ABSTRACT
A nearly complete skull of Eutretauranosuchus delfsi was uncovered at the upper Jurassic Dry Mesa Dinosaur Quarry in the Brushy Basin Member of the Morrison Formation in western Colorado. It permits an expanded description of the taxon. Like the holotype, from Canyon City, Colorado, the Dry Mesa specimen probably represents a subadult, based on faint parallel lineations in the frontal, incomplete ossification in the otic region, incomplete sculpturing of the dermal bone, and an incompletely fused occipital condyle. The Dry Mesa specimen is compared with the type specimen, crocodyliformes Amphicotylus, photographs of the type specimen, and other related crocodyliformes described in the literature. A phylogenetic analysis lends support to a close relationship between Eutretauranosuchus, Calsoyasuchus, and Sunosuchus.
ACKNOWLEDGMENTS
We wish to thank P. Galton, J. Kirkland, K. Cloward, C. Miles, D. DeBlieux, and M. Hayden for their comments and making their libraries and facilities available. R. Scheetz (BYU) permitted further examination of the Dry Mesa specimen and use of the BYU computer. TNT was made available with the support of the Willi Hennig Society. G. Jackson (CMNH) supplied photographs of the type specimen of Eutretauranosuchus delfsi. M. Ryan (CMNH) loaned the holotype specimen of Eutretauranosuchus for comparison. M. Turner and M. Norell permitted access to specimens at the YPM and AMNH, respectively. R. Edwards photographed AMNH 5782. P. Galton, S. Salisbury, R. E. Molnar, J. Harris, A. Tumarkin-Deratzian, W. Miller, M. Snyder, C. Brochu, D. Schwarz, J. Müller (editor), and two anonymous reviewers read the manuscript at various stages and made valuable suggestions. R. E. Molnar provided plates from Kälin's 1933 monograph on crocodile skulls. J. Harris, R. E. Molnar, and M. Brandalise de Andrade made copies of some journal articles available. S. Murray assisted with lodging in the Salt Lake City area.