Crouching theropod at the seaside. Matching footprints with metatarsal impressions and theropod authopods: a morphometric approach

We compare theropod footprints with elongate metatarsal prints from central Italy with known autopod structures in major theropod groups, in order to more accurately define the trackmaker attribution. Our work, using morphometric analysis, shows the considerable potential of explorative methods such as PCA (principal component analysis) and cluster analysis when describing important characters for a given taxonomic group (body and ichnofossils) and identifying important anatomical regions. Moreover, the results of the analysis suggest that the putative trackmaker is likely a member of Ornithomimosauria, with significant affinities in the posterior autopod structure with the genus Struthiomimus. The fundamental importance of integrating both osteological and ichnological data, when investigating locomotor and behavioural hypotheses, is highlighted. This approach could also contribute positively to the complex cognitive process of trackmaker identification and be favourable for the attainment of a more natural definition of ichnotaxa.