Paleoenvironments and paleoecology of the Cenomanian Woodbine Formation of Texas: Paleobiogeography of the hadrosaurs (Dinosauria: Ornithischia).

摘要

The goal of this project was to analyze the fossils recovered from a series of sites in the Woodbine Formation of Texas, place them into a paleoenvironmental context and a paleobiogeographic framework. This study was conducted to gain an understanding of Cretaceous paleoecology and biogeography in relation to paleogeographic change. To facilitate this, a facies analysis of the Woodbine was conducted to understand the environments that preserve these fossils. Stratigraphic sections of Woodbine exposures were measured in at Lake Grapevine and in Arlington. The Lake Grapevine sections represent a Mississippi style, or a fluvial delta sequence. The Arlington Archosaur site is a fluvial channel fill sequence. The sections are interpreted as a Gyttja style channel fill. Archosaur fossils were recovered from each study area where sections were measured.; The biogeographic distribution of the hadrosaurids was modeled with a series of G.I.S. maps. A series of maps was developed using ArcMap and Plate Tracker, From these, a series of maps was developed to illustrate the distributions of hadrosaurs. Once hadrosaurs established communities in North America, their fossil record shows distinct biogeographic provinces. The northern province had the most diverse fauna. Of these, Edmontosaurus was the most common. The southern province was composed of a smaller fauna, the oldest was Protohadros.; Eurasian hadrosaurian biogeography was not as diverse as that of North America, however the fauna is unique to the continent. Mid-Cretaceous Eurasian faunas are distinct in their composition with the earliest forms: Equijubus, Probactrosaurus, Bactrosaurus and Gilmoreosaurus . (Abstract shortened by UMI.)