A LATE CRETACEOUS NODOSAURID ANKYLOSAUR (DINOSAURIA, ORNITHISCHIA) FROM MARINE-SEDIMENTS OF COASTAL CALIFORNIA

A partial nodosaurid ankylosaur skeleton, consisting primarily of the ilia, hindlimbs, posterior dorsal armor, plus partial forelimb element s and additional armor, was recovered from the marine Point Loma Forma tion, late Campanian age, north of San Diego, California. The specimen is similar to contemporaneous species of Panoplosaurus and Edmontonia from terrestrial sediments of the western interior, but there are als o similarities to the armor of Stegopelta landerensis from marine sedi ments of earliest Cenomanian age from Wyoming. Skeletal elements criti cal for generic determination are not preserved, and the specimen is i dentified as Nodosauridae, incertae sedis. An associated marine invert ebrate fauna and nannoplankton flora have revealed some discrepencies in the correlation systems used for Upper Cretaceous marine rocks of c oastal California. Hollow limb bones of the specimen are interpreted a s a preservational artifact. Nodosaurids had broad ecological toleranc es, and visited riparian and coastal environments more frequently than other dinosaurs. However, a review of morphologic and distributional evidence fails to support a theory of amphibious or aquatic habits for nodosaurids.