The epiotic is often small, ossifies irregularly, and fuses with the supra-occipital.
The opisthotic lies between the epiotic and the lateral occipital with which it ultimately fuses; in some birds, e.g.
This supposition is supported by a specimen from the Lower Permian of Autun, determined as Actinodon frossardi, acquired in 1902 by the British Museum, which shows a bone, similar to the so-called "epiotic cornu" of the microsaurians, Ceraterpeton and Scincosaurus, to have the relations of the supra-cleithrum of fishes, thus confirming a suggestion made by C. W.
H, Of the optic. Ep, Epiotic process.