INNER WHORLS OF GREGORYCERAS (AMMONITINA, PELTOCERATINAE) AS THE FIRST OCCURRENCE OF THE GENUS IN MEXICO

Abstract

Two nuclei of Gregoryceras are described as the first record of the genus in Mexico. The occurrence in Mexico of the ubiquitous Tethyan genus Gregoryceras is interpreted as related to a major flooding episode that affected neritic shelves in the southern North-American plate.