New records of temperate mollusks in two Late Pleistocene terrestrial localities from northeastern Oaxaca, Southern Mexico

- This assemblage is the first Late Pleistocene faunule reported in southern Mexico.
- These records are the last appearance data of these taxa in Coixtlahuaca region.
- Paralaoma vitreum represents the first record in the Late Pleistocene.
- Identified species are indicative of several water bodies, as opposite as nowadays.
- Biogeographic affinity of taxa is with species of temperate zones, mainly holartic.

The Mixteca Alta Oaxaqueña is in the state of Oaxaca, southern Mexico. This region is characterized by numerous Pleistocene fossiliferous localities. The objective of this study is to describe a diverse assemblage of Late Pleistocene freshwater and terrestrial mollusks in two localities from northeastern Oaxaca, Coixtlahuaca District. We identified 10 taxa of gastropods and one of bivalves. By the sedimentological characteristics and the mollusks assemblage, it is possible to relate the first locality with meandriform river deposits, without vegetation. The second locality was associated with a floodplain with short-lived associated vegetation. Five identified species constitute the most austral records of these taxa in Neartic Realm. In all the taxa, the Late Pleistocene occurrences constitute the last records of the identified mollusks in the study zone.