{"id":269700,"date":"2026-01-06T05:18:09","date_gmt":"2026-01-06T05:18:09","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/269700\/"},"modified":"2026-01-06T05:18:09","modified_gmt":"2026-01-06T05:18:09","slug":"7-million-year-old-sahelanthropus-fossils-bolster-case-for-earliest-upright-walking","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/269700\/","title":{"rendered":"7-Million-Year-Old Sahelanthropus Fossils Bolster Case for Earliest Upright Walking"},"content":{"rendered":"

For more than two decades, Sahelanthropus tchadensis<\/a> \u2014 a very early (6.7 to 7.2 million years old) hominin species discovered<\/a> in Chad in 2001 \u2014 has hovered at the center of a contentious question: did one of humanity\u2019s earliest relatives walk upright? New research led by New York University paleoanthropologists adds the strongest evidence yet that it did. Their findings suggest that Sahelanthropus tchadensis was an African ape-like early hominin with the earliest known adaptations to terrestrial bipedalism.<\/strong><\/p>\n

\"Reconstruction<\/a><\/p>\n

Reconstruction of Sahelanthropus tchadensis. Image credit: University of Silesia.<\/p>\n

\u201cSahelanthropus tchadensis was essentially a bipedal ape that possessed a chimpanzee-sized brain and likely spent a significant portion of its time in trees, foraging and seeking safety,\u201d said New York University\u2019s Dr. Scott Williams<\/a>.<\/p>\n

\u201cDespite its superficial appearance, Sahelanthropus tchadensis was adapted to using bipedal posture and movement on the ground.\u201d<\/p>\n

In the study, Dr. Williams and his colleagues focused on a femur and two partial forearm bones of Sahelanthropus tchadensis recovered at the site of Toros-Menalla in Chad.<\/p>\n

While earlier work argued that the bones were too apelike to support upright walking, their new analysis combines 3D shape modeling with anatomical traits linked specifically to human-style locomotion.<\/p>\n

\u201cTogether, these features suggest hominin-like hip and knee function in Sahelanthropus tchadensis and may represent some of the earliest adaptations to bipedalism in the hominin lineage,\u201d they said.<\/p>\n

The researchers found that although the external shape of the limb bones most closely resembles that of chimpanzees, their proportions tell a different story.<\/p>\n

The relationship between arm and leg length is described as more hominin-like, falling between modern bonobos and early members of the human lineage.<\/p>\n

Most striking, they identified a small bony structure on the femur \u2014 a femoral tubercle \u2014 that serves as the attachment point for the iliofemoral ligament, a key stabilizer of the human hip.<\/p>\n

According to the team, this feature has thus far only been identified in hominins.<\/p>\n

The femur also shows pronounced internal twisting, known as antetorsion<\/a> (medial torsion of the femoral shaft), a trait associated with bringing the knees beneath the body\u2019s center of mass during walking.<\/p>\n

This torsion falls exclusively with hominins when compared with both living apes and extinct Miocene species.<\/p>\n

Taken together, the findings challenge long-standing assumptions about how and when upright walking evolved.<\/p>\n

Rather than emerging suddenly, the scientists argue, bipedalism developed gradually.<\/p>\n

\u201cWe consider the evolution of bipedalism to be a process rather than an event,\u201d they said.<\/p>\n

\u201cSahelanthropus tchadensis may represent an early form of habitual, but not obligate, bipedalism.\u201d<\/p>\n

\u201cIn addition to terrestrial bipedalism, Sahelanthropus tchadensis likely engaged in a diverse set of arboreal positional behaviors not limited to vertical climbing, below-branch forelimb suspension, arboreal quadrupedalism and bipedalism, and various forms of climbing.\u201d<\/p>\n

The authors interpret the fossil as evidence that early hominins evolved from a \u2018Pan-like Miocene ape ancestor,\u2019 reinforcing models that place chimpanzee-like creatures near the root of the human family tree.<\/p>\n

\u201cOur analysis of these fossils offers direct evident that Sahelanthropus tchadensis could walk on two legs, demonstrating that bipedalism evolved early in our lineage and from an ancestor that looked most similar to today\u2019s chimpanzees and bonobos,\u201d Dr. Williams said.<\/p>\n

The study<\/a> was published this month in the journal Science Advances.<\/p>\n

_____<\/p>\n

Scott A. Williams et al. 2026. Earliest evidence of hominin bipedalism in Sahelanthropus tchadensis. Science Advances 12 (1); doi: 10.1126\/sciadv.adv0130<\/p>\n","protected":false},"excerpt":{"rendered":"For more than two decades, Sahelanthropus tchadensis \u2014 a very early (6.7 to 7.2 million years old) hominin…\n","protected":false},"author":2,"featured_media":269701,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77],"tags":[4204,137695,80839,137696,121816,45911,18,137697,108261,4696,13645,19,17,30207,46510,137698,137699,133,137700,137701,544],"class_list":{"0":"post-269700","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-africa","9":"tag-antetorsion","10":"tag-bipedalism","11":"tag-bonobo","12":"tag-chad","13":"tag-chimpanzee","14":"tag-eire","15":"tag-femur","16":"tag-forearm","17":"tag-fossil","18":"tag-hominin","19":"tag-ie","20":"tag-ireland","21":"tag-locomotion","22":"tag-miocene","23":"tag-sahelanthropus","24":"tag-sahelanthropus-tchadensis","25":"tag-science","26":"tag-toros-menalla","27":"tag-ulna","28":"tag-walking"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/115846466985266818","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/269700","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=269700"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/269700\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/269701"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=269700"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=269700"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=269700"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}