Scientists have identified a new genus and species of ape that walked the Earth 11.6 million years ago, before hominids split from gibbons.

The ancient primate, dubbed Pliobates cataloniae, could be the key to reconstructing the last common ancestor of these two groups before the defining evolutionary split, George Washington University reported.

"This fossil discovery is providing a missing chapter to the beginning of ape and human history," said Sergio Almécija, assistant professor of anthropology in the Center for the Advanced Study of Human Paleobiology at GW's Columbian College of Arts and Sciences. "We used to think that small apes evolved from larger-bodied apes, but this new species tells us that small and large apes may have co-existed since hominoids originated. Alternatively, Pliobates might indicate that great apes evolved from gibbon-size ape ancestors."

The researchers made their fascinating findings after discovering a partial skeleton in a landfill in Barcelona in 2011. The remains consisted of 70 fossils pieces. The researchers believe the specimen was an adult female that weighed between nine and 11 pounds. The bones indicate the ancient ape feasted on soft fruits and swung through the tops of tree canopies.

The findings help to fill in a crucial gap in the fossil record, and reveal secrets of the evolution of both large and small apes.  A lack of  small ape and ancient gibbon fossils has researchers believing  great apes were present before small apes, but the discovery of Pliobates suggests small apes played a more important role in hominid evolution than was previously believed.

"These remains clearly belong to an ape, but they are so small," Almécija said. "Then we realized, maybe we are looking at this the wrong way. Maybe some early ape ancestors were smaller than we thought." 

The findings were published recently Science Magazine.