The skull of Velociraptor - Acta Palaeontologica Polonica

ACTA PALAEONTOLOGICA POLONICA (44) (2) 195
Fig. 2. Skull with mandible of Velociraptor mongoliensis GIN 100125. A. Occipital view, stereophoto-
graph. B. Dorsal view, stereophotograph, GIN 100125. C. Tooth of Velociraptor mongoliensis, ZPAL
MgD-I/97a. Scale bars 2 cm for A and B, 2 mrn for C.
Snout
Premaxilla. - The main body of the premaxilla is longer than high. A long, thin maxillary process
of the premaxilla is wedged between the maxilla and nasal, reaching caudally to or close to the rostral
margin of the antorbital fossa, and it separates the maxilla from the naris. In the extreme case (GIN
100/25), on the right side of the skull, this process extends even farther, to a point above the fifthlsixth
maxillary teeth. The nasal process has a stout base, but its internarial portion is thin, and its end fits
into a medial groove present along the tip of the nasal. A shallow depression in the premaxilla out-
lines the rostral and ventral margins of the narial opening. At the contact with the maxilla, the
caudoventral border of the premaxilla is slightly embayed to mark the subnarial foramen. The surface
of the rostral and alveolar parts of the premaxilla bears small, irregularly spaced foramina. In palatal
view, the rostral portion of the premaxilla is steep, and only below the naris is there a narrow palatal
shelf. The premaxillary shelves contact each other on the mid-line. They separate caudally, leaving
a triangular space below the narial openings, where tip of the fused vomers is inserted.