Extinct Horned Crocodile Figure 4. Cranial remains referred to Crocodylus anthropophagus. KNM CROC K OLD 62: anterior end of rostrum, dorsal (A) and ventral (B) view; partial frontal with portions of prefrontals in dorsal (C) and anterior (D) view; right otic region and quadrate ramus, lateral view (E). KNM FLKNI: partial orbital region, dorsal view (F); left maxilla, ventral view (G); right maxilla, medial (H), lateral (I), ventral (J), and dorsal (K) view; right squamosal, posterior (L), dorsal (M), and lateral (N) view. NHM R.5893: orbital region, dorsal view (O); partial right maxilla, ventral view (P); partial right maxilla and ectopterygoid, ventral view (Q); partial palatines and pterygoids, ventral view ( R); partial right jugal, lateral (S) and medial (T) view. Scale = 5 cm. doi:10.1371/journal.pone.0009333.g004 No complete dentaries are preserved, but based on preserved specimens (Fig. 6), there were at least fourteen alveoli on each ramus. The fourth alveolus was enlarged, and the third was not confluent with it. Alveoli are circular, and a diastema separates the eighth and ninth. The tenth and eleventh are enlarged relative to the anterior alveoli. The dentary symphysis extends to the level of the fifth dentary alveolus, or to a level immediately behind it. Lateral sulci between the seventh through ninth alveoli would have received opposing maxillary teeth. The splenials do not meet at the midline. Its anteriormost extent is ventral to the slender Meckelian groove on the dentary at approximately the level of the sixth dentary alveolus (Fig. 6E). The splenial expands posteriorly and contributes to the medial alveolar borders beginning with the tenth dentary alveolus. It forms the anterodorsal border of the relatively large oval caudal foramen intermandibularis oralis, and there is no evidence for an anterior perforation. One left (KNM BK II OLD 1960, Fig. 6A) and one right (KNM FLKNI) coronoid are preserved. Each is mediolaterally flat and communicates with the splenial anteriorly, angular ventrally, and (to a minor extent) the surangular dorsally. The actual outline is imperfectly preserved in both cases, but the KNM BK II mandible reveals a small medial foramen intermandibularis oralis. The dorsal ramus projects posteriorly for a short distance medial to the surangular, and its dorsal margin is oriented anteroposteriorly and does not slope anteriorly. The ventral ramus forms the ventromedial border of the adductor chamber. The coronoid appears to contribute to the caudal formen intermandibularis oralis, on the KNM specimen, but this most likely results from dorsoventral compression. The angular has a broadly convex ventral surface. Its medial lamina forms the posteroventral and part of the dorsal margin of the caudal foramen intermandibularis oralis. Its lateral surface is smooth and unpitted where it forms the ventrolateral portion of PLoS ONE | www.plosone.org 6 February 2010 | Volume 5 | Issue 2 | e9333