Edmontonia, Sternberg, 1928

Kenneth Carpenter & D. Bruce Young, 2002, Late Cretaceous dinosaurs from the Denver Basin, Colorado, Rocky Mountain Geology 37, pp. 237-254 : 249

Family NODOSAURIDAE

cf. Edmontonia sp.

Figure 18

Material. — DMNH 25915 scute (Denver Formation, Loc. 20); DMNH 39036 scute (Denver Formation, Loc. 18); DMNH 44389 tooth (Denver Formation, Loc. 20); and UCM 7572 partial basicranium (Laramie Formation, Loc. 2).

Description and discussion. —The basicranium was found by the Colorado Geological Survey, although the collecting date is not known. It was briefly described and illustrated by Carpenter and Breithaupt (1986) as one of the few specimens of Maastrichtian nodosaurids. The specimen has the characteristic crescentic occipital condyle, which projects posteroventrally from a moderately long neck ( Fig. 18 ). The main body of the basicranium includes the basioccipital and a portion of the basisphenoid. The floor of the braincase is preserved, but it lacks any meaningful detail about the various cranial foramina.

Both the scute and tooth more closely resemble those of the nodosaurid genus Edmontonia than those in the contemporary Ankylosaurus .

Figures

Figure 18. Basicranium of Edmontonia sp. (UCM 7572) in left lateral (A) and ventral (B)views, from Laramie Formation.