Science, Tech, Math › Animals & Nature Propliopithecus (Aegyptopithecus) Profile Share Flipboard Email Print Dan Wright/Getty Images Animals & Nature Dinosaurs Prehistoric Mammals Basics Paleontologists Carnivores Dinosaurs & Birds Herbivores Marine Reptiles Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Forestry Evolution View More By Bob Strauss Science Writer B.S., Cornell University Bob Strauss is a science writer and the author of several books, including "The Big Book of What, How and Why" and "A Field Guide to the Dinosaurs of North America." our editorial process Bob Strauss Updated March 04, 2019 Name: Propliopithecus (Greek for "before Pliopithecus"); pronounced PRO-ply-oh-pith-ECK-us; also known as Aegyptopithecus Habitat: Woodlands of northern Africa Historical Epoch: Middle Oligocene (30-25 million years ago) Size and Weight: About two feet long and 10 pounds Diet: Probably omnivorous Distinguishing Characteristics: Small size; sexual dimorphism; flat face with forward-facing eyes About Propliopithecus (Aegyptopithecus) As you can tell from its nearly unpronounceable name, Propliopithecus was named in reference to the much later Pliopithecus; this middle Oligocene primate may also have been the same animal as Aegyptopithecus, which provisionally continues to occupy its own genus. The importance of Propliopithecus is that it occupied a place on the primate evolutionary tree very near to the ancient split between "old world" (i.e., African and Eurasian) apes and monkeys, and may well have been the earliest true ape. Still, Propliopithecus was no chest-pounding behemoth; this ten-pound primate looked like a small gibbon, ran on all fours like a macaque, and possessed a relatively flat face with forward-facing eyes, an adumbration of its human-like hominid descendants that evolved millions of years later. How smart was Propliopithecus? One shouldn't have too ambitious hopes for a primate that lived 25 million years ago, and in fact, an initial brain-size estimate of 30 square centimeters has since been reduced to 22 square centimeters, on the basis of more complete fossil evidence. In the course of analyzing skull samples, the same research team that produced the latter estimate also concluded that Propliopithecus was sexually dimorphic (males were about one and one-half times as big as females), and we can infer that this primate scrambled between the branches of trees—that is, it had not yet learned to walk on solid ground.