This discovery could shed light on what the last common ancestor of all apes and humans might have been like, scientists added. So for years most researchers thought the ancestral ape must have tipped the scales as well. A fragmented skeleton dug out from a Spanish landfill may force scientists to redraw their theories on the ancestor of humans and all other apes. The animal is estimated to have weighed only 9 to 11 pounds, making it smaller than many modern monkeys.
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An ancient primate’s partial skeleton, discovered in northeastern Spain, is poised to downsize ape evolution in a big way.
The actual last common ancestor, which is theorized to have lived well before Laia roughly 17 million years ago, might have also been fairly easy going, although wary. “Alternatively, Pliobates might indicate that great apes evolved from gibbon-size ape ancestors”, said Almecija.
The discovery of Pliobates cataloniae fills a gap in the fossil record, giving scientists another piece of information about the evolution of great and small apes. Hylobatids, which includes gibbons, were considered red as dwarf great apes.
Paleontologists from Spain and the United States have discovered a new genus and species of small-bodied ape that lived about 11.6 million years ago, before the evolutionary split of humans/great apes (hominids) and gibbons (lesser apes). Among the bones was a well preserved skull, one of the best for a primate so old. Then they created a 3D reconstruction of the skull. Its elbow and wrist could rotate considerably to allow cautious, slow climbing, although its elbow lacked a ridge of bone that helps living apes stabilize their elbow joints while hanging by their arms, a feature that distinguishes living apes from other primates. Great apes including humans have these traits, but lesser apes do not.
This unusual mosaic of primitive and modern traits suggests that Pliobates didn’t launch itself from branch to branch like gibbon apes, but instead climbed relatively slowly in the trees, moving atop the branches carefully to eat fruit. Given its mix of characteristics, the authors suggest Pliobates was related to both lesser apes and greater apes. “I could imagine something with the face of a gibbon but moving much more slowly than a gibbon, like a slow loris atop the branches … eventually being able to suspend below them”, Alba says. This creature, depicted at right, may have been a surprisingly small ancestor of all modern apes.
“Pliobates suggests that small-bodied apes played a much more important role in the origin of extant apes than previously recognized”, Alba told Reuters, “and that their last common ancestor, in several respects, skull shape and body size, might have been more gibbon-like than previously thought”. That would mean it was the great apes, not the lesser ones, which diverged most from their ancestral petite body plan. “Maybe a few early ape ancestors were smaller than we thought”, said Almecija.
“You can’t ignore all the little guys”, he argues.
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They are calling this ancient primate “Pilobates cataloniae”, and they believe it could be the next missing link-the final common ancestor-between the hominids and the gibbons before the definitive evolutionary split.
