Abstract: The allometric analysis of juvenile and adult shells of late Carboniferous and
Permian ammonoids reveals a different frequency of shell types.  The investigated Carbonife-
rous shells are comparatively uniform, whereas the Permiam ones exhibit a considerable in-
crease in shell diversity.  The aim of the present research is the investigation of the changes in
the distribution pattern of the different ammonoid shell types during Paleozoic times.