Kansasiella eatoni

Kansasiella eatoni

The general proportions of the orbital region of Kansasiella eatoni mirror Phoebeannaia excepting the supraorbital shelf, which bears a deep groove and laterally encloses the forebrain to a greater extent, and smaller basipterygoid processes (bpt.p; Figs 7C, 8E, 9C, 10C, D), consistent with Poplin’s (1974) description. The posterior myodome and buttressing of the basisphenoid pillar are remarkably similar to Phoebeannaia , though details surrounding the passage of the hypophysis are lacking due to cracks in the specimen. Ventrally, the surface of the basisphenoid is mostly obscured by the parasphenoid. Foramina for the oculomotor (III; Fig. 10C, D) and trochlear (IV; Fig. 10C, D) nerves are clearly preserved. The channel through which the trigeminal nerve and gasserian ganglia must have passed (V.so,lat; Fig. 10C, D) is somewhat recessed into the jugal canal and enclosed by a bridge of bone similar to the ‘alisphenoid pedicel’ (a.ped; Fig. 10C) described in Moythomasia durgaringa ( Gardiner, 1984) . While this recess primarily opens ventrally into the jugal canal, there is another passage that opens dorsally into the deep groove on the supraorbital shelf that probably marks the path of the supraopthalmic branch of the trigeminal and lateralis nerves (groove for the superopthalmic branch of the trigeminal nerve [gr.V.so]; Fig. 10D). The groove runs the length of the orbital region, though there is a dorsal foramen (lat.f; Fig. 10C) directly above the passage from the trigeminal chamber that might have transmitted one or more nerves into the intracranial space.

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