African hominid fed on unique hard diet

Berlin, July 1 (IANS) The two-million-year-old African hominid had a diet unlike all other known human ancestors, according to German researchers. Hominid is a primate of a family (Hominidae) that includes humans and their fossil ancestors.

The study, led by the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, and involving the University of Colorado-Boulder, US, indicated that Australopithecus sediba (A sediba), a short, gangly hominid that lived in South Africa -- ate harder foods than other early hominids, targeting trees, bushes and fruits.

Conversely, virtually all other ancient human ancestors tested from Africa -- including Paranthropus boisei, dubbed "Nutcracker Man" because of its massive jaws and teeth -- focused more on grasses and sedges, said Colorado doctoral student and study co-author Paul Sandberg.

The A. sediba diet was analyzed using a technique that involved zapping fossilized teeth with a laser, said Sandberg.

The laser frees telltale carbon from the enamel of teeth, allowing scientists to pinpoint the types of plants that were consumed and the environments in which the hominids lived, according to a institute statement.

The carbon signals from the teeth are split into two groups: C3 plants like trees, shrubs and bushes preferred by A. sediba, and C4 plants like grasses and sedges consumed by many other early hominids.

The teeth from the two A. sediba individuals analyzed in the study had carbon isotope values outside the range of all 81 previously tested hominids.

"The lack of any C4 evidence, and the evidence for the consumption of hard objects, are what make the inferred diet of these individuals compelling," said Sandberg.

"It is an important finding, because diet is one of the fundamental aspects of an animal, one that drives its behaviour and ecological niche. As environments change over time because of shifting climates, animals are generally forced to either move or to adapt to their new surroundings," added Sandberg.