irregular bones are anemestics. The operculum differs in 

 having three posterior marginal gulars rather than a single 

 unit. Much of the endocranium is as yet unknown but was 

 probably divided into two divisions. 



Coelacanfh or acfinistian crossopferygian The coelacanths 

 are the best known of the crossopterygians because of the 

 living species, Latimeria chalumnae (Figures 4-33, 4-34). The 

 earliest fossil coelacanth, which is at least partly known, is 



posterior openings of 

 rostral organ 



lateral rostral, 



anterior opening 

 of rostral organ. 



internal nasal opening'' 

 lateral ethmoid 

 autopalotine articulation' 



otic branches of VII 



superficial ophthalmic Vll 

 anterior cerebral artery 

 and vein 



extrascopular series 

 tabular 



internal carotid 



pituitary vein 



notoch 



prootic 

 tooth plate 

 anterior basioccipital 



posttemporol 

 supraoccipitol 



exoccipital 

 lateral canal 



basioccipital 



articular sockets for hyomandibula 

 on lateral commissure 



supratemporal 



extrascapulors 



orbitonasal artery 

 orbitonasal foramen V 

 nasal series 

 posterior external 



nasal openjn 



anterior external 



nasal opening' 



tabular 

 7/V. posttemporol 



supraoccipitol 



hyomandibular branch Vll 

 hyomandibula 



B 



perilymphatic canal 

 IX 



exoccipital 

 occipitospinal foramina 



prootic 



ental 



retroarticular process 



spienial 



Figure 4-34. The endocranium and jaws of Latimerio. A, lateral view of endocranium; B, lateral 

 view of head skeleton (without branchial arches}; C, medial view of mandible. (After Mi I lot 

 and Anthony, 1958) 



98 • HEAD SKELETON OF OTHER TETRAPODS AND CHOANATES 



