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