Name: Heather Smith, PhD -- A revised turtle assemblage from the Upper Cretaceous Menefee Formation, NM
Start: 2026-03-02T19:00:00-07:00
Location: front range community college- Westminster Campus

Heather Smith, PhD -- A revised turtle assemblage from the Upper Cretaceous Menefee Formation, NM

WIPS' March speaker will be Dr. Heather Smith, Professor of Anatomy at Midwestern University, the Editor-in-Chief of The Anatomical Record journal, and a Fellow of the American Association for Anatomy.
Join us in person in Westminster or online via Zoom. Guests are welcome! (If you need the link, message this page or email [email protected] before 3 p.m. on March 2.)
There will be an excellent speaker, refreshments and door prizes!
PROGRAM ABSTRACT: A revised turtle assemblage from the Upper Cretaceous Menefee Formation, NM with evolutionary and paleobiostratigraphic implications
The middle Campanian Menefee Formation (Fm.) of the San Juan Basin of New Mexico is a relatively understudied terrestrial deposit in southern Laramidia preceding the fossil-rich upper Campanian Fruitland and Kirtland formations that have been studied for more than a century. Previous collection efforts have revealed a diverse dinosaurian and crocodyliform fauna in the Menefee Fm., including ankylosaurian, tyrannosaurid, hadrosaurid, ceratopsian, and neosuchian taxa. Nearly a decade has passed since the last description of the Menefee turtle fauna, and we present new material that provides insight into turtle evolution during the Campanian in the Colorado Plateau, with implications for Late Cretaceous turtle paleobiostratigraphy in Laramidia. In particular, we extend the stratigraphic ranges of the baenids Neurankylus baueri and Scabremys ornatabackwards from younger San Juan Basin strata, along with the nanhsiungchelyid Basilemys. Additional material increases Menefee representation of the relict helochelydrid Naomichelys, and the regionally prevalent derived baenids Denazinemys and Thescelus. Additionally, we report new pan-trionychian specimens, which provide insight into the persistence of Adocus and multiple trionychid and plastomenid species through the remainder of the Campanian in the San Juan Basin. A cluster analysis of turtle diversity across early-middle Campanian sites in Laramidia shows distributions consistent with latitudinal provinciality in some groups. For instance, derived baenids were restricted to latitudes south of southern Utah, along with marine taxa (bothremydids and protostegids) and pan-kinosternoids. Basin-scale endemism is also suggested by some baenid and trionychid distributions. Otherwise, the turtle fauna of the Menefee most closely resembles those of the similarly-aged Wahweap Fm. in southern Utah, and the Aguja Fm. in the Big Bend area of Texas and Mexico to a lesser extent. The Menefee turtle assemblage is consistent with reconstructed paleoenvironments characteristic of the western shoreline of the Western Interior Seaway. Recurrent cyclothems in these settings shaped the development of fluviodeltaic deposits that preserved distal components of large channels with surrounding floodplains and swamps, along with evidence of freshwater, brackish, and possibly shallow marine influence. This research was funded by a grant from WIPS.
ABOUT THE SPEAKER:
Dr. Heather Smith is a Professor of Anatomy at Midwestern University, the Editor-in-Chief of The Anatomical Record journal, and a Fellow of the American Association for Anatomy. She earned a B.A. in Anthropology (Arizona State University’s Barrett Honors College, 2001), M.A. in Biological Anthropology (Stony Brook University, 2003), a Ph.D. in Biological Anthropology (Arizona State University, 2008), and completed her postdoctoral training at the University of Arizona’s College of Medicine, Phoenix (2009). She is an evolutionary biologist, comparative anatomist, and paleontologist. Her research combines both living species and the fossil record, with a special interest in ancient turtles, to reveal how bones and body structures evolved through millions of years. In particular, she investigates how cranial and shell morphology evolved across extinct and living turtle species using 3-D geometric morphometrics and other tools to trace phylogeny, adaptation, and developmental change.
Dr. Smith has been conducting paleontological fieldwork and research since 2012, primarily focusing on North American Late Cretaceous and Paleogene turtles, and has been involved in the descriptions of 4 new species of fossil turtle. Since 2024, she has been a founding co-director of the Menefee Paleontological Project, coordinating paleo fieldwork in the Campanian Menefee Formation of New Mexico.