Dimanisi is an ancient castle ruin in the Republic of Georgia in the Caucasus. Underneath it, in a cave that was apparently the lair of saber-toothed cats, are the incomparably more ancient bones of 4- to 5-foot tall creatures, probably resembling chimpanzees more than humans, from whom the greater part of earth’s human population descends. These unfortunate members of the species Homo erectus apparently became part of the cats’ diet.
The bones are a trove for paleoanthropologists because the diminutive hominids, which walked upright, are roughly coeval with the earliest such remains unearthed at Tanzania’s Olduvai Gorge and other sites in Africa, dating to some 1.8 million years ago. Dimanisi shows that the colonization of the world beyond mankind’s African primate nursery began earlier than many researchers had thought.
Five skulls recovered during 20 years of digging at the site include one that is remarkably complete. The creatures, which probably lived several hundred years apart, had small braincases like their Olduvai cousins, but the skulls show many anatomical details in common with their Homo sapiens descendants.
Importantly, the skulls suggest that the specimens belong to one species, erectus, challenging the notion prominent among those who study human origins that the exodus out of Africa was accomplished by several Homo species.
Not that there hasn’t been plenty of time: 1.8 million years is a staggering span — more than a thousand times greater than the period since the most recent glaciation, which subsumes the entire period of human civilization.
The takeaway? For almost all of those 1.8 million years, until very recently, we’ve been cat food.