What did early hominids eat?

Paranthropus boisei, dubbed "Nutcracker Man." may not have cracked nuts after all.

ScienceDaily — New assessments by researchers using the latest high-tech tools to study the diets of early hominids are challenging long-held assumptions about what our ancestors ate, says a study by the University of Colorado Boulder and the University of Arkansas.

By analyzing microscopic pits and scratches on hominid teeth, as well as stable isotopes of carbon found in teeth, researchers are getting a very different picture of the diet habitats of early hominids than that painted by the physical structure of the skull, jawbones and teeth. While some early hominids sported powerful jaws and large molars -- including Paranthropus boisei, dubbed "Nutcracker Man" -- they may have cracked nuts rarely if at all, said CU-Boulder anthropology Professor Matt Sponheimer, study co-author.

Such findings are forcing anthropologists to rethink long-held assumptions about early hominids, aided by technological tools that were unknown just a few years ago. A paper on the subject by Sponheimer and co-author Peter Ungar, a distinguished professor at the University of Arkansas, was published in the Oct. 14 issue of Science.

Earlier this year, Sponheimer and his colleagues showed Paranthropus boisei was essentially feeding on grasses and sedges rather than soft fruits preferred by chimpanzees. "We can now be sure that Paranthropus boisei ate foods that no self-respecting chimpanzee would stomach in quantity," said Sponheimer. "It is also clear that our previous notions of this group's diet were grossly oversimplified at best, and absolutely backward at worst."

"The morphology tells you what a hominid may have eaten," said Ungar. But it does not necessarily reveal what the animal was actually dining on, he said.