Geological Society of America

9 Undergraduate Research (Posters)

Monday, 10 March 2025
8:30 AM - 5:00 PM
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DESCRIPTION OF NON-DINOSAURIAN MATERIAL FROM THE SITE OF THE MOST COMPLETE DINOSAUR THUS FAR DISCOVERED IN MISSISSIPPI, FROM THE COFFEE FORMATION (EARLY/MID-CAMPANIAN)

Paper number: 9-3
Program: Theme Sessions
Time: 8:30 AM – 5:00 PM

Authors

Keishawn Smith Presenting Author
School of Biological, Environmental and Earth Sciences, Hattiesburg, MS
Derek Hoffman
University of Southern Mississippi, Hattiesburg, MS
Alyson Brink
University of Southern Mississippi, Hattiesburg, MS
George E. Phillips
Mississippi Museum of Natural Science, Jackson, MS
James Starnes
Office of Geology, Jackson, MS
Nina Baghai-Riding
Delta State University, Cleveland, MS
Carol Hotton
National Museum of Natural History,, Washington, MS
Olivia Pharr
Delta State University, Cleveland, MS
Dave Hanes
Columbia, SC

Abstract

The Coffee Sand is a shallow-marine to transitional sand unit of the Upper Cretaceous Selma group. It outcrops in northeastern Mississippi and southwestern Tennessee and is well known for its extensive molluscan fossil diversity. The Coffee Sand can be broken up into a sandy upper section, known as the Tupelo Tongue, a clay rich lower section. The interpreted depositional environments of the Coffee Sand include lagoons, barrier islands, offshore bars, and surge channel deposits. The Booneville Dinosaur Site, an outcrop of the lower Coffee Sand, is the location of the most complete dinosaur discovered thus far in Mississippi. In addition to its completeness, this dinosaur is significant as the first member of its family to be discovered in a paralic depositional environment within southern Appalachia. Here we present a complete faunal list of the Booneville Dinosaur Site including all vertebrates, invertebrates, and palynoflora. We also compare it to other known Coffee Sand localities which adds more context and significance to the paleoenvironmental interpretation.

A recent palynological assessment coupled with the presence of alternating layers of organic rich clay and flaser to wavy bedded sands indicate an intertidal estuarine to deltaic environment. Vertebrates include sharks, turtles, and crocodilians, while invertebrates include indeterminate gastropods and decapods, bivalves Trachycardium and Pterotrigonia, and ammonites Placenticeras and Menabites, alongside various ichnofossils. Ammonites are very common in the layer the dinosaur was found in, although the largest ammonite fragments have been recorded in the Pterotrigonia bed. The vertebrates, invertebrates, and palynoflora present suggest the Booneville Dinosaur Site is similar to other documented Coffee Sand localities and supports the previous interpretation of the BDS as an intertidal estuarine to deltaic environment.

Geological Society of America Abstracts with Programs. Vol. 57, No. 1

doi: 10.1130/abs/2025SC-409023

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