Inguinal Amplexus in Bufo fastidiosas , with Comments on the Systematics of Bufonid Frogs

outgroup comparison, it would be interesting to find pleurodont tooth attachment in the hatchling second and third generation teeth. Such was not the case, however, except perhaps for the premaxillary teeth (of which there are three on each side), where the distinction of pleurodonty and acrodonty becomes somewhat blurred. Harrison (1901, 1901-1902) noted a variable and vestigial vomerine dentition, starting its development towards the end of the incubation period. In the hatchling here described, one single vomerine tooth could be observed on the left element, none on the right bone. The maxillary and dentary show the typical second and third generation dentition as described by Harrison (1901, 1901-1902), with teeth of alternating size following the two anteriormost teeth. The smaller teeth are positioned slightly laterally (labially) of the larger teeth and show signs of erosion at their base providing space for the accommodation of the larger teeth as these move up in a linguo-labial (medio-lateral) direction to line up in between the smaller teeth. The posteroventral base of the larger teeth typically overlap the anteroventral base of the following smaller tooth at this early stage of development. This confirms the conclusion drawn by Harrison (1901) and Edmund (1960) that the teeth of alternating size represent two different generations, with the smaller teeth representing the second, the larger teeth representing the third generation. Whiteside (1986) reached an opposite conclusion based on fully developed fossil material, conveying the impression that the smaller teeth are positioned lingually with reference to the larger teeth.