Hĕt'er-o-çẽr'cal, a.

adjective

a. [Gr. ἕτερος, other, and κέρκος, tail.] (Compar. Anat.) Having the vertebral column continued into the upper lobe of the tail, which, on this account, is larger than the lower;—said of certain species of fish. Agassiz.

A diagram of a heterocercal shark's tail.
Heterocercal (shark's tail).