Skip to Main Content

Paleoecology of the Gaddis Site in the Upper Cretaceous Aguja Formation, Terlingua, Texas

Homer Montgomery and Scott Clark
Paleoecology of the Gaddis Site in the Upper Cretaceous Aguja Formation, Terlingua, Texas
Palaios (July 2016) 31 (7): 347-357


Diverse faunas at the Gaddis site near Terlingua, Texas are present at four stratigraphic levels along a hill in the Upper Cretaceous Aguja Formation providing a rich fossil record of the transition from an aquatic environment to dry land while recording exceptional events such as predation and wildfires. Given evidence for minimal transport the microvertebrates, macrovertebrates, coprolites, and plants may be reliably utilized for paleoecological analysis. Paleoenvironments shift upsection from nearshore marine, through tidal channel, to swamp, and, finally, to well-vegetated dry land. The faunas change from a basal layer of oysters with shark teeth to a microvertebrate assemblage just above logs with Teredolites borings and pristine leaves. Above the microvertebrates are diverse macrovertebrates including numerous dinosaurs associated with leaves, logs, and scrambling vines. The macrovertebrate layer is a rich assemblage of herbivorous and carnivorous dinosaurs, crocodiles, turtles, and rare pterosaurs. Several skeletal elements exhibit signs of predation that include punctures and gouges that precisely match crocodile and theropod teeth also recovered at the site. Abundant plant material that includes charred vines and logs is likely evidence of wildfires having ranged across the area. The preponderance of young dinosaur remains may support a wildfire scenario. An exposed surface with 24 coprolites, two hadrosaur vertebrae, logs, and in situ stumps caps the section. The larger coprolites are likely dinosaurian. Most contain plant materials while one contains a bone fragments suggesting the presence of herbivorous and carnivorous dinosaurs on the same surface, an occurrence that echoes herbivore/carnivore interactions in the underlying bonebed.

ISSN: 0883-1351
Serial Title: Palaios
Serial Volume: 31
Serial Issue: 7
Title: Paleoecology of the Gaddis Site in the Upper Cretaceous Aguja Formation, Terlingua, Texas
Affiliation: University of Texas at Dallas, Department of Science and Mathematics Education, Richardson, TX, United States
Pages: 347-357
Published: 201607
Text Language: English
Publisher: Society for Sedimentary Geology, Tulsa, OK, United States
References: 71
Accession Number: 2016-083595
Categories: Stratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. strat. col., 3 tables, sketch map
N29°19'60" - N29°19'60", W103°39'00" - W103°39'00"
Secondary Affiliation: West Texas Science Center, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by SEPM (Society for Sedimentary Geology), Tulsa, OK, United States
Update Code: 201640
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal