Submission Type
Poster
Abstract
The Tarrant Formation (middle Cenomanian: ca. 96 million years ago) is a stratigraphic member of the Upper Cretaceous Eagle Ford Group in Texas, U.S.A., and consists of calcareous sandstone formed near the East Texas Embayment of the Late Cretaceous Western Interior Seaway, an epicontinental seaway in North America. We examined vertebrate fossils from the Tarrant Formation based on specimens collected through surface collecting and bulk sampling from three localities in Tarrant County, Texas, including the type locality of a pachyrhizodontid fish, Polcynichthys lloydhilli. Our preliminary examination shows that the fossil fauna includes shark species such as Ptychodus anonymous, Archaeolamna sp., Cretoxyrhina mantelli, Cretodus sp., Squalicorax cf. S. falcatus, S. cf. S. pawpawensis, multiple types of bony fishes, such as Enchodus gladiolus, and Pachrhizodus minimus, and a squamate, Coniasaurus sp. The identified shark taxa consist of durophagous (Ptychodus) and scavenging (Squalicorax) forms as well as large predatory forms (Cretoxyrhina and Cretodus) that likely fed primarily on other vertebrates, such as bony fishes. This study is significant because the Tarrant Formation fauna provides additional insight into the marine paleoecology during the early developmental phase of the Western Interior Seaway.
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Late Cretaceous marine vertebrates from the Tarrant Formation, Tarrant County, Texas U.S.A
The Tarrant Formation (middle Cenomanian: ca. 96 million years ago) is a stratigraphic member of the Upper Cretaceous Eagle Ford Group in Texas, U.S.A., and consists of calcareous sandstone formed near the East Texas Embayment of the Late Cretaceous Western Interior Seaway, an epicontinental seaway in North America. We examined vertebrate fossils from the Tarrant Formation based on specimens collected through surface collecting and bulk sampling from three localities in Tarrant County, Texas, including the type locality of a pachyrhizodontid fish, Polcynichthys lloydhilli. Our preliminary examination shows that the fossil fauna includes shark species such as Ptychodus anonymous, Archaeolamna sp., Cretoxyrhina mantelli, Cretodus sp., Squalicorax cf. S. falcatus, S. cf. S. pawpawensis, multiple types of bony fishes, such as Enchodus gladiolus, and Pachrhizodus minimus, and a squamate, Coniasaurus sp. The identified shark taxa consist of durophagous (Ptychodus) and scavenging (Squalicorax) forms as well as large predatory forms (Cretoxyrhina and Cretodus) that likely fed primarily on other vertebrates, such as bony fishes. This study is significant because the Tarrant Formation fauna provides additional insight into the marine paleoecology during the early developmental phase of the Western Interior Seaway.
