Crania (brachiopod)Crania is an extinct genus of brachiopods that lived during the Upper Cretaceous.DescriptionCrania has small circular shells. The dorsal valve is smooth or has slight pustules. The ventral valve is only attached posteriorly and has a thickened flat grainy rim.Reassigned speciesAs the genus Crania was erected early on in paleontology, many species have since been reassigned.