Why do homo heidelbergensis and homo erectus both have supraorbital tori and lack chins?

Question

Why do homo heidelbergensis and homo erectus both have supraorbital tori and lack chins?

Answer 1

'cause they're actually british.

Answer 2

most homo genus lack chins because we diverged from the ape line which has a simian shelf.  it still wasn't really 'needed' till you got to homo sapiens.  i'm not sure about erectus, but i don't think they had chins.  the supraorbital tori is because their brains weren't yet high enough in the front to create the high rounded forehead we have today.      ...not the best explanation.  have a look at tolweb.org, archaeology.info, and nationalgeographic.com is always a good source.

Answer 3

Perhaps language ability has something to do with the supraorbital tori. I think they lacked chins simply because they were not yet evolved.  I think the main reason for a chin evolving is to protect the neck and Adam's apple.  Men have larger chins and perhaps this is to protect their larger Adam's apple that I believe is also involved in speech.

Answer 4

Because the latter was the ancestor of the former.