Abstract

In lizards, a short Vidian canal pierces the base of the basipterygoid process. In snakes, the anterior opening of the primitively short Vidian canal lies on the dorsal surface of the basisphenoid, trapped in an intracranial position by downgrowths of the frontal and parietal which meet the lateral edges of the basisphenoid-parasphenoid complex. This condition is observed in anilioid snakes which retain other primitive features in the braincase: the paroccipital process and the spheno-occipital tubercle (Aniliidae only) and participation of the basioccipital in the apertura lateralis of the recessus scalae tympani.

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