A new face to an old name: Recent discovery of a cranium of the earliest Australopithecus in Ethiopia.
Dr. Yohannes Haile-Selassie
Curator of Physical Anthropology, Cleveland Museum of Natural History
Adjunct Professor, Case Western Reserve University
Woranso-Mille, a paleoanthropological site located in the Afar region of Ethiopia, has become one of the most important sites to understand the evolutionary history of early hominins during the mid-Pliocene. The geological sequence at this site (~150 meters-thick) samples almost one and a half million years, between >4.3 and <3.0 million years ago (Ma). It is the only site thus far that has provided incontrovertible fossil evidence showing that there were multiple related hominin species co-existing in close geographic proximity during the mid-Pliocene (3.5 – 3.3 Ma). Recently, a 3.8-million-year-old almost complete hominin cranium was discovered at the site and it was assigned to A. anamensis - the earliest known species of the genus Australopithecus – dated to 4.2 – 3.9 Ma. In addition to revealing the face of A. anamensis for the first time, the new cranium also challenged the long-held hypothesis of direct, linear evolution from A. anamensis to Lucy’s species, A. afarensis, and added about 100kyr to the younger end of the A. anamensis time range. A new, more complex scenario for the origins of the human lineage is discussed in light of these latest finds and analyses.