Publication Date:
2009-10-08
Description:
The femur and pelvis of Ardipithecus ramidus have characters indicative of both upright bipedal walking and movement in trees. Consequently, bipedality in Ar. ramidus was more primitive than in later Australopithecus. Compared with monkeys and Early Miocene apes such as Proconsul, the ilium in Ar. ramidus is mediolaterally expanded, and its sacroiliac joint is located more posteriorly. These changes are shared with some Middle and Late Miocene apes as well as with African apes and later hominids. However, in contrast to extant apes, bipedality in Ar. ramidus was facilitated by craniocaudal shortening of the ilium and enhanced lordotic recurvature of the lower spine. Given the predominant absence of derived traits in other skeletal regions of Ar. ramidus, including the forelimb, these adaptations were probably acquired shortly after divergence from our last common ancestor with chimpanzees. They therefore bear little or no functional relationship to the highly derived suspension, vertical climbing, knuckle-walking, and facultative bipedality of extant African apes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lovejoy, C Owen -- Suwa, Gen -- Spurlock, Linda -- Asfaw, Berhane -- White, Tim D -- New York, N.Y. -- Science. 2009 Oct 2;326(5949):71e1-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Anthropology, School of Biomedical Sciences, Kent State University, Kent, OH 44242-0001, USA. olovejoy@aol.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19810197" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
*Biological Evolution
;
Ethiopia
;
Femur/*anatomy & histology
;
*Fossils
;
Hominidae/*anatomy & histology/*physiology
;
Ilium/anatomy & histology
;
Ischium/anatomy & histology
;
Locomotion
;
Pelvic Bones/*anatomy & histology
;
Pelvis/anatomy & histology
;
Posture
;
Pubic Bone/anatomy & histology
;
Ribs/anatomy & histology
;
Spine/anatomy & histology
;
Thorax/anatomy & histology
;
*Walking
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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