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Phenacodontid
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 suggest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ungulate
Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, camels, sheep, deer, and hippopotamuses. Cetaceans such as whales, dolphins, and porpoises are also classified as even-toed ungulates, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes to support their body weight while standing or moving. The term means, roughly, "being hoofed" or "hoofed animal". As a descriptive term, "ungulate" normally excludes cetaceans as they do not possess most of the typical morphological characteristics of other ungulates, but recent discoveries indicate that they were also descended from early artiodactyls. Ungulates are typically herbivorous and many employ specialized gut bacteria to allow them to digest cellulose. Some modern species, such as pigs, are omnivorous, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odd-toed Ungulate
Odd-toed ungulates, mammals which constitute the taxonomic order Perissodactyla (, ), are animals—ungulates—who have reduced the weight-bearing toes to three (rhinoceroses and tapirs, with tapirs still using four toes on the front legs) or one (equines, third toe) of the five original toes. The non-weight-bearing toes are either present, absent, vestigial, or positioned posteriorly. By contrast, the even-toed ungulates bear most of their weight equally on four or two (an even number) of the five toes: their third and fourth toes. Another difference between the two is that odd-toed ungulates digest plant cellulose in their intestines rather than in one or more stomach chambers as even-toed ungulates, with the exception of Suina, do. The order includes about 17 species divided into three families: Equidae (horses, asses, and zebras), Rhinocerotidae (rhinoceroses), and Tapiridae (tapirs). Despite their very different appearances, they were recognized as related families in ... [...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 condylar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wastebasket Taxon
Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined by either their designated members' often superficial similarity to each other, or their ''lack'' of one or more distinct character states or by their ''not'' belonging to one or more other taxa. Wastebasket taxa are by definition either paraphyletic or polyphyletic, and are therefore not considered valid taxa under strict cladistic rules of taxonomy. The name of a wastebasket taxon may in some cases be retained as the designation of an evolutionary grade, however. The term was coined in a 1985 essay by Steven Jay Gould. Examples There are many examples of paraphyletic groups, but true "wastebasket" taxa are those that are known not to, and perhaps not intended to, represent natural groups, but are nevertheless used as convenient groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Almogaver
''Almogaver'' is an extinct possible odd-toed ungulate genus in the family Phenacodontidae. It was a ground-dwelling herbivore. It is known from the Tremp Basin in Spain, and some authorities consider it synonymous with ''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 fa ...''.Cuesta Ruiz-Colmenares, Eocene Mammals from Iberian Peninsula. 1997 References Condylarths Paleocene mammals of Europe Paleogene Spain Fossils of Spain Fossil taxa described in 1954 Nomina dubia Prehistoric placental genera {{paleo-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthaspidotherium
''Orthaspidotherium'' was a European Paleocene genus of early herbivorous mammals of the family Pleuraspidotheriidae. It was included in the family Meniscotheriidae by Teilhard de Chardin Pierre Teilhard de Chardin ( (); 1 May 1881 – 10 April 1955) was a French Jesuit priest, scientist, paleontologist, theologian, philosopher and teacher. He was Darwinian in outlook and the author of several influential theological and philo ... in 1921-1922 and was subsequently separated into the family Pleuraspidotheriidae, before being placed in the family Phenacodontidae. The first complete skull of ''O. edwardsi'' was described in 2010, and the same paper once again places it in Pleuraspidotheriidae. A 2017 study further reiterates this view. References Condylarths Prehistoric placental genera Paleocene mammals of Europe {{paleo-mammal-stub ... [...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 kinship ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyracoids
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, they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectocion Ralstonensis Granger 1
''Ectocion'' (sometimes ''Ectocyon'') is an extinct genus of placental mammals of the family Phenacodontidae. The genus was earlier classified as ''Gidleyina'' (Simpson 1935) and ''Prosthecion'' (Patterson and West 1973). Retrieved May 2013. Paleocene specimens of these hoofed, ground-dwelling herbivores have been found in Canada (Alberta, Saskatchewan) and the United States (Colorado, Montana, North Dakota, and Wyoming). Eocene specimens have been found in Mexico and the United States (Colorado, Mississippi, Wyoming). One of the dramatic effects of the Paleocene–Eocene Thermal Maximum The Paleocene–Eocene thermal maximum (PETM), alternatively (ETM1), and formerly known as the "Initial Eocene" or "", was a time period with a more than 5–8 °C global average temperature rise across the event. This climate event o ... (PETM) was some animals evolving smaller bodies. Fossilized ''Ectocion'' jaw bones show that this genus was smaller during (''E. parvus'', 55. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by Chicxulub impact, an asteroid impact and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. In the Pal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenacodontinae
Phenacodontinae was a subfamily of small herbivorous mammals that were part of the Phenacodontidae family. Genera The subfamily contains the following genera: * †''Almogaver'' * †''Copecion'' * †'' Lophocion'' * †'' Eodesmatodon'' * †''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 fa ...'' References Condylarths Mammal subfamilies {{paleo-oddtoedungulate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraclaenodon
''Tetraclaenodon'' was a genus of small and early ungulate mammals that was part of the Phenacodontidae Phenacodontidae is an extinct family (biology), family of large herbivorous mammals traditionally placed in the “wastebasket taxon” Condylarthra, which may instead represent early-stage Perissodactyla, perissodactyls. They lived in the Paleo ... family. References Condylarths Prehistoric mammal genera Fossil taxa described in 1892 Paleocene mammals of North America {{paleo-oddtoedungulate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
