Abstract
Pawpawsaurus campbelli gen. et sp. nov. from the Paw Paw Formation (late Albian), Tarrant County, Texas, appears more primitive than other pre-Campanian nodosaurids, Silvisaurus condrayi and Sauropelta edwardsi. New cranial synapomorphies for the Nodosauridae are prominent W-shaped basioccipital tubera, anteriorly concave and anteroposteriorly flattened quadrate, and transversely continuous and straight posterior margin of the pterygoid aligned with the quadrate shaft. These synapomorphies are closely related to the downward orientation of the nodosaurid head in life. A pair of bony eyelids recovered with the skull are the first discovered for the Nodosauridae. Other Paw Paw Formation nodosaurid remains, including new postcranial elements and a baby nodosaurid, are taxonomically indeterminate.