DICT.TW Dictionary Taiwan

 het·ero·cer·cal /-ˈsɝkəl/
 歪形尾

 Het·er·o·cer·cal a.  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]