Waves and shallow water

Ecology

Fauna

Geography

Bathyal zone

Geology

Temperate climate

Biology

Oceanography

Latitude

Paleontology

Benthic zone

Geodesy

Equator

Nature

Our knowledge of the distribution and evolution of deep-sea life is limited, impeding our ability to identify priority areas for conservation1. Here we analyse large integrated phylogenomic and distributional datasets of seafloor fauna from the sea surface to the abyss and from equator to pole of the Southern Hemisphere for an entire class of invertebrates (Ophiuroidea). We find that latitudinal diversity gradients are assembled through contrasting evolutionary processes for shallow (0–200&nbsp;m) and deep (&gt;200&nbsp;m) seas. The shallow-water tropical–temperate realm broadly reflects a tropical diversification-driven process that shows exchange of lineages in both directions. Diversification rates are reversed for the realm that contains the deep sea and Antarctica; the diversification rates are highest at polar and lowest at tropical latitudes, and net exchange occurs from high to low latitudes. The tropical upper bathyal (200–700&nbsp;m deep), with its rich ancient phylodiversity, is characterized by re...

Contrasting processes drive ophiuroid phylodiversity across shallow and deep seafloors