mammals that was part of the family Phenacodontidae Phenacodontidae is an extinct family of large herbivorous mammals traditionally placed in the “wastebasket taxon” Condylarthra, which may instead represent early-stage perissodactyls. They lived in the Paleocene and Eocene epochs (about 6 ....P. D. Gingerich. 1989. "New earliest Wasatchian mammalian fauna from the Eocene of northwestern Wyoming: composition and diversity in a rarely sampled high-floodplain assemblage". University of Michigan Papers on Paleontology 28:1-97. References External links * Condylarths Paleocene mammals of North America Eocene mammals of North America Eocene genus extinctions Prehistoric placental genera Fossil taxa described in 1989 {{paleo-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Perissodactyla
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Horses
The evolution of the horse, a mammal of the family Equidae, occurred over a geologic time scale of 50 million years, transforming the small, dog-sized, forest-dwelling ''Eohippus'' into the modern horse. Paleozoologists have been able to piece together a more complete outline of the evolutionary lineage of the modern horse than of any other animal. Much of this evolution took place in North America, where horses originated but became extinct about 10,000 years ago. The horse belongs to the order Perissodactyla (odd-toed ungulates), the members of which all share hooved feet and an odd number of toes on each foot, as well as mobile upper lips and a similar tooth structure. This means that horses share a common ancestry with tapirs and rhinoceroses. The perissodactyls arose in the late Paleocene, less than 10 million years after the Cretaceous–Paleogene extinction event. This group of animals appears to have been originally specialized for life in tropical forests, but whereas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homogalax
''Homogalax'' (from the Greek "ομογάιαξ") is an extinct genus of tapir-like odd-toed ungulate. It was described on the basis of several fossil finds from the northwest of the USA, whereby the majority of the remains come from the state of Wyoming. The finds date to the Lower Eocene between 56 and 48 million years ago. In general, ''Homogalax'' was very small, only reaching the weight of today's peccaries, with a maximum of 15 kg. Phylogenetic analysis suggests the genus to be a basal member of the clade that includes today's rhinoceros and tapirs (collectively called Ceratomorpha). In contrast to these, ''Homogalax'' was adapted to fast locomotion.Holbrook, LT; Lucas, SG; and Emry, RJ; "Skulls of the Eocene Perissodactyls (Mammalia) ''Homogalax'' and ''Isectolophus''." ''Journal of Vertebrate Paleontology 24''. (4) 951-956. Description ''Homogalax'' was a small representative of the basal odd-toed ungulates. In general, it resembled other, basal forms of the order P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isectolophidae
Isectolophidae is a potentially paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ... family of browsing, herbivorous, mammals in the Perissodactyla suborder Ancylopoda that show long, curved and cleft claws. Chalicotheres Prehistoric mammal families {{paleo-oddtoedungulate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (phylogeny)
In phylogenetics, basal is the direction of the ''base'' (or root) of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a ' key innovation' implies some degree of correlation between evolutionary innovation and diversification. However, such a correlation does not make a given case predicable, so ancestral characters should not be imputed to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyracoidea
Hyraxes (), also called dassies, are small, thickset, herbivorous mammals in the order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Typically, they measure between long and weigh between . They are superficially similar to pikas and marmots, but are more closely related to elephants and sea cows. Hyraxes have a life span from 9 to 14 years. Five extant species are recognised: the rock hyrax (''Procavia capensis'') and the yellow-spotted rock hyrax (''Heterohyrax brucei''), which both live on rock outcrops, including cliffs in Ethiopia and isolated granite outcrops called koppies in southern Africa; the western tree hyrax (''Dendrohyrax dorsalis''), southern tree hyrax (''D. arboreus''), and eastern tree hyrax (''D. validus''). Their distribution is limited to Africa, except for ''P. capensis'', which is also found in the Middle East. Characteristics Hyraxes retain or have redeveloped a number of primitive mammalian characteristics; in particular, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condylarthra
Condylarthra is an informal group – previously considered an order – of extinct placental mammals, known primarily from the Paleocene and Eocene epochs. They are considered early, primitive ungulates. It is now largely considered to be a wastebasket taxon, having served as a dumping ground for classifying ungulates which had not been clearly established as part of either Perissodactyla or Cetartiodactyla, being composed thus of several unrelated lineages. Taxonomic history Condylarthra always was a problematic group. When Condylarthra was first described by , Phenacodontidae was the type and only family therein. , however, raised Condylarthra to an order and included a wide range of diverse placentals with generalized dentitions and postcranial skeletons. More recent researchers (i.e. post-WW2) have been more restrictive; either including only a limited number of taxa, or proposing that the term should be abandoned altogether. Due to their primitive characteristics con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenacodonta
Phenacodontidae is an extinct family of large herbivorous mammals traditionally placed in the “ wastebasket taxon” Condylarthra, which may instead represent early-stage perissodactyls. They lived in the Paleocene and Eocene epochs (about 60–50 million years ago) and their fossil remains have been found in North America and Europe. Description These animals had a variety of body sizes, and could be as small as domestic cats ('' Tetraclaenodon'' and ''Ectocion'') and as large as sheep ('' Phenacodus''). The skull of phenacodontids is long and narrow, and equipped with a small braincase. The skeleton of phenacodontids show several primitive characteristics (the long and heavy tail for example) but also a number of advanced, Perissodactyla-like adaptations: Their long legs, for example, had five fingers, but the first finger showed a clear reduction, and in some forms (like ''Phenacodus'') the fifth finger was reduced as well. Some species had tapir-like adaptations s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenacodus
''Phenacodus'' (Greek: "deception" (phenax), "tooth' (odus)) is an extinct genus of mammals from the late Paleocene through middle Eocene, about 55 million years ago. It is one of the earliest and most primitive of the ungulates, typifying the family Phenacodontidae and the order Perissodactyla. Description The typical ''Phenacodus primaevus'' was a relatively small ungulate about long and weighed up to , of slight build, with straight limbs each terminating in five complete toes, and walking in the digitigrade fashion of the modern horse. The middle toe was the largest, and the weight of the body was mainly supported on this and the two adjoining digits, which appear to have been encased in hooves, foreshadowing the tridactyl type common in perissodactyls and certain extinct groups of ungulates. The skull was small, with proportionately minute brain; and the arched back, strong lumbar vertebrae, long and powerful tail, and comparatively feeble fore-quarters all proclaim kinsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
