Abstract

The evolution of animals was one of the most important biological events in the history of life on Earth, not only because it paved the way for our own existence, but because animals have had an enormous and irreversible impact on our biosphere. In recent years, the focus of studies into the initial evolution and radiation of animals has centred on the fossil record of the late Ediacaran Period, which documents diverse communities of unusual organisms that lived between 580 and 541 million years ago. As a Henslow Junior Research Fellow, I have investigated some of the oldest localities of these Ediacaran fossils, and my findings have played a significant role in advancing our understanding of both what these organisms were, and the dynamics of Ediacaran ecosystems. In particular, the discovery of probable cnidarians within these assemblages, and of locomotion trackways created by similar organisms, provides the first strong evidence that animals were present around 565 million years ago. This knowledge permits us to tackle more substantial evolutionary questions regarding how and why animal evolution took place at this particular point in time.