page_title: Femur
section_title: Other animals
hierarchical_section_title: Femur / Other animals
caption_attribution_description: English: From left to right: LB5990, LB8295, LB6070, LB6261d, LB6284, LB6261c, LB12961, LB6285b, LB6657, LB6071, LB6069. All are left femora except the two at far right. DNA analysis suggests all are from Euryapteryx except for LB6261c which was identified as Dinornis. Gridlines are at 10 mm intervals.
context_page_description: 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 and kneecap, forming the knee joint. By most measures the two femurs are the strongest bones of the body, and in humans,
  the longest.
context_section_description: In primitive tetrapods, the main points of muscle attachment along the femur are the internal trochanter and third trochanter, and a ridge along the ventral surface of the femoral shaft referred to as the adductor crest. The neck of the femur is generally minimal or absent in the most primitive forms, reflecting a simple attachment to the acetabulum. The greater trochanter was present in the extinct archosaurs, as well as in modern birds and mammals, being associated with the loss of the primitive sprawling gait. The lesser trochanter is a unique development of mammals, which lack both the internal and fourth trochanters. The adductor crest is also often absent in mammals or alternatively reduced to a series of creases along the surface of the bone.
  Some species of whales, snakes, and other non-walking vertebrates have vestigial femurs.
  One of the earliest known vertebrates to have a femur is the eusthenopteron, a prehistoric lobe-finned fish from the Late Devonian period.
  Structures analogous to the third trochanter are present in mammals, including some primates.
caption: Femora of Moa chicks.
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