Geographical variation in the size and shape of the European aurochs (Bos primigenius)

The aurochs (Bos primigenius) is generally agreed to be the wild ancestor of domestic cattle (Bos taurus) and an in-depth knowledge of this animal is therefore key to research exploring human-cattle interactions, and the origins and spread of cattle domestication. Domestic cattle are smaller than their wild ancestors, but there is also a degree of overlap between the two species, which means that distinguishing them can be problematic. However, previous analyses of aurochs morphology have generally been patchy, and do not provide a picture of aurochs variation across Europe according to environment, climate and geography. As a consequence, zooarchaeologists often refer to comparative biometrical data from geographical areas and time periods which may not be suitable for identifying remains from their study area. This paper presents results from a wide-ranging study of aurochs biometrical data, in order to provide an overview of its morphological variation across Europe, and highlight the importance of using geographically and climatically appropriate comparative data when attempting to identify and interpret the significance of aurochs remains. We also propose a set of 'standard' measurements from an aurochs population excavated at the site of Ilford (Essex, UK) dated to Marine Isotope Stage 7 with the hope that they will be of use to others seeking a suitable standard for the biometrical analysis of cattle populations, especially when looking for the presence of wild specimens.