Multivariate analysis on Lower Cretaceous dinosaur footprints: Discrimination between ornithopods and theropods

Abstract

The discrimination of ornithopod from theropoddinosaur footprints can sometimes be problematical. In order to obtain discriminatory criteria, an analysis BMDP (4M, 7M) on a sample of 66 Lower Cretaceous tridactyl footprints of diverse geographical origins has been carried out. The more significant ichnological parameters explaining sample variability are related with the digital widths and with the whole dimensions of the footprints. Some other parameters, such as digital angulation (often used as an important discriminatory criterion), seem to be of limited significance. Based on the more significant ichnological parameters, some indices have been proposed. These indices are used in bivariate analyses which allow to discriminate ornithopod from theropod footprints with a different degree of confidence.