basidorsal Basidorsals are bilaterally paired cartilages on the dorsolateral side of the notochord which are replaced by ossified neural arches or dorsal arcocentra. In otophysan fishes, basidorsal 1, bd2, bd3, and bd4 give rise to parts of the Weberian apparatus. TAO:0001060 arcualia teleost_anatomy postcranial axial cartilage