Vertebral elements lacking hemal spines (Weitzman, 1962), refers generally to the anterior vertebral region bounding the abdominal cavity. Alternate but not quite synonymous terms are abdominal or trunk vertebrae, which bear parapophyses and ribs. In many actinopterygians dorsal to the posterior abdominal cavity there are transitional vertebrae lacking ribs but also without hemal spines or sometimes even enclosed hemal arches. The primary definition would identify these vertebrae as precaudal.(Bird and Mabee, 2003). [ https://doi.org/10.1002/dvdy.10387 ]