LAUSR

Coastal habitats represent a cradle of diversification for early vertebrates Vertebrates encompass all animals with a backbone, from fish to humans. How and when they evolved are questions that have been studied for centuries, revealing the origins and processes involved in anatomical innovations such as jaws, teeth, and paired appendages (1). A less explored, but equally important question is where they evolved. On page 460 of this issue, Sallan et al. (2) compile a new database of early occurrences (mid-Paleozoic, 490 to 360 million years ago) and site-specific environmental information to reconstruct vertebrate ancestral habitats. They report that all major vertebrate clades originated in restricted, shallow-water environments.