Abstract
The Late Cretaceous Hell Creek Formation, located in Eastern Montana and parts of North and South Dakota, represents a tidally-influenced fluvial environment that was home to a thriving ecosystem 66 million years ago. Today the formation is made of mudstones and sandstones that contain many vertebrate fossil microsites. Microsites are concentrations of fossilized vertebrate bones and teeth ranging in size from fractions of a millimeter to several centimeters. These sites frequently contain many different species of animals and plants, allowing us to paint a picture of what that environment was like in the Late Cretaceous Period. For this study, I collected and analyzed material from a fossil microsite outside the town of Marmarth, North Dakota. Fossil material was collected from the surface of the site, and two five-gallon bulk samples were also collected from the fossil-bearing sediment. The bulk sample material was sieved in a tank of water that was agitated with air from a pump. After sieving, the remaining material was dried and sorted. Fossils were separated from rock in the dried samples using tweezers and a magnifying lamp. Then I worked to identify both the fossils from the bulk sample and fossils collected on the surface of the microsite.
The fossils at this microsite indicate that the area was a shallow stream or river that was home to many different terrestrial and aquatic species. Along with many unidentifiable bone fragments, I identified turtle shell fragments; bony fish scales, teeth and bones; freshwater ray teeth; Champsosaur teeth and teeth of non-avian dinosaurs including Triceratops and Tyrannosaurus. The animals represented at this vertebrate microsite help us better understand diversity in terrestrial environments and how it changed during the end of the Age of Dinosaurs.
College
College of Science & Engineering
Department
Geoscience
Campus
Winona
First Advisor/Mentor
W. Lee Beatty
Start Date
4-19-2023 1:00 PM
End Date
4-19-2023 2:00 PM
Presentation Type
Poster Session
Format of Presentation or Performance
In-Person
Session
2a=1pm-2pm
Poster Number
20
Included in
Characterizing a Vertebrate Microsite in the Late Cretaceous Hell Creek Formation
The Late Cretaceous Hell Creek Formation, located in Eastern Montana and parts of North and South Dakota, represents a tidally-influenced fluvial environment that was home to a thriving ecosystem 66 million years ago. Today the formation is made of mudstones and sandstones that contain many vertebrate fossil microsites. Microsites are concentrations of fossilized vertebrate bones and teeth ranging in size from fractions of a millimeter to several centimeters. These sites frequently contain many different species of animals and plants, allowing us to paint a picture of what that environment was like in the Late Cretaceous Period. For this study, I collected and analyzed material from a fossil microsite outside the town of Marmarth, North Dakota. Fossil material was collected from the surface of the site, and two five-gallon bulk samples were also collected from the fossil-bearing sediment. The bulk sample material was sieved in a tank of water that was agitated with air from a pump. After sieving, the remaining material was dried and sorted. Fossils were separated from rock in the dried samples using tweezers and a magnifying lamp. Then I worked to identify both the fossils from the bulk sample and fossils collected on the surface of the microsite.
The fossils at this microsite indicate that the area was a shallow stream or river that was home to many different terrestrial and aquatic species. Along with many unidentifiable bone fragments, I identified turtle shell fragments; bony fish scales, teeth and bones; freshwater ray teeth; Champsosaur teeth and teeth of non-avian dinosaurs including Triceratops and Tyrannosaurus. The animals represented at this vertebrate microsite help us better understand diversity in terrestrial environments and how it changed during the end of the Age of Dinosaurs.
