Palaeontology: Primitive hominins outside Africa

Scientists have uncovered the remains of three adults and one adolescent individual, 1.77 million years old, from the Plio-Pleistocene sight of Dmanisi, Georgia. The remains — early evidence of the genus Homo outside Africa — are remarkably well preserved and the postcranial material displays a mixture of primitive and more advanced features. David Lordkipanidze and colleagues analyse the fossils and discuss their evolutionary context in this week’s Nature.

Over the last few decades the site of Dmanisi has yielded a rich fossil and archaeological record — animal remains, primitive tools, and fossil hominin skulls and jaws have all been unearthed. Scientists’ knowledge of the cranio-facial morphology of these early species is reasonably well developed, but there has been little ‘postcranial’ evidence from a complete skeleton.

The authors now present a partial skeleton of an adolescent individual associated with a skull, and the postcranial remains of three adults. The hominins have relatively small cranial capacities and primitive australopith-like upper limbs. However, their spines and lower limbs seem essentially modern, indicating the capability for long-distance travel.

The authors conclude that the Dmanisi hominins — the first hominin species currently known from outside Africa — did not display a full set of advanced locomotor features apparent in African Homo erectus and later hominins. The fossils therefore fill significant gaps in our knowledge of a critical period in human evolution — the transition from autralopith-like species to more modern human-like morphologies.