A new crocodylomorph specimen from the Araripe Basin(Crato Member, Santana Formation), northeastern Brazil

摘要

The fossil fauna of the Santana Formation(Early Cretaceous) comprises many distinct taxa, butcrocodylomorphs are poorly understood. Here we describea new specimen (MPSC-R1137) that consists of a completehind limb found in the Crato Member, the basal section ofthe Santana Formation. Based on the characteristics of thefibula (e.g., pronounced variation of the shaft width) andlength proportions of the femur and tibia, this specimen canbe distinguished from Caririsuchus camposi and Arari-pesuchus gomesii, which are known from the RomualdoMember (the upper lithostratigraphic unit of the SantanaFormation). The only crocodylomorph formally describedfrom the Crato Member is Susisuchus anatoceps, whoseholotype lacks elements of the hind limb. On the basis of acomparative anatomical study of the hind limb, whichshows no similarities between MPSC-R1137 and othercrocodylomorphs from the Araripe Basin, we tentativelyclassify this new specimen as cf. Susisuchus sp., and pro-vide new anatomical information for this rather derivedcrocodylomorph