What the Fossil Record of Dinosaurs Tells Us

Abstract

Dinosaurs were enormously successful animals. They inhabited all seven continents, including polar regions during the Mesozoic. Their temporal range, as currently understood, extends from the Carnian stage of the Late Triassic beginning 228 Ma, to the Maastrichtian stage of the Late Cretaceous, ending 65 Ma. With a temporal span of 163 million years, dinosaurs cannot be judged as failures by puny naked bipeds who have been here for two million years or less and who threaten not only their own existence but that of much of the biosphere. The fossil record of dinosaurs is a complex document that cannot merely be read at face value but which must be carefully evaluated with respect to its inherent biases. There is much we wish to ask about dinosaurs that can only be answered with a mature reliable record. The object of this essay is to discuss some of the factors that impact both on dinosaur diversity itself, and on our understanding of that diversity. While fossils have an objective existence in the rocks, our understanding of their record is the result of a very human process of scientific discovery, subject to the contingencies and biases of history (Dodson, and Dawson, 1991).