Research in 2008 on two teeth from Nutcracker Man in Tanzania also indicated the creatures ate a diet of grasses and perhaps sedges. But with teeth from 22 individuals, the new study shows the species was eating grass and other C4 plants over a much longer time period (from 1.4 million to 1.9 million years ago) and bigger geographic area (a 500-mile-wide swath of East Africa) than was known before.
"Wherever we find this creature, it is predominantly eating tropical grasses or perhaps sedges, which include papyrus," Cerling says.
Rethinking the Diets of Early Human Ancestors and Relatives
The new study of Nutcracker Man may provoke a major change in how we view the diets of other early humans and human relatives.
"Much of the previous work has been on the size and shape of the teeth, along with microwear analysis," Cerling says. "Our results [on Paranthropus boisei] are completely different than the conclusions based on 50-plus years of research along those lines. It stands to reason that other conclusions about other species also will require revision. P. boisei greatly extends the range of potential diets for early human lineages."
Specifically, scientists have believed human ancestors in the genus Australopithecus which gave rise to now-extinct Paranthropus and to Homo or early humans also had head and tooth features suggesting they ate hard objects like nuts.
Cerling says carbon isotope ratios in australopiths' teeth now should be studied, since the Paranthropus findings bring in to question interpretations that are made without isotopic information on diets.
"The high proportion of C4 vegetation in the diet of Paranthropus boisei makes it different from any other hominin to date, even its closest relative, Paranthropus robustus fr
|Contact: Lee Siegel|
University of Utah