Bissett Formation
Encyclopedia
The Bissett Formation is a Mesozoic
geologic formation. Dinosaur
remains diagnostic to the genus
level are among the fossils that have been recovered from the formation.
The Bissett was first mapped and named by Philip B. King in 1927. King's stratigraphic reckoning described the Bissett as a Permian deposition.
E.C. Case changed the age determination in the 1930's to Triassic based on a photo of what he believed to be a fossil fragment of a desmatosuchus.
The Bissett comprises several types of sedimentary deposition, a conglomerate with Permian limestone cobbles, a sandstone sequence, red beds, and lacustrine limestone. It was in the limestone beds that fossil remains of the iquanadon were found (Wilcox, 1989)
The Iquanadon remains were positively identified by Dr. Wann Langston at the University of Texas Bureau of Economic Geology Vertebrate Paleontology Lab in Austin. Other diagnostic fossils were also found during this effort in the same limestone outcrop, including conifers and bivalves.
The fossil discoveries positively place the age of the Bissett formation as early Cretaceous, approximately 115 million years ago.
conifers - frenelopsis sp. or pseudofrenelopsis sp.
carophytes - Atopochara trivolvis and Clavator harrisi
non-marine pelecypod - Protolliptio douglassi
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
geologic formation. Dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
remains diagnostic to the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
level are among the fossils that have been recovered from the formation.
The Bissett was first mapped and named by Philip B. King in 1927. King's stratigraphic reckoning described the Bissett as a Permian deposition.
E.C. Case changed the age determination in the 1930's to Triassic based on a photo of what he believed to be a fossil fragment of a desmatosuchus.
The Bissett comprises several types of sedimentary deposition, a conglomerate with Permian limestone cobbles, a sandstone sequence, red beds, and lacustrine limestone. It was in the limestone beds that fossil remains of the iquanadon were found (Wilcox, 1989)
The Iquanadon remains were positively identified by Dr. Wann Langston at the University of Texas Bureau of Economic Geology Vertebrate Paleontology Lab in Austin. Other diagnostic fossils were also found during this effort in the same limestone outcrop, including conifers and bivalves.
The fossil discoveries positively place the age of the Bissett formation as early Cretaceous, approximately 115 million years ago.
Paleofauna
- cf. Iguanodon sp.
conifers - frenelopsis sp. or pseudofrenelopsis sp.
carophytes - Atopochara trivolvis and Clavator harrisi
non-marine pelecypod - Protolliptio douglassi