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Azibiidae
Azibiidae is an extinct family of fossil primate from the late early or early middle Eocene from the Glib Zegdou Formation in the Gour Lazib area of Algeria. They are thought to be related to the living toothcombed primates, the lemurs and lorisoids (known as strepsirrhines), although paleoanthropologists such as Marc Godinot have argued that they may be early simians (monkeys and apes). It includes the genera '' Azibius'' and '' Algeripithecus'', the latter of which was originally considered the oldest known simian, not a strepsirrhine. Originally described as a type of plesiadapiform (an extinct group of arboreal mammals considered to be a sister group to the primate clade), its fragmentary remains have been interpreted as a hyopsodontid (a type of extinct condylarth), an adapid (an extinct type of adapiform primate from Europe), and a macroscelidid (elephant shrews). Less fragmentary remains discovered between 2003 and 2009 demonstrated a close relationship betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algeripithecus
''Algeripithecus'' is an extinct genus of early fossil primate, weighing approximately . Fossils have been found in Algeria dating from 50 to 46 million years ago. It was once commonly thought to be one of the oldest simian primates (a group that includes monkeys and apes), and was crucial to the hypothesis that simians originated in Africa. Research on more complete specimens suggest it was instead a strepsirrhine primate, more closely related to living lemurs and lorisoids. However, this is still disputed. Discovery Fragmentary fossils were first found in the Glib Formation at the Glib Zegdou locality in Algeria and dated to the Early to Middle Eocene, 50 to 46 million years ago. The holotype was an upper left molar (M2). Evolutionary history and taxonomy First described in the journal ''Nature'' by Marc Godinot and Mohamed Mahboubi in 1992, ''Algeripithecus'' was once widely considered one of the oldest known fossil simian primates, giving weight to the African origin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strepsirrhini
Strepsirrhini or Strepsirhini (; ) is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia. Collectively they are referred to as strepsirrhines. Also belonging to the suborder are the extinct adapiform primates which thrived during the Eocene in Europe, North America, and Asia, but disappeared from most of the Northern Hemisphere as the climate cooled. Adapiforms are sometimes referred to as being "lemur-like", although the diversity of both lemurs and adapiforms does not support this comparison. Strepsirrhines are defined by their "wet" (moist) rhinarium (the tip of the snout) – hence the colloquial but inaccurate term "wet-nosed" – similar to the rhinaria of canines and felines. They also have a smaller brain than comparably sized simians, large olfactory lobes for smell, a vomeronasal organ to detect pheromones, and a bic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossil Primates
This is a list of fossil primates—extinct primates for which a fossil record exists. Primates are generally thought to have evolved from a small, unspecialized mammal, which probably fed on insects and fruits. However, the precise source of the primates remains controversial and even their arboreal origin has recently been questioned. As it has been suggested, many other mammal orders are arboreal too, but they have not developed the same characteristics as primates. Nowadays, some well known genera, such as ''Purgatorius'' and ''Plesiadapis'', thought to be the most ancient primates for a long time, are not usually considered as such by recent authors, who tend to include them in the new order Plesiadapiformes, within superorder Euarchontoglires. Some, to avoid confusions, employ the unranked term Euprimates, which excludes Plesiadapiformes. That denomination is not used here. There is an academic debate on the time the first primates appeared. One of the earliest probable prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adapiformes
Adapiformes is a group of early primates. Adapiforms radiated throughout much of the northern continental mass (now Europe, Asia and North America), reaching as far south as northern Africa and tropical Asia. They existed from the Eocene to the Miocene epoch. Some adapiforms resembled living lemurs. Adapiforms are known from the fossil record only, and it is unclear whether they form a monophyletic or paraphyletic group. When assumed to be a clade, they are usually grouped under the "wet-nosed" taxon Strepsirrhini, which would make them more closely related to the lemurs and less so to the "dry-nosed" Haplorhini taxon that includes monkeys and apes.Callum Ross, Richard F. Kay, ''Anthropoid origins: new visions'', Springer, 2004, , p. 100 In 2009, Franzen and colleagues placed the newly described genus ''Darwinius'' in the "Adapoidea group of early primates representative of early haplorhine diversification" so that, according to these authors, the adapiforms would not be withi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toothcomb
A toothcomb (also tooth comb or dental comb) is a dental structure found in some mammals, comprising a group of front teeth arranged in a manner that facilitates grooming, similar to a hair comb. The toothcomb occurs in lemuriform primates (which includes lemurs and lorisoids), treeshrews, colugos, hyraxes, and some African antelopes. The structures evolved independently in different types of mammals through convergent evolution and varies both in dental composition and structure. In most mammals the comb is formed by a group of teeth with fine spaces between them. The toothcombs in most mammals include incisors only, while in lemuriform primates they include incisors and canine teeth that tilt forward at the front of the lower jaw, followed by a canine-shaped first premolar. The toothcombs of colugos and hyraxes take a different form with the individual incisors being serrated, providing multiple tines per tooth. The toothcomb is usually used for grooming. While licki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condylarth
