Data from: The nearshore cradle of early vertebrate diversification

Ancestral vertebrate habitats are subject to controversy and obscured by
limited, often contradictory paleontological data. We assembled fossil
vertebrate occurrence and habitat datasets spanning the middle Paleozoic
(480 million to 360 million years ago) and found that early vertebrate
clades, both jawed and jawless, originated in restricted, shallow
intertidal-subtidal environments. Nearshore divergences gave rise to body
plans with different dispersal abilities: Robust fishes shifted shoreward,
whereas gracile groups moved seaward. Fresh waters were invaded
repeatedly, but movement to deeper waters was contingent upon form and
short-lived until the later Devonian. Our results contrast with the
onshore-offshore trends, reef-centered diversification, and mid-shelf
clustering observed for benthic invertebrates. Nearshore origins for
vertebrates may be linked to the demands of their mobility and may have
influenced the structure of their early fossil record and diversification.