Figure 2 in Dromaeosaurid crania demonstrate the progressive loss of facial pneumaticity in coelurosaurian dinosaurs

Figure 2. Craniofacial pneumaticity of Velociraptor. Skull AMNH FARB 6515 in (A, C) lateral and (B, D) medial views, with the rostrum in (E) lateral and (F) medial views. Abbreviations: aofen, antorbital fenestra; aof, antorbital fossa; mf, maxillary fenestra; mx, maxilla; pmf, promaxillary fenestra; mi, maxilla interior;?pipf, premaxillary pneumatic foramina; pmx, premaxilla; pf, pneumatic foramina of the frontal; front, frontal; nf, neurovascular foramina; rugose, rugose bone surface; smooth, smooth bone surface. In (C) and (D), light blue are neurovascular foramina, light green is the maxillary fenestra, light red is the promaxillary fenestra, tan is an additional maxillary fenestra.