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Obturator Externus Groove
The obturator externus groove is the groove on the posterior neck of the femur for the insertion of the obturator externus muscle, a muscle that is important during bipedal locomotion. This landmark is used as evidence of bipedal locomotion in the hominin The Hominini form a taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera ''Homo'' (humans) and '' Pan'' (chimpanzees and bonobos) and in standard usage excludes the genus ''Gorilla'' (gorillas). The t ...s. The fossil '' Orrorin tugenensis'' (6-7 mya) possesses the obturator externus groove, which suggests that it moved bipedally and could represent one of the earliest fossils with evidence of bipedal locomotion. Bones of the lower limb {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia (shinbone) and patella (kneecap), forming the knee joint. By most measures the two (left and right) femurs are the strongest bones of the body, and in humans, the largest and thickest. Structure The femur is the only bone in the upper leg. The two femurs converge medially toward the knees, where they articulate with the proximal ends of the tibiae. The angle of convergence of the femora is a major factor in determining the femoral-tibial angle. Human females have thicker pelvic bones, causing their femora to converge more than in males. In the condition ''genu valgum'' (knock knee) the femurs converge so much that the knees touch one another. The opposite extreme is ''genu varum'' (bow-leggedness). In the general populatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obturator Externus
The external obturator muscle, obturator externus muscle (; OE) is a flat, triangular muscle, which covers the outer surface of the anterior wall of the pelvis. It is sometimes considered part of the medial compartment of thigh, and sometimes considered part of the gluteal region. Structure It arises from the margin of bone immediately around the medial side of the obturator membrane and surrounding bone, viz., from the inferior pubic ramus, and the ramus of the ischium; it also arises from the medial two-thirds of the outer surface of the obturator membrane, and from the tendinous arch which completes the canal for the passage of the obturator vessels and nerves. The fibers springing from the pubic arch extend on to the inner surface of the bone, where they obtain a narrow origin between the margin of the foramen and the attachment of the obturator membrane. The fibers converge and pass posterolateral and upward, and end in a tendon which runs across the back of the neck of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bipedal
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' and ''pes'' 'foot'). Types of bipedal movement include walking, running, and hopping. Several groups of modern species are habitual bipeds whose normal method of locomotion is two-legged. In the Triassic period some groups of archosaurs (a group that includes crocodiles and dinosaurs) developed bipedalism; among the dinosaurs, all the early forms and many later groups were habitual or exclusive bipeds; the birds are members of a clade of exclusively bipedal dinosaurs, the theropods. Within mammals, habitual bipedalism has evolved multiple times, with the macropods, kangaroo rats and mice, springhare, hopping mice, pangolins and hominin apes ( australopithecines, including humans) as well as various other extinct groups evolving the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hominin
The Hominini form a taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera ''Homo'' (humans) and '' Pan'' (chimpanzees and bonobos) and in standard usage excludes the genus ''Gorilla'' (gorillas). The term was originally introduced by Camille Arambourg (1948). Arambourg combined the categories of ''Hominina'' and ''Simiina'' due to Gray (1825) into his new subtribe. Traditionally, chimpanzees, gorillas and orangutans were grouped together as pongids. Since Gray's classification, evidence has accumulated from genetic phylogeny confirming that humans, chimpanzees, and gorillas are more closely related to each other than to the orangutan. The former pongids were reassigned to the subfamily Hominidae ("great apes"), which already included humans, but the details of this reassignment remain contested; within Hominini, not every source excludes gorillas, and not every source includes chimpanzees. Humans are the only extant species in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orrorin Tugenensis
''Orrorin tugenensis'' is a postulated early species of Homininae, estimated at and discovered in 2000. It is not confirmed how ''Orrorin'' is related to modern humans. Its discovery was used to argue against the hypothesis that australopithecines are human ancestors, although this remains the most prevalent hypothesis of human evolution as of 2012. The name of genus ''Orrorin'' (plural ''Orroriek'') means "original man" in Tugen, and the name of the only classified species, ''O. tugenensis'', derives from Tugen Hills in Kenya, where the first fossil was found in 2000. As of 2007, 20 fossils of the species have been found. Fossils The 20 specimens found as of 2007 are believed to be from at least five individuals. They include: the posterior part of a mandible in two pieces; a symphysis and several isolated teeth; three fragments of femora; a partial humerus; a proximal phalanx; and a distal thumb phalanx. ''Orrorin'' had small teeth relative to its body size. Its dentition di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
