epural

adj

1. On the dorsal side of the tail.

   “The opercular bone is reduced and the suboperculum enlarged, and the caudal skeleton is unique in having only two free epural bones, with the third, anteriormost one fused to the second preural centrum.”

noun

1. A boney or cartilaginous neural spine on the epural side of a fish's axial column, sometimes supporting fin-rays.

   “Presence of two epurals is the more likely derived condition for stomiiforms based on functional outgroup comparison to Diplophos and Manducus.”