The ‘Tail’ of the Male American Toad, Ascaphus

Abstract

Ascaphus (North America) and Liopelma (New Zealand) constitute, according to Dr. G. K. Noble, the Liopelmidæ, the most primitive anuran family in existence. Apart from the importance of Ascaphus from the general phylogenetic aspect, it has often been credited with possessing a tail. Noble has described a pair of tail-wagging muscles for the genus. Moreover, Ascaphus possesses a prepelvic skeletal structure of the nature of a prepubis (or epipubis) and is further notorious in possessing post-pelvic ‘Nobelian cartilages’ (Mehelij). Presumably the epipubis and the Nobelian cartilages represent chondrifications of the pre- and post-pelvic portions of the linea alba respectively. The latter are known in Ascaphus only.