J. van der Made

A new early Pleistocene hominin mandible from Atapuerca-TD6, Spain

We present the description of a new mandibular specimen, ATD6-113, recovered in 2006 from the TD6 level of the Gran Dolina cave site in Sierra de Atapuerca, northern Spain. A detailed study of the lithostratigraphy of the top sequence of this level, the section from where all human remains have been recovered so far, is also presented. We have observed that the hominin stratum, previously defined as Aurora Stratum, represents a condensed deposit of at least six layers, which could not be distinguished in the test pit made in 1994-95. Therefore, the human fossil remains were probably deposited during a discrete and undetermined time period. The new mandibular fragment exhibits a very similar morphology to that of the most complete specimen, ATD6-96, which was recovered in 2003 from a different layer. This suggests that both specimens represent the same biological population. The two mandibles, as well as the small mandibular fragment ATD6-5 (which constitutes part of the holotype of Homo antecessor), present a morphological pattern clearly derived with regard to that of the African early Homo specimens usually included in H. habilis and H. rudolfensis, the mandibles D211 and D2735 from Dmanisi, and most of the early Pleistocene mandibles from Sangiran. The TD6 mandibles also exhibit some derived features with regard to the African early Pleistocene specimens included in H. ergaster (or African H. erectus). Thus, the TD6 hominins seem to represent a lineage different from other African and Asian lineages, although some (metric in particular) similarities with Chinese middle Pleistocene mandibles are noted. Interestingly, none of the apomorphic mandibular features of the European middle and early late Pleistocene hominins are present in the TD6 mandibles.

The Azokh Cave complex: Middle Pleistocene to Holocene human occupation in the Caucasus.

Azokh Cave is located near the village of the same name in the Nagorno-Karabagh region of the south-eastern part of the Lesser Caucasus (3937.09’ N and 4659.19’ E, 962 metres –a.s.l.). Azokh Cave and other relevant Acheulian sites in the Caucasus (Fig. 1) were described by Lioubine (2002). Together with Mousterian sites (Klein, 1969, 1999; Hoffecker and Cleghorn, 2000; Hoffecker, 2002; Stringer and Andrews, 2005) and sites producing evidence of the Middle-Late Palaeolithic transition (Joris and Adler 2008), the Caucasus region has provided evidence of continuous human settlement of the area throughout the Pleistocene. The geographical location of these sites indicates the persistence of a natural corridor that Lioubine (2002) named the ‘Caucasus isthmus’ and which we describe as the Trans-Caucasian corridor. Based on a geological survey of Quaternary deposits in collaboration with the Armenian Academy of Sciences (Ferna´ndez-Jalvo et al., 2004; King et al., 2003), we observe that the topography of the area has changed considerably due to tectonic compression and periglacial isostasy. This is in agreement with estimations by GPS studies (Mosar, 2006, Mosar et al., 2007) and ESR (Gru¨n et al., 1999) that establishedan uplift rate of12 to14 mm/year or 0.8–1.0 cm/year, respectively. The corridor has changed greatly since the middle Pleistocene, with uplift and erosion altering the landscape, but it is likely that passage through the Caucasian mountains has always been possible. The Trans-Caucasian corridor and other routes via Turkey and towards Asia (Bar-Yosef and Belfer-Cohen, 2001) were migration pathways during the Pleistocene. Fossil humans in the Caucasian area are scarce. The site of Dmanisi in Georgia yielded the earliest known Eurasian hominins (1.7 Ma, Gabunia et al., 2000; Rightmire et al., 2006; Martino´ n- Torres et al., 2008). Late surviving Neanderthals are present at several sites: Mezmaiskaya Cave, in the Northern Caucasus of Russia (30 ka, Skinner et al., 2005), provided remains of late surviving Neanderthals; a mandible of a 2–3 year old Neanderthal child was found at Barakay Cave (North Caucasus; Lubin et al., 2002). Two incisor fragments and one premolar from Kudaro I may be human (Lioubine, 2002). In this context, Azokh Cave fills an important temporal gap. Azokh Cave contains a nearly continuous stratigraphic section from >300 ka to the present, and mandible fragments of Homo heidelbergensis found at the site (Kasimova, 2001) represent the easternmost extent of this species. Here we review the finds of this long forgotten site and present results of our recent work.