part of part of subdivision of skeletal system cranium lateral commissure UBERON:4300134 Region of the braincase which bears the facets for the hyomandibula in fishes. This region disappears in the origin of tetrapods and the space it occipied comes to contribute to the fenestra vestibulii. Clack, JA, 2001. Ch. 23, The otoccipital region. In Major Events in Early Vertebrate Evolution. Per Ahlberg editor. Wasila M Dahdul