part of part of overlaps overlaps pelvic region element pelvic girdle skeleton endochondral element inter-basipterygium joint basipterygium element pubic plate UBERON:2100623 basipterygia basipterygium pelvic bone os pelvien pelvic plate basiptrygium ischiatique Endochondral element that is paired and supports the pelvic fin. The basipterygium has a posteromedial process called the ischiac process (Wietzman 1962).