Joint Seminar: Calcium stable isotopes / Middle Pleistocene suid predation

SÉMINAIRE / SEMINAR

Evolution: an international research seminar in Eastern Africa. Paleobiodiversity, paleobiology, prehistory, paleoenvironments (2015-2019)

24^ème séance / 24^th session:

1- Calcium stable isotopes in paleontology and paleoanthropology
par /by Vincent Balter

2- A possible case of human predation by blunt force cranial trauma on a large suid (Kolpochoerus majus) from Bodo (Middle Pleistocene, Ethiopia): insights from experiments on extant wild boars (Sus scrofa) 
par /by Antoine Souron

Mercredi 15 mai 2019, 15h-17h / Wednesday, May 15, 2019, 3:00-5:00 pm

Lieu /Venue: Authority for Research and Conservation of Cultural Heritage, Meeting Hall (room 308)

1- Calcium stable isotopes are becoming a tool of choice for paleontological studies. In this presentation, Vincent Balter will discuss the advantages of the method and the potential applications in vertebrate paleontology will be illustrated by differents studies on dinosaurs and hominids.

2- For much of their evolutionary history, hominids likely had little predatory impact on other large animals and frequently fell prey to large carnivorous animals (mammals and crocodiles). The archaeological record indicates that later hominids (definitely after 2.6 Ma and probably earlier) gradually incorporated more meat into their diet than observed in extant chimpanzees, either through hunting or scavenging. To understand the timing and processes of the transition from occasional meat-eater to adept hunter, it is crucial to estimate to what extent early hominids obtained meat through hunting or scavenging. Killing animals with a blow to the head using a blunt object is common in recent archaeological, historical, and ethnographic contexts, and it was likely also a common behavior of earlier hominids, although direct evidence during the Plio-Pleistocene is scarce. To facilitate the identification of such predation in the past, Antoine Souron conducted actualistic experiments on a collection of 23 heads of freshly dead extant wild boars (Sus scrofa) from Tautavel, France. He investigates the influence of various factors on the morphology and size of the resulting cranial fractures: shape, size, and raw material of the striking object, force and angle of the impact, state of the impacted bone (fresh versus dry), as well as biological age (estimated using dentition and cranial sutures) and size of the impacted specimens. He compares the results from these experiments to a specimen from the Middle Pleistocene: a fossil cranium of a large extinct suid (Kolpochoerus majus) from the Upper Bodo Sand Unit sediments (Middle Awash Valley, Afar Depression, northern Ethiopia), dated to around 600 ka. This cranium displays a deep, well-delimited oval depressed fracture located on the cranial vault between the orbits, with all the diagnostic characteristics of peri-mortem blunt force traumatic injuries on fresh bone. The occipital bone of the same specimen also displays linear marks that he interprets as cut marks made when disarticulating the head from the body after the killing. This specimen is thus one of the earliest possible cases of direct evidence for large mammal hunting behavior and butchery in the fossil record.

The speakers

Vincent Balter is a CNRS researcher in geochemistry, working at the ENS in Lyon (France). His main research focus is on stable isotope metabolism and on geochronology of the Quarternary. 

Antoine Souron defended his Ph.D. thesis in Paleontology at the University of Poitiers (France) in 2012. He continues his research as a Junior Chair at the IdEx University of Bordeaux, mainly on the paleoecology of suids  (pigs), he is a member of the Omo Group Research Expedition.