A Spanish team has uncovered an exceptionally complete 13-million-year-old fossil that it says is closely related to the earliest members of the great ape family--the large-bodied, long-lived, intelligent clan that includes chimpanzees, orangutans, and humans. The new find from Barcelona, reported in this week's issue of Science, is the most ancient ape to show the upright posture, muzzleless face, and other key traits seen in all living great apes, including people.
Over the past few decades, paleoanthropologists tracing the human lineage back through time have uncovered a series of increasingly apelike ancestors that date from 4 million to 6 million years ago. Even further back, however, the ancestors of humans and our ape cousins remain mysterious, hidden by a patchy fossil record.
In December 2002, members of a team led by Salvador Moyà-Solà, a paleoanthropologist at the Institut de Paleontologia M. Crusafont in Barcelona, found a canine tooth and an apelike face at a new site near Barcelona. In 2003, the team recovered the ribs, wrist, hands, and vertebrae of a single male individual within an area of about 25 square meters.The resulting creature, named Pierolapithecus catalaunicus after the nearby village of Els Hostalets de Pierola in Catalonia, reveals a mix of apelike and monkeylike traits. Compared to earlier Miocene apes, for example, the face has a much-reduced muzzle resembling the living great apes. The wide and shallow rib cage and details of the vertebrae show that the roughly 30-kilogram creature stood upright, as great apes do. But not on the ground: Pierolapithecus was a tree dweller, eating fruits and vegetation in a tropical forest. Although it has flexible wrists like those of tree-swinging apes and bipedal humans, it retains the relatively small hands and straight fingers of monkeys, implying that, like them, it sometimes walked on all fours on tree limbs. "From these fossils we have, for the first time in the Middle Miocene, the key diagnostic features of the living apes," together with a large set of primitive monkeylike features, says Moyà-Solà.
Paleoanthropologist Carol V. Ward of the University of Missouri, Columbia, calls Pierolapithecus an "amazing fossil." But not everyone agrees with the team's interpretations. "It's a marvelous find, a dream come true," says paleoanthropologist Steven Ward (no relation to Carol) of the Northeastern Ohio Universities College of Medicine in Rootstown. "But the true phylogeny of the great apes is still open to question and will probably not be resolved by this wonderful specimen."