Stratigraphy and dinosaur palaeontology of the Wealden Group, Isle of Wight

The Wealden Group of the Isle of Wight comprises fluvial and shallow marine strata deposited during the Early Cretaceous. The floodplains and beaches of the Wealden were home to a diversity of dinosaurs including the armoured ankylosaurs, the fish-eating spinosaurs, and the thumb-spiked iguanodontians. The Wealden dinosaurs are the best-known and most diverse from any time period in the UK.

In contrast, the sediments have not been studied in the context of modern techniques and analyses. Consequently, depositional environments are poorly characterized, and a detailed chronostratigraphy is lacking. This hinders attempts to understand the evolution and palaeoecology of the dinosaurs, because they cannot be placed accurately in time, and the environments in which they lived and died are not always clear.

The aim of this project is to examine the relationships between the occurrence of dinosaur remains, sedimentary facies, and chronostratigraphy in the Wealden of the Isle of Wight. The working conceptual model of the depositional setting for the Wealden Group is a river system that was not confined to a valley, and to significant marine influence. Through the Wealden Group, sedimentary facies indicate that the river system was gradually flooded by a rising sea level.

It is this conceptual model that we look to test; we will examine whether patterns of sea level fluctuation and a tendency of increased marine influence can be recognised upwards through the succession. Such studies will be carried out through facies analysis of fluvial elements across the island. The culmination of this work will be the first chronostratigraphic framework for the Isle of Wight Wealden.

We will then locate dinosaur occurrences across the island and discover if certain taxa can be correlated to a depositional sequence, hence palaeoenvironmental setting. Such insights will allow us to examine preservational biases in the fossil record that might be hindering our understanding of dinosaur diversity and distribution and predict possible future sites.

Finally, we will map dinosaur occurrences onto our chronostratigraphic framework and attempt to assess whether specific dinosaurs were isolated to specific timeslices, to characterize dinosaur evolution and inform analyses of dinosaur taxonomy and diversity.