Sunday, May 24, 2009

A Pliocene Hominin as Prey Item Gilbert, C., McGraw, W., & Delson, E. (2009). Brief communication: Plio-Pleistocene eagle predation on fossil cercopithecids from the Humpata Plateau, southern Angola American Journal of Physical Anthropology DOI: 10.1002/ajpa.21004

With all of the fanfare over human origins and primate evolution the last few days, I thought that it would be appropriate to take a quick look at an article recently published in The American Journal of Physical Anthropology. The article, “Plio-Pleistocene eagle predation on fossil cercopithecids from the Humpata Plateau, southern Angola,” discusses the taphonomic evidence for the taking of primates by predatory bird around the Pliocene/Pleistocene boundary at the renowned Taung site in South Africa – including the taking of a hominin.

NOTE: For those of you that may be familiar with the “Bird of Prey Hypothesis,” this article - to the best of my knowledge – represents the most recent support of Berger’s 1995 publication in The Journal of Human Evolution (Berger LR, Clarke RJ 1995).

The current article’s authors, Christopher Gilbert, W. Scott McGraw and Eric Delson, assessed the signatures of raptorial predation on cranial fragments recovered from the Taung site through direct comparison of the fossils with the cranial remains of extant primates from Tai National Park on the Ivory Coast.

The old world monkeys of Tai National Park, predominantly Chlorocebus sp, are heavily preyed on by Crowned Eagles (Stephanoaetus coronatus), which weigh about nine-pounds and have a wing span upwards three feet in length. Ninety-eight percent of the eagles’ diet is derived from mammals, and the majority of that is supplied by monkey flesh. As might be expected, the eagles are fearsome predators with talons that typically pierce the skull of their prey – thereby leaving a unique signature that can be readily identified by scientists.

Puncture and depression in monkey skull resulting from avian attack. Source: Berger

Of special interest in regards to human evolution is that in addition to the numerous skulls of Cercopithecoides shown to bear evidence of avian predation, a hominin fossil from the Taung site, a specimen of Australopithecus africanus estimated to be a child of about three, also displays the tell-tale punctures of predation from above.

Comparison of "Taung Child" (left) with monkey skull (right). Source Berger

Checkout the Discovery of Early Hominins site from Palomar College, San Marcos, California for additional info on hominin evolution, and the two Berger articles for more on the "Bird of Prey Hypothesis."

Berger, L. (2006). Brief communication: Predatory bird damage to the Taung type-skull ofAustralopithecus africanus Dart 1925 American Journal of Physical Anthropology, 131 (2), 166-168 DOI: 10.1002/ajpa.20415

Berger LR, Clarke RJ. (1995). Eagle involvement in accumulation of the Taung child fauna The Journal of Human Evolution (29), 275-279.

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