Species richness and endemism of all described ophiuroids across 12 a priori defined regions and four depth strata.

The area of each region/depth strata was calculated from the ETOPO bathymetric dataset (Amante & Eakins 2008).# A few species were described from specimens without known sample locality or depth information.*As species can occur in more than one region and depth stratum, the total species counts are not a simple arithmetic sum of regional species richness.