At the site of Kocabaş (southwest Turkey) a fragmentary cranium was recovered in 2002 from a travertine quarry alongside faunal remains. The skull has been assigned to Homo erectus and its morphology seems to be intermediate between the skulls from Dmanisi (Georgie, 1.8mya) and Zhoukoudian (China, 0.8mya). So far age determinations of the travertines at the site delivered conflicting results, with ESR estimates going back to 1.11 ± 0.11mya and thermoluminescence methods to around 500,000 years ago. However, for both methods we are dealing with the limits of their applicability. Therefore, a new multidisciplinary study, published with open access in Earth and Planetary Science Letters aimed to provide an absolute chronological framework for this important fossil.
The study, firstly, reassesses the geology of the site and its fauna, which includes southern elephant, Etruscan rhino, deer, very small elk, several horse species and giraffe. This fauna is generally characteristic of sites older than 1 million years.
Secondly, new comparative morphometric studies were conducted on the three refitting cranial fragments. These indicate a clear assignment to Homo erectus but more resemblance with the younger African and Chinese fossils that with the more archaic fossils from Dmanisi.
Thirdly, 165 samples for paleomagnetic analyses were collected across the stratigraphic sequence together with samples for cosmogenic nuclides measurement. The results of these studies indicate that a reverse polarity strongly dominates the Lower Conglomerates, which can be places between 1.78 and 1.63mya. The Upper Conglomerates, which contained the fossil, record a normal polarity and are compatible with an age between 1.1 and 1.3mya, in line with the characteristics of the fauna and the skull.
Overall, this paper not only testifies the old age of human occupation of the Anatolian peninsula, but also adds interesting new data to the timing and mechanisms behind the dispersal of Homo erectus out of Africa and across Eurasia.
Reference: Lebatard, A-E. 2014. Dating the Homo erectus bearing travertine from Kocabaş (Denizli, Turkey) at at least 1.1 Ma. Earth and Planetary Science Letters 390, 8–18. (Open Access)