Abstract
Twenty-three species of Campanian, Maastrichtian, Paleocene, and Eocene freshwater gastropods from northeastern Mexico are described, including eight new species:Viviparus mcbridei, Pachychilus(Pachychiloides)lawtoni, Melanoides(Melanoides)yolandae, Melanoides(Melanoides)wollebeni, Physa cepedaensis, Mesolanistes magnus, Mesolanistes murrayi, andGyraulus zoltani.Specimens were collected from fine-grained, green sandstone and mudstone, red mudstone, and as hematized remains in fine light-brown sandstones belonging to the following stratigraphic units of northeastern Mexico: Cerro del Pueblo (Campanian, Parras Basin), Olmos (Maastrichtian, Sabinas Basin), Las Encinas (Paleocene, Parras Basin), and Carroza (Eocene, La Popa Basin) Formations. All except two of the genera (?PyrguliferaandMesolanistes) have recent representatives. Review of habitats of living species of the six extant genera and interpretations of sample lithologies support the inference of dominantly freshwater paleoenvironments. Only one Maastrichtian locality is interpreted confidently to have had a brackish water influence.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
