Humankind's oldest known ancestor probably lived in fear of several large sabretooth cats that roamed the same ancient lakeside habitat in Africa.
Palaeontologists have identified two new sabretooth species among fossils unearthed at Toros Menalla in Chad.
In 2001, a team unearthed remains of a seven million-year-old human-like creature - or hominid - known as "Toumai" at the central African site.
Its discoverers argue that Toumai is the oldest hominid known to science ...
With our present data, we don't know what precisely the interactions were between a primate and a big carnivore. But probably these interactions were not so friendly," said Professor Vignaud.
He told BBC News: "Sabretooths hunted all mammals; bovids, equids... and primates. The interactions were also more 'psychological', exercising a stress on potential prey. We can't prove it but it's probably important because in that case, primates had to live near closed environments like gallery forest."
While ancient primates like Sahelanthropus tchadensis gave sabretooth cats a wide berth, they may also have depended on these big carnivores - and others - for their survival.
Sabretooths would have hunted large herbivorous mammals, and probably left enough meat on their kills for scavengers like the jackal-sized Hyaenictherium and perhaps even primates like Sahelanthropus.
Some researchers have proposed that Toumai is more closely related to chimpanzees or gorillas. Even if this were the case, the discovery would be of great significance, as virtually no fossil ancestors of these great apes are known from Africa.
via BBC News - Sabretooth cats threatened most ancient human ancestor.