basal fulcrum epaxial basal fulcrum Basal fulcrum that is positioned at the dorsal or anterodorsal margin of the caudal fin. Arratia, G. 2009. Identifying patterns of diversity of the actinopterygian fulcra. Acta Zoologica (Stockholm) 90 (Suppl. 1): 220-235. TAO:0002292 dorsal basal fulcra dorsal basal fulcrum epaxial basal fulcra teleost_anatomy