intertemporal postparietals 



parietal 

 postfrontal 

 prefrontal 

 nasal series 



snout shield 



dentary 



angular 



posterior marginal gular 



suproangular scales 



snout shield 



snout shield 



anterior spleniol 



anterior medial gular 

 posterior spleniol 



angular 



Figure 4-36. Dermal head skeleton of Dipterus plotycephalus. A, lateral view; B, dorsal view; 

 C, ventral view. (After Westoll, 1949) 



Embryo/ogical devo/opmenf The development of the cms- are the autostylic suspension of the palatoquadrate and the 



sopteryi^ian head skeleton is not known but that of the fragmentation of the hyoid arch. 



dipnoan is summarized in Figure 4-39. The similarity to The palatoquadrate develops an -""^'ng process wh^^^^ 



the amphibian (Figure 4-19) is marked and could be inter- passes lateral to the profundus (V,) branch of the trigem ma 



preted as relations^p or parallelism. Of particular interest and fuses to the orbital cartilage. An otic process attaches 



100 • HEAD SKELETON OF OTHER TETRAPODS AND CHOANATES 



