An amended description of the theropod footprint Bueckeburgichnus maximus Kuhn 1958, and its bearing on the megalosaur tracks debate

Abstract

The ichnospecies Bueckeburgichnus maximus (Kuhn 1958) is amended and illustrated on the basis of type and topotype material, from the Lower Cretaceous of Germany, showing that previous illustrations were morphologically incorrect and misleading. The track is unequivocally that of a large functionally tridactyl theropod, but can not confidently be attributed to a megalosaurid dinosaur, as suggested by ichnological tradition. Bueckeburgichnus has been compared with theropod tracks from the Upper Jurassic of Portugal labeled as Eutynichnium, Megalosaurus, Megalosauripus and Megalosauropus, but the comparisons are tenuous and compromised by invalid ichnotaxonomic treatment of all four ichnogenera. Megalosaurus must be abandoned as an ichnotaxonomic descriptor. The status of Megalosauripus, Megalosauropus and Eutynichnium is under further investigation but preliminary results suggest that Bueckeburgichnus maximus is distinct from any ichnospecies assigned to these two ichnogenera.