What is "heterocercal"

Heterocercal \Het`er*o*cer"cal\, a. [Hetero- + Gr. ? tail.] (Anat.) Having the vertebral column evidently continued into the upper lobe of the tail, which is usually longer than the lower one, as in sharks.

a. (context ichthyology English) Of a fish's tail, such that the vertebral column bends and extends upwards into the upper lobe of the tail, making it larger than the lower lobe; as in sharks, rays, and skates.

adj. possessing a tail with the upper lobe larger than the lower and with the vertebral column prolonged into the upper lobe [ant: homocercal]