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] |
Adapidae
Adapidae is a family of extinct primates that primarily radiated during the Eocene epoch between about 55 and 34 million years ago. Adapid systematics and evolutionary relationships are controversial, but there is fairly good evidence from the postcranial skeleton (everything but the skull, or cranium) that adapids were stem strepsirrhines (members of the group including the living lemurs, lorises, and bushbabies). In particular, the anatomy of the adapid wrist and ankle (e.g., position of the groove for the flexor fibularis tendon on the talus, the presence of a sloping talo-fibular facet) show derived similarities with those of living strepsirrhines. However, adapids lacked many of the anatomical specializations characteristic of living strepsirrhines, such as a toothcomb A toothcomb (also tooth comb or dental comb) is a dental structure found in some mammals, comprising a group of front teeth arranged in a manner that facilitates grooming, similar to a hair comb. The to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elephant Shrew
Elephant shrews, also called jumping shrews or sengis, are small insectivorous mammals native to Africa, belonging to the family Macroscelididae, in the order Macroscelidea. Their traditional common English name "elephant shrew" comes from a perceived resemblance between their long noses and the trunk of an elephant, and their superficial similarity with shrews (family Soricidae) in the order Eulipotyphla. However, phylogenetic analysis has revealed that elephant shrews are not properly classified with true shrews, but are in fact more closely related to elephants than to shrews. In 1997, the biologist Jonathan Kingdon proposed that they instead be called "sengis" (singular ''sengi''), a term derived from the Bantu languages of Africa, and in 1998, they were classified into the new clade Afrotheria. They are widely distributed across the southern part of Africa, and although common nowhere, can be found in almost any type of habitat, from the Namib Desert to boulder-strewn outc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Talus Bone
The talus (; Latin for ankle or ankle bone), talus bone, astragalus (), or ankle bone is one of the group of foot bones known as the tarsus. The tarsus forms the lower part of the ankle joint. It transmits the entire weight of the body from the lower legs to the foot.Platzer (2004), p 216 The talus has joints with the two bones of the lower leg, the tibia and thinner fibula. These leg bones have two prominences (the lateral and medial malleoli) that articulate with the talus. At the foot end, within the tarsus, the talus articulates with the calcaneus (heel bone) below, and with the curved navicular bone in front; together, these foot articulations form the ball-and-socket-shaped talocalcaneonavicular joint. The talus is the second largest of the tarsal bones; it is also one of the bones in the human body with the highest percentage of its surface area covered by articular cartilage. It is also unusual in that it has a retrograde blood supply, i.e. arterial blood enters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
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] |
Evolutionary History Of Lemurs
Lemurs, primates belonging to the suborder Strepsirrhini which branched off from other primates less than 63 million years ago, evolved on the island of Madagascar, for at least 40 million years. They share some traits with the most basal primates, and thus are often confused as being ancestral to modern monkeys, apes, and humans. Instead, they merely resemble ancestral primates. Lemurs are thought to have evolved during the Eocene or earlier, sharing a closest common ancestor with lorises, pottos, and galagos ( lorisoids). Fossils from Africa and some tests of nuclear DNA suggest that lemurs made their way to Madagascar between 40 and 52 mya. Other mitochondrial and nuclear DNA sequence comparisons offer an alternative date range of 62 to 65 mya. An ancestral lemur population is thought to have inadvertently rafted to the island on a floating mat of vegetation, although hypotheses for land bridges and island hopping have also been proposed. The timing and nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyopsodontidae
Hyopsodontidae is an extinct family of primitive mammals from the order Condylarthra, living from the Paleocene to the Eocene in North America and Eurasia. Condylarthra is now thought to be a wastebasket taxon; hyopsodontids have occasionally been speculated to be related to Afrotheria, but the most recent consensus is that they are related to Perissodactyla. Analysis of the inner ear shows shared characteristics with the Equoidea (horses and paleotheres); they may be a basal ungulate group near to perissodactyls. They were generally small omnivores An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ..., like many early mammals. The most common genus is '' Hyopsodus''. Members of the family were small by modern standards, ranging in size from a small rat to a raccoon. The hyopsod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
