Examination of the foregut and gastric mill of individuals sacrificed
directly prior tomolting indicated that the newmedial tooth and lateral
teeth are formed during the premolt period (Fig. 1b). The new medial
tooth forms in the cavity between the current medial tooth and the
propyloric ossicle. The new lateral teeth form laterally to the current
teeth, but outside of the inner cuticular layer of the foregut that is
shed at molting (Fig. 1c). Newaccessory teeth (described as the dentate
on the inner side of the pectineal ossicle in Maynard and Dando, 1974)
are also formed premolt. At this stage these new teeth are soft and can
be easily compressed with forceps, in comparison with the rigidity of
the old teeth. There was no evidence to suggest the de-calcification of
the gastricmill ossicles prior tomolting, but cracks between the old lateral
teeth plates and the zygocardiac ossicles where they separate at
molting were visible (Fig. 1b). The paired gastroliths on the lateral
walls of the cardiac foregutwere also present in all individuals sacrificed
premolt.