part of overlaps develops from start stage end stage pelvic girdle basipterygium zebrafish_anatomy ZFA:0000623 pelvic bone TAO:0000623 pelvic girdle Endochondral bone that is paired and supports the pelvic fin. The basipterygium has a posteromedial process called the ischiac process (Wietzman 1962). basipterygium cartilage endochondral bone inter-basipterygium joint unknown adult