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.
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.
As you will see from the attached photo, he bears strong facial and cranial similarities to the original Neanderthal man - with prominent brow ridge
and low, sloping forehead.
Sexually dimorphic features in male faces include a broad jaw, broad forehead, and more pronounced brow ridge
, while a sexually dimorphic female face has a more tapered chin, larger lips, and a narrower forehead.
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.
Although her skull had the prominent brow ridges
, low forehead, and protruding lower face that would have made her unusual-looking to modern eyes, the structure and size of the rest of her body was very similar to ours.