Velociraptor mongoliensis, Osborn, 1924

Brownstein, Chase Doran, 2021, Dromaeosaurid crania demonstrate the progressive loss of facial pneumaticity in coelurosaurian dinosaurs, Zoological Journal of the Linnean Society 191 (1), pp. 87-112 : 97

Velociraptor mongoliensis

The antorbital sinus in Velociraptor would have been dorsoventrally compressed anteriorly relative to that of Deinonychus due to the more elongate maxilla of the former taxon ( Fig. 4A, C ). The antorbital fossa invades the maxilla to a similar degree as in Deinonychus and other dromaeosaurids (e.g. Norell & Makovicky, 2004; Norell et al., 2006; Turner et al., 2012; Evans et al., 2013). However, the border of the antorbital fossa in Velociraptor mongoliensis is strongly undercut anteriorly, ventrally and dorsally in the maxilla and other bones that make up this feature, suggesting the antorbital sinus was fully placed within the antorbital fossa and bordered by the maxilla, lacrimal and jugal. The anterior diverticula of the antorbital sinus (especially the maxillary antrum) seem to have been slightly larger in Velociraptor than in Deinonychus , as the maxillary fenestra in the former taxon is wider dorsoventrally.

Figures

Figure 4. Reconstruction of the antorbital sinus in coelurosaurs. The second sentence in the figure caption should read: Skulls of (A) Velociraptor, (B) Tsaagan, (C) Tyrannosaurus, (D) Deinonychus, (E) Saurornithoides, and (F) Khaan. Antorbital sinus in blue, with location of the maxillary fenestra in black and promaxillary fenestra in yellow. Photo of Deinonychus courtesy of the Division of Vertebrate Paleontology, Peabody Museum of Natural History.