Careful analysis of microscopic abrasions on the teeth of early human “cousins” by resesarchers at Johns Hopkins, University of Arkansas, Cambridge University and Stony Brook University show that although equipped with thick enamel, large jaws and powerful chewing muscles, this ancient species may not have eaten the nuts, seeds or roots their anatomy suggests. Instead, the tooth wear suggests a more general diet, as reported in next week’s Public Library of Science One.
“For so many years we’ve operated under the assumption that the shape of something’s teeth, jaws and skull tells us what they habitually ate,” says Mark Teaford, Ph.D., a professor of anatomy at Hopkins’ Center for Functional Anatomy and Evolution. “But it seems like we had the wrong idea-just because they’re capable of eating hard foods doesn’t mean that they did-it really makes us rethink some of our basic assumptions.”
Which is interesting. Also, more here. I suppose the shape of the jaw and skull and what not could still be an adaptation for the ability to eat hard (less desirable) foods, just not on a regular basis. I.e., selected for in times of scarcity.
UPDATE: See also this on Neanderthal diet.