basipterygium

(plural basipterygia))

one of the endochondral fused radials or pterygiophores at the base of a fin, particularly the pelvics. The two chondral basipterygia of the pelvic fin meet anteriorly at the pubic symphysis to form the pelvic girdle. The body of the bone is called the pubic plate and bears an acetabular facet for articulation of the fin rays or the radial bones. An anterior process is known as the pubic process, a middle as the iliac process and a posterior as the ischial process. Also called basalia or pelvic bone. It articulates with the antimere, q.v., the corresponding bone on the opposite side