Metatarsals and foot phalanges from the Sima de los Huesos Middle Pleistocene site (Atapuerca, Burgos, Spain)

This study provides a complete, updated and illustrated inventory, as well as a comprehensive study, of the metatarsals and foot phalanges (forefoot) recovered from the Middle Pleistocene site of Sima de los Huesos (SH, Atapuerca, Spain) in comparison to other Homo comparative samples, both extant and fossils. This current updated review has established a minimum number of individuals (MNI) of 17, which represent 58.6% of the 29 dental individuals identified within the SH sample. An exclusive or autoapomorphic combination of traits can be recognized within the SH hominin foot sample. A few traits appear primitive or plesiomorphic when compared with earlier Homo individuals and other recent modern humans. There are other metrical and morphological traits that SH hominins and Neandertals have in common that sometimes represent shared derived traits in this evolutionary line, most of which are probably related to robusticity. Furthermore, some exclusive autoapomorphic traits are observed in the SH sample: a very broad first metatarsal, long and broad hallucal proximal foot phalanges and possibly extremely robust lateral distal foot phalanges compared to those of Neandertals and modern humans. In these last traits, the SH metatarsals and pedal phalanges are even more robust than in Neandertals. They are herein named as "hyper-Neandertal" traits, which could suggest a slight gracilization process in this evolutionary line, at least in the hallux toe. Finally, some paleobiological inferences are made in relation to body size (stature and body mass) and some associations are proposed within the SH sample.

Taphonomic skeletal disturbances in the Sima de los Huesos postcranial remains

The postcranial skeleton of fossil hominins is crucial for reconstructing the processes that occurred between the time of death and the recovery of the bones. Thousands of postcranial skeletal fragments from at least 29 hominin individuals have been recovered from the Sima de los Huesos Middle Pleistocene site in Spain. This study's primary objective is to address the main taphonomic features of the postcranial remains from the Sima de los Huesos sample, including antemortem, perimortem, and postmortem skeletal disturbances. We present an updated assessment of the bone surface modification analysis, the fracture pattern analysis, and the skeletal part representation to facilitate interpretation of the biostratinomic and fossil-diagenetic processes in this large paleoanthropological collection. We conclude that carnivores (probably bears) had limited access to the hominin bones and complete bodies were probably placed in the site.

Unearthing Neanderthal population history using nuclear and mitochondrial DNA from cave sediments

Bones and teeth are important sources of Pleistocene hominin DNA, but are rarely recovered at archaeological sites. Mitochondrial DNA (mtDNA) has been retrieved from cave sediments but provides limited value for studying population relationships. We therefore developed methods for the enrichment and analysis of nuclear DNA from sediments and applied them to cave deposits in western Europe and southern Siberia dated to between 200,000 and 50,000 years ago. We detected a population replacement in northern Spain about 100,000 years ago, which was accompanied by a turnover of mtDNA. We also identified two radiation events in Neanderthal history during the early part of the Late Pleistocene. Our work lays the ground for studying the population history of ancient hominins from trace amounts of nuclear DNA in sediments.

Neandertal foot remains from Regourdou 1 (Montignac-sur-Vézère, Dordogne, France)

Regourdou is a well-known Middle Paleolithic site which has yielded the fossil remains of a minimum of two Neandertal individuals. The first individual (Regourdou 1) is represented by a partial skeleton while the second one is represented by a calcaneus. The foot remains of Regourdou 1 have been used in a number of comparative studies, but to date a full description and comparison of all the foot remains from the Regourdou 1 Neandertal, coming from the old excavations and from the recent reanalysis of the faunal remains, does not exist. Here, we describe and comparatively assess the Regourdou 1 tarsals, metatarsals and phalanges. They display traits observed in other Neandertal feet, which are different from some traits of the Sima de los Huesos (Atapuerca) hominins and of Middle Paleolithic, Upper Paleolithic and recent modern humans. These Neandertal features are: a rectangular talar trochlea with a large lateral malleolar facet, a broad talar head, a broad calcaneus with a projecting sustentaculum tali, a wide and wedged navicular with a projecting medial tubercle, large and wide bases of the lateral metatarsals, and mediolaterally expanded and robust phalanges that also show hallux valgus in a strongly built hallux.