Saurornitholestes langstoni (Sues, 1978)

Currie, P. J., 1987, Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada, Fourth Symposium on Mesozoic Terrestrial Ecosystems, Drumheller, Alberta: Tyrrell Museum of Paleontology, pp. 51-60 : 54

Saurornitholestes langstoni ( Figs. 1d , 3 )

is the most common small theropod in the Judith River Formation of Dinosaur Provincial Park, judging from the number o: frontais (Tsble l) and teeth (Currie, Rigby and Sloan, in preparation) recovered. In contrast with Dromaeosaurus , the medial prong of the nasal does not extend as far caudally over the frontal as the more lateral prong. The slot that the lacrimal passes through the frontal to contact the prefrontal. is relatively small ( Fig. 1d ). The frontal is somewhat bulbous caudally where it curves posteroventrally to meet the parietal. A faint, sigmoidally curved ridge runs rostrolaterally onto the front margin of the postorbital process, and marks the anterior limit of the supratemporal fenestra. Unlike Dromaeosaurus , the portion of the frontal within the supratemporal fenestra is posterodorsally concave, and even forms a deep pit in some specimens ( TMP 86.77.57 , Fig. 1d ).

Figures

FIG. 1 Theropod frontals from Dinosaur Provincial Park. (a) Troodon formosus. TMP 86.49. 10; (b) Dromicelomimus samueli, TMP 85.56.62; (c) cf. Erilcosaurus sp., NMC 12355; (d) Saurornitholestes langstoni, TMP 86. 77. 57; (e) Dromaeosaurus albertensis, NMC 12349, AMNH 5356; (f) cf. Aublysodon sp., TMP 80.16.485; (g) cf. Gorgosaurus libratus, TMP 80.16.924; (h) Daspletosaurus torosus (after Russell. 1970). (1) Caudal limit of dorsalateral exposure of the lacrimal; (2) caudal limit of orbital rim; (3) caudal limit of postorbital suture; (4) lacrimal slot; (5) Postorbital buttress. Scale= 1cm.

FIG. 3 Saurornitholestes langstoni (TMP 80. 16. 312). Left frontal in (a) dorsal, (b) ventral, (c) medial and (d) posterior views. Scale= 1cm.