The Permian Ammonoid Family Medlicottiidae in the Verkhoyansk Region

Representatives of the family Medlicottiidae (Ammonoidea) from the Permian of the Verkhoyansk Region are revised. Medlicottiids in the region are represented only by the subfamily Uddenitinae and are only known from four stratigraphic levels in the Lower Permian. Prouddenites evolutus sp. nov., representing the terminal phase of the morphogenetic development of the genus Prouddenites is found near the base of the Asselian (lower part of the Khorokyt Formation). A fragment of the body chamber of a representative of the Uddenitinae with no certain generic affinity was found in the Uraloceras subsimense Beds of the Sakmarian Stage (Lower Echij Subformation). Representatives of the species Neouddenites echiensis sp. nov., the most primitive known Neouddenites species, were found in the Upper Echij Subformation of the Artinskian Stage. Most medlicottiid occurrences (Neouddenites andrianovi Ruzhencev, 1961) were from the lower part of the Tumarian Regional Stage (Orol Formation) of the Kungurian Stage. The origin of the genus Neouddenites from Prouddenites is suggested. Two new species of Medlicottiidae (P. evolutus and N. echiensis) are described.