Comparative Osteology of the Jaws in Representatives of the Eurypterygian Fishes

The osteology of the jaws in representatives of 49 genera in 40 families of eurypterygian fishes, including: Aulopiformes, Myctophiformes, Lampridiformes, Polymixiiformes, Percopsiformes, Mugiliformes, Atheriniformes, Beloniformes, Cyprinodontiformes, Stephanoberyciformes, Beryciformes, Zeiformes, Gasterosteiformes, Synbranchiformes, Scorpaeniformes (including Dactylopteridae), and Perciformes (including Elassomatidae) were studied. Generally, in this group, the upper jaw consists of the premaxilla, maxilla, and supramaxilla. The lower jaw consists of the dentary, anguloarticular, retroarticular, and sesamoid articular. In higher taxa, the premaxilla bears ascending, articular, and postmaxillary processes. The maxilla usually bears a ventral and a dorsal articular process. The supramaxilla is present only in some taxa. The dentary is usually toothed and bears coronoid and posteroventral processes. The retroarticular is small and located at the posteroventral corner of the anguloarticular.