pterygoid fontanelie, which is presumed to be more Hke a 

 crossopterygian fish and therefore primitive. There was a 

 toothed ectopterygoid and a small epipterygoid in the 

 palatoquadrate complex. The vomers were broad plates 

 and the parasphenoid had a long, slim rostral process. 

 There were distinct basipterygoid processes. 



The endocranium was well ossified from behind the olfac- 

 tory capsules to the occiput. There were distinct exoccipitals 

 and a basioccipital that contributed to the single occipital 

 condyle. The exoccipital was perforated by the hypoglossal 

 foramen and extended forward to the metotic foramen that 

 served nerves IX, X, and XI. A "supraoccipitar' lay above 



nasal 



premoxiMo 



premaxilla 



lacrimal 

 septomoxillq 



nasal 

 septomaxillo 



lacrimal 



maxilla 



frontal 



prefrontal 



postf rental ^ 



parietal foramen 

 jugol 



postorbital 

 intertempora 

 supratemporal 



squamosal 

 quadratojugal 



'quadrate 

 tabular 



postorbital intertemporal 



prefrontol P^^'"!^ ' ' supratemporal 



tabular 



squamosal 



quadrate 

 quadratojugal 



frontal parietal postparietal 



orbitosphenoid \ / 



tabular 

 opisthotic 



orbitosphenoid 



premaxilla 

 vomer 



palatine 



maxilla 

 Pterygoid 

 ectopterygoid 



V2 3 prootic 

 \ i — —y^ — — ,^,_^opisthotic 



fenestra vestJbuli 

 XII 

 exoccipital 



ix-x-xi 



basioccipital 

 parasphenoid 



"supraoccipital" postparietal 



posttemporal fenestra^ ^,,,,-^ — \— , — / — ^.-^ ^tabular 

 parasphenoid 



jugal 



cronioquadrate fissure 

 fenestra vestibul 

 quadratojugal 



quadrate 



Figure 4-24. Skull of Po/oeogyr/nus, on early Pennsylvonian amphibian from Scotland. A, dorsal 

 view with sensory-line system indicated on right half by dashed lines; B, palatal view,- C, lateral view; 

 D, loteral view with bones of cheek removed; E, lateral view with palatoquadrate complex removed; 

 F, rear view. (After Romer) 



OTHER TETRAPODS • 87 



