Martha Tappen

Earliest human occupations at Dmanisi (Georgian Caucasus) dated to 1.85–1.78 Ma

The early Pleistocene colonization of temperate Eurasia by Homo erectus was not only a significant biogeographic event but also a major evolutionary threshold. Dmanisis rich collection of hominin fossils, revealing a population that was small-brained with both primitive and derived skeletal traits, has been dated to the earliest Upper Matuyama chron (ca. 1.77 Ma). Here we present archaeological and geologic evidence that push back Dmanisis first occupations to shortly after 1.85 Ma and document repeated use of the site over the last half of the Olduvai subchron, 1.85–1.78 Ma. These discoveries show that the southern Caucasus was occupied repeatedly before Dmanisis hominin fossil assemblage accumulated, strengthening the probability that this was part of a core area for the colonization of Eurasia. The secure age for Dmanisis first occupations reveals that Eurasia was probably occupied before Homo erectus appears in the East African fossil record.

LATE PLIOCENE HOMINID OCCUPATION IN CENTRAL-AFRICA - THE SETTING, CONTEXT, AND CHARACTER OF THE SENGA-5A SITE, ZAIRE

Abstract Senga 5A is a late Pliocene archaeological occurrence discovered in 1985 on the eastern bank of the Semliki River in the Western Rift Valley of eastern Zaire. Excavations in 1985 and 1986 yielded stone artifacts of an Oldowan character, fossil mammal, reptile, fish, and mollusc remains, as well as coprolites and fossil wood. The site is situated in low-energy lacustrine deposits indicative of a shallow, littoral or paludal setting. Paleoenvironmental reconstruction indicates that a savanna mosaic existed in the Upper Semliki in the late Pliocene. Dating estimates based on faunal correlation indicate an age of about 2·0–2·3 million years B.P. making it the earliest archaeological site of its size and state of preservation currently known in Africa. As the westernmost Oldowan site known in Africa, Senga 5A significantly expands our knowledge of the geographic range of early tool using hominids.

Recognizing hominoid-modified bones: The taphonomy of colobus bones partially digested by free-ranging chimpanzees in the Kibale Forest, Uganda

We present a taphonomic study of bones that have passed though the digestive tracts of free-ranging chimpanzees from the Kibale Forest in Uganda. The bone assemblage can be characterized as having a very low species diversity; low number of identifiable specimens (NISP) per scat; bones extremely broken up (very small size range); skeletal part frequencies similar in some ways to those resulting from carnivore partial digestion; and sometimes articulated specimens. Modifications to the bones include corrosion, tiny tooth scores and pits, cracking, and fraying of bone edges. Together, these characteristics suggest that hominoid bone digestion may be recognizable, despite some similarities with leopard-, canid-, and eagle-modified bone. Chimpanzees are well-documented hunters of medium-sized vertebrates such as monkeys. This is significant in the study of human evolution if, as it seems, the last common ancestor of chimpanzees and humans was chimpanzee-like. It suggests there was a pre-stone-tool-using hunting phase in human evolution, perhaps by australopiths or the last common ancestor. Taphonomically, pre-stone tool meat eating has been very difficult to detect in the fossil record. However, if chimpanzees leave a recognizable taphonomic signature on the bones of their prey, we will be able to look for analogous signatures in fossil bones associated with fossil hominoids and hominids.

Early Pleistocene enamel proteome sequences from Dmanisi resolve Stephanorhinus phylogeny.

Ancient DNA (aDNA) sequencing has enabled unprecedented reconstruction of speciation, migration, and admixture events for extinct taxa1. Outside the permafrost, however, irreversible aDNA post-mortem degradation2 has so far limited aDNA recovery within the ˜0.5 million years (Ma) time range3. Tandem mass spectrometry (MS)-based collagen type I (COL1) sequencing provides direct access to older biomolecular information4, though with limited phylogenetic use. In the absence of molecular evidence, the speciation of several Early and Middle Pleistocene extinct species remain contentious. In this study, we address the phylogenetic relationships of the Eurasian Pleistocene Rhinocerotidae5-7 using ˜1.77 million years (Ma) old dental enamel proteome sequences of a Stephanorhinus specimen from the Dmanisi archaeological site in Georgia (South Caucasus)8. Molecular phylogenetic analyses place the Dmanisi Stephanorhinus as a sister group to the woolly (Coelodonta antiquitatis) and Merck’s rhinoceros (S. kirchbergensis) clade. We show that Coelodonta evolved from an early Stephanorhinus lineage and that this genus includes at least two distinct evolutionary lines. As such, the genus Stephanorhinus is currently paraphyletic and its systematic revision is therefore needed. We demonstrate that Early Pleistocene dental enamel proteome sequencing overcomes the limits of ancient collagen- and aDNA-based phylogenetic inference, and also provides additional information about the sex and taxonomic assignment of the specimens analysed. Dental enamel, the hardest tissue in vertebrates, is highly abundant in the fossil record. Our findings reveal that palaeoproteomic investigation of this material can push biomolecular investigation further back into the Early Pleistocene.