A new species of Lysinoe (Gastropoda: Helicoidea) from the Oligocene of Mexico

Abstract

In her 1945 study on the Tertiary fossil mollusks of northeastern Mexico, Gardner listed only 2 taxa of land snails: Holospira eva Gardner, 1945 and “Helix” sp. The latter is recognized here as a new species of Lysinoe Adams & Adams, 1855 (Helicoidea, Xanthonychidae). The new species can be diagnosed from its congeners by its flattened shell profile, a lower body whorl with a faint angulation on its median portion, a ridge-like angulation around the umbilicus, and a likely wide umbilicus. The species is known to occur in 2 nearby Upper Middle Oligocene outcrops in the eastern part of the state of Nuevo León.