Boyer diss 2009 1046..

process is quite large, projecting ventrally beyond the glenoid fossa by 2.5 mm (Figs. 3.4,
5: 30). It is oriented longitudinally at roughly 90 degrees from the orientation of the
postglenoid process, and slopes medially. The glenoid is rather flat and anteroposteriorly
longer (11.52 mm) than mediolaterally wide (10.12 mm). HRxCT imagery seems to
reveal a sinus space within the squamosal medial to the anterior half of the left glenoid.
A sinus that balloons out into the endocranial space would have reduced the endocranial
volume as compared to a case in which such sinuses were lacking.
Sphenoids.— Fragments of the alisphenoid and basisphenoid are preserved, but
shifted into the endocranium (Figs. 3.5, 7: 31-32). The boundary between the two bones
is not discernable; however, the bases of the entopterygoid (basisphenoid) and
ectopterygoid (alisphenoid) processes are visible. HRxCT imagery reveals a cylindrical
trough (most clearly on the left side) on the endocranial surface above the pterygoid
processes that would have held the ophthalmic and/or the maxillary divisions of CN V
(trigeminal nerve) (Fig. 3.7: 33). The trough appears mainly undistorted for a short
distance and has a diameter measuring 1.90 to 2.10 mm in this interval. At the
convergence of the pterygoid crests is a canal that may represent the former location of
the vidian nerve (Fig. 3.7: 34). The foramina connecting this canal to extracranial space
are minute and asymmetrical. The interpretation of their function is thus tentative. More
posteriorly, HRxCT imagery of the fragmented remains of the basisphenoid suggest the
presence of large sphenoidal sinus spaces, but the fossil is extremely battered in this
region and this interpretation is tentative.
Petrosal.— The pars cochlearis of both petrosals is preserved, but the left element
is obscured underneath a crushed bulla (Fig. 3.5: 35). The pars canalicularis (Fig 5: 36)
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