Lizard Caudal Vertebrae

Abstract

tion with regard to the presence or number, shape, size, and orientation of the transverse processes and their positional relationship to the autotomic planes of fracture. Individual caudal vertebrae may bear one or two pairs of transverse processes or may lack them. The plane of fracture may pass in front of, through, or behind the processes when one pair is present, and passes between the anterior and posterior pairs when two are present. A single pair of processes may be oriented anterolaterally, laterally, or posterolaterally, and paired processes may converge or diverge distally. Sequential change in the caudal vertebrae from sacrum to tail tip is gradual and involves relatively slight modifications in some lizards, but is more often abrupt, takes place within the space of two or three vertebrae, and involves relatively major changes such as the loss or doubling of proc-