Getting inside the bones

The European bison,or Wisent, (Bison bonasus) is Europe’s largest land mammal and the last surviving large grazer from a time of real giants. However, during most of the history of the species, it coexisted with other large bovines. One more familiar species was the Aurochs (Bos primigenius), the ancestor of modern domestic cattle, that went extinct in the 17th century. In Southern Scandinavia the two species coexisted for a brief period of time.

Both the Aurochs and the European bison colonized the area via a land bridge connecting southern Sweden, the Danish Isles and mainland Europe about 11,000 years ago. Remarkably, the European bison seem to have disappeared 9,600 years ago, possibly because the forests grew denser and they became isolated from the continental bison population when the land bridge was cut off due to rising sea levels. The aurochsen seem to have prevailed longer, disappearing from southern Sweden and Denmark about 7000 years ago and 3000 years ago, respectively.

The extent of the ice sheet at the Last Glacial Maximum, around 20,000 years ago. Huge ice sheets covered much of northern Europe. With water trapped in the ice, sea levels were lower, and more land was connected. (Image Public Domain)

Remains of aurochsen are relatively abundant in bogs and at prehistoric human settlement sites, but only about 20 confirmed finds of European bison have been made in southern Scandinavia. This skewed ratio of finds between the two species has been proposed to reflect differences in choice of habitat due to competition or human disturbance as well as an actual difference in population sizes.

The beautiful European Bison (Bison bonasus) in Réserve biologique des Monts d’Azur, Haut-Thorenc, France (Photo Valène Aure)

Although the animals looked quite different, the complete skulls are the only individual bone elements that can be positively identified as either aurochs or European bison. This means that the bones in archaeozoological assemblages, which usually are highly fragmented due to their exploitation by man as resources for food and raw materials, pose a particular challenge for species identification. As a consequence of this, one can suspect that some remains of European bison might have been misinterpreted as aurochs in previous analyses. This is common in museum collections across Europe: many specimens lay in drawers labelled as Bovine, because the post-cranial bones of the two species are so similar.

An almost complete skeleton of a European bison found at the end of the 18th century in southern Sweden. (Photo by Lucas Gölén)

In a pilot study, researchers from Lund University, Sweden, and the Universities of York and Manchester (UK), plan to analyse bone powder from the skulls of one prehistoric European bison and one aurochs. The samples will be analysed for collagen-peptide sequencing using Zooarchaeology by Mass Spectrometry (ZooMS), a method previously used to successfully discern bone fragments from sheep (Ovis aries) and goats (Capra hircus) in archaeological assemblages. The bones of these two species are fairly similar in size and shape, and it has often proven very difficult to identify the individual species.

The purpose of the study is to investigate whether ZooMS is a feasible method for species identification of European bison and aurochs in various prehistoric bone assemblages. It is hoped that the species-specific peptide identified through the reference samples can then be used to distinguish fragments of uncertain taxonomic status. So many bone assemblages from sites contemporary with the known presence of bison in Scandinavia have previously identified as bovine and we’re aware it will need to be totally re-examined. It is hoped that the results will help to increase the number of European bison finds, increase our understanding of the species’ local history and its importance as a food source to prehistoric humans.

Written by Erika Rosengren (@RosengrenErika)

Edited by Rena Maguire (@JustRena)

For a description of the ZooMS method see: https://youtu.be/xBAXaLvGe5I

Contact: Erika Rosengren, Osteological Collections Curator. Lund University Historical Museum. Erika.Rosengren@luhm.lu.se

Further reading:
Benecke, N., (2005). ‘The Holocene distribution of European bison – the archaeozoological record’. Munibe (Anthropologia-Arkeologia) 57. pp. 421-428.

Buckley, M., Whitcher Kansa, A., Howard, S., Campbell, S., Thomas-Oates, J. & Collins, M. (2010). ‘Distinguishing between archaeological sheep and goat bones using a single collagen peptide’. Journal of Archaeological Science. 37. pp. 13–20.(http://www.sciencedirect.com/science/article/pii/S0305440309002854)

Ekström, J. (1993). ‘The late Quaternary history of the urus (Bos primigenius Bojanus 1827) in Sweden’. Lundqua Thesis 29.

Rosengren, E. (2014). ‘Sven Nilsson and the postglacial fauna of Scania’. Lund University Historical Museum. Lund.