Fossil Carychiidae (Eupulmonata, Ellobioidea) from the Lower Pleistocene Nashua Formation of Florida, with the description of a new species

Adrienne Jochum; Estée Bochud; David Haberthür; Harry G Lee; Ruslan Hlushchuk; Roger W Portell

doi:10.3897/zookeys.1167.102840

Fossil Carychiidae (Eupulmonata, Ellobioidea) from the Lower Pleistocene Nashua Formation of Florida, with the description of a new species

Zookeys. 2023 Jun 14:1167:89-107. doi: 10.3897/zookeys.1167.102840. eCollection 2023.

Authors

Adrienne Jochum^{1

2

3}, Estée Bochud^{1

2}, David Haberthür², Harry G Lee⁴, Ruslan Hlushchuk², Roger W Portell⁴

Affiliations

¹ Natural History Museum Bern, Bernastrasse 15, CH-3005 Bern, Switzerland.
² Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland.
³ Senckenberg Research Institute and Natural History Museum, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.
⁴ Institute of Anatomy, University of Bern, Baltzerstrasse 2, CH-3012 Bern, Switzerland.

Abstract

Recent fossil shell mining for a new rail line in the Orlando area of Orange County, Florida has uncovered two species of the ellobioid genus Carychium O. F. Müller, 1773 in a bed of freshwater marl from the Lower Pleistocene Nashua Formation. To taxonomically interpret these finds, the well-preserved shells were imaged via high-resolution X-ray tomography (micro-CT) to view significant internal diagnostic characters such as the columellar configuration and the degree of lamellar sinuosity and their relationship in context to the entire shell. The image data are compared to that of type material and extant and fossil Carychium species inhabiting the SE USA, Mexico, Central America, and Jamaica. Based on these results, the species Carychiumfloridanum G. H. Clapp, 1918 and Carychiumnashuaensesp. nov. are identified from fossil shells dating from the Early Pleistocene. This work documents the first fossil members of C.floridanum and the first fossil Carychium from the SE USA.

Keywords: Central Florida; Orlando; Pleistocene; computer tomography; freshwater marl; mollusc assemblage.

Adrienne Jochum, Estée Bochud, David Haberthür, Harry G. Lee, Ruslan Hlushchuk, Roger W. Portell.