THE ICHNOLOGICAL AND DEPOSITIONAL CONTEXT OF BIOERODED TRICERATOPS BONES FROM THE MAASTRICTHIAN FRENCHMAN FORMATION OF SOUTHERN SASKATCHEWAN, CANADA
Date
2024-06-28
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Thesis
Degree Level
Masters
Abstract
Previous studies on osteic bioerosion trace fossils on dinosaur bones have contributed to our understanding of Mesozoic terrestrial paleoecology and depositional environments. In many cases, body fossils of the inferred tracemaker are either exceedingly rare or absent from the fossil record due to taphonomy. However, studies of bioerosion on dinosaur material conducted on Canadian specimens are uncommon, which is surprising given the volume of dinosaur material collected each year in the country. The ceratopsid Triceratops prorsus is the most common dinosaur fossil from the latest Maastrichtian Frenchman Formation in Saskatchewan, represented by thousands of specimens. Classifying osteic bioerosion trace fossils on Triceratops bones from the Frenchman Formation using established ichnotaxobases coupled with sedimentological data allows for insight into the hidden invertebrate diversity within the Frenchman Formation, as well as how plants used dinosaur bones as a nutrient source.
Stratigraphic sections of the Frenchman Formation were measured in four localities containing Triceratops specimens. All bioeroded specimens of Triceratops identified were preserved in organic-rich mudstone and siltstone deposits, representing floodplain paleosols. Soils are the ideal habitat for terrestrial invertebrate scavengers that serve as the decomposers of decaying animal matter during the early dry stages of decay. The large ichnodiversity of osteic bioerosion trace fossils preserved in Triceratops bones from the Frenchman Formation are the result of pupation chamber construction and necrophagous, and possibly osteophagous terrestrial invertebrates, likely beetles based on comparisons of extant carrion beetle behaviour. Rhizoetchings on bone can be attributed to ancient plant roots directly associated with the Triceratops bones. Established plant communities that utilize soils therefore have a significant ichnological footprint on post-mortem Triceratops bones following burial. Different degrees of preservation of Triceratops bones within floodplain and overbank deposits including poorly drained or water-logged paleosols indicate different taphonomic pathways. This thesis serves as a template for future taphonomic studies of vertebrate body fossils material, considering sedimentological and ichnological evidence on the bones.
Description
Keywords
Bioerosion, Ichnology, Triceratops, Dinosaur, Taphonomy, Insects, Plants, Sedimentology, Saskatchewan
Citation
Degree
Master of Science (M.Sc.)
Department
Geological Sciences
Program
Geology