Coates is interested in vertebrate evolution, especially the origins of ray-finned fishes, the ancient relatives of the vast majority of fishes swimming the seas today. He co-described Acanthostega, a 360-million-year-old fossil exhibiting characteristics of both fish and amphibians, and has published extensively on the evolution of limbs from fins. Coates studies the deep evolutionary origins of sharks, of which little is known. He also works with molecular biologists to integrate molecular and fossil data, which yield different branching dates in the evolutionary tree of life, and with developmental biologists to understand how fossils inform questions about the evolution of organismal development. His honors include Advanced Research Fellowships from the United Kingdom’s Biotechnology and Biological Sciences Research Council. Coates is co-founder and deputy editor of the journal Evolution and Development.