ABSTRACT
The types of actinopterygian skull bones and their origins have recently been discussed in Grande and Bemis and Arratia but are worth restating. Ontogenetically, the skull is formed by the endocranium, splanchnocranium and dermatocranium. Orienting from anterior to posterior and from medial to lateral, the dorsal surface of the cranium consists of the following bones: mesethmoid, lateral ethmoids, nasals, frontals, sphenotics, pterotics, parietals, epiotics, and supraoccipita. Variation in mesethmoid size and shape is common among gonorynchiforms. The bones that constitute the cranium in ventral aspect are the mesethmoid, lateral ethmoids, vomer, parasphenoid, pterosphenoids, sphenotics, pterotics, prootics, intercalar, basioccipital, and exoccipitals. The cheek bones are the most superficial bones on the lateral surface of the osteichthyan skull. In gonorynchiforms, they are flat, often support the cephalic lateral line canals, and, as in most osteichthyans, can be ornamented.
