Turtles From an Arkadelphia Formation—Midway Group Lag Deposit (Maastrichtian—Paleocene), Hot Spring County, Arkansas, USA
The Arkadelphia Formation—Midway Group (Maastrichtian—Paleocene) contact near Malvern, Arkansas preserves a K-Pg boundary assemblage of turtle species consisting of skull, shell, and non-shell postcranial skeletal elements. The Malvern turtles are preserved within a coquina lag deposit that comprises the basalmost Midway Group and also contains an abundance of other reptiles, as well as chondrichthyans, osteichthyans, and invertebrates. This coquina lag deposit records a complex taphonomic history of exhumation and reburial of vertebrate skeletal elements along a dynamic ancestral shoreline in southwestern Arkansas during the late Cretaceous-early Paleocene. Based on stratigraphic occurrence, the Malvern turtle assemblage indicates that these marine reptiles were living at or near the time of the K-Pg mass extinction and represent some of the latest Cretaceous turtles yet recovered from the Gulf Coastal Plain of the United States.
This article originally appeared in Geosciences, available at DOI: 10.3390/geosciences6030041
© 2016 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).