9423428 Rowe This project is a study of the evolutionary relationships among living crocodylians and their closest extinct relatives (eusuchians) based on morphologic characters from the skull and postcranial skeleton. The use of computed tomographic or CT scanning will permit study of detailed aspects of cranial morphology and provide an additional source of characters for analysis. %%% The study of crocodylian evolutionary relationships is significant in terms of including for the first time both fossil and living taxa and characters from the postcranial skeleton. Beyond establishing a phylogeny for crocodylians, this study will investigate character evolution in relation to aquatic adaptation and the role of differences in developmental timing (heterochrony) in crocodylian evolution. ***