Abstract.  Taxonomic revision in relation to occurrence ranges within international subdivisions for
the Permian System enables recognition of multi-episodal extinction patterns for ammonoid
cephalopods.  These can be related to the overall transgressive/regressive eustasy curves of the
second order Transpecos Supercycle and to its component third-Order cycles.  Transgressions that
followed successive regressions spread restricted epicontinental seas, and resulted in diversification
of short-ranged endemic ammonoid genera.  Contrary to recent assertions, the extinction event at
the end of the upper Guadalupian (Maokouan) Capitanian Stage was comparable to those that
characterize other Permian stages, and not to the mass extinction that terminated the uppermost
Permian Changhsingian Stage and coincident Paleozoic Erathem.