part of part of pectoral girdle bone pectoral girdle skeleton dermal bone extracleithrum Narrow bone that lies ventral to the level of insertion of the pectoral fin and is sutured to the posterior edges of both the clavicle and cleithrum. Based on Forey 1998. The presence of this bone is a synapomorphy of coelacanth fishes. UBERON:4200022 T Alexander Dececchi