The Toumai is considered to be a male hominid as it has a thick brow ridge
and, judging from the size of the skull, was probably close to the size of a common chimpanzee, the researchers said.
Kappelman says the skull's heavy brow ridge
and sharply sloped forehead mark it as H.
Another telling sign appears on the Oase skull's forehead, which lacks a brow ridge
typical of Neandertals.
As in gorillas today, the heavy brow ridge
of Sahelanthropus worked with other skull elements to anchor powerful chewing muscles.
No one had predicted that elements of later skulls--in particular, a short, relatively flat face, pronounced brow ridge
, and small canine teeth--coexisted with a chimp-size brain in early hominids.
These include a prominent brow ridge
, a jutting face, large jaws, and a bony protrusion at the back of the head.
She notes, for instance, that the angle and size of the specimen's brain case and its moderate brow ridge
fall squarely between measurements of the same traits in the two established groups.
Round and swollen molar cusps and a brow ridge
that does not project from the face also link Ouranopithecus to early hominids, the French scientists say.
com/earth/story/20170214-your-face-is-probably-more-primitive-than-a-neanderthals) skull shapes that would have made it difficult for them to blend in today - large heads and faces, pronounced noses and brow ridges
and flat foreheads, to name a few.
The most prominent skeleton changes are the larger brain case, continued flattering of the face and the development of big brow ridges