<p>The distribution of all known Cambrian echinoderm taxa, encompassing both articulated specimens and taxonomically diagnostic
isolated ossicles, is documented for the first time. The database described by 2011 comprises 188 species recorded from 65
formations from around the world. Formations that have yielded articulated echinoderms are unequally distributed in space
and time. Only Laurentia and West Gondwana provide reasonably complete records at the resolution of Stage. The review of the
biogeographical distributions of the eight major echinoderm clades shows that faunas from Laurentia and Northeast Gondwana
(China and Korea) are distinct from those of West Gondwana and Southeast Gondwana (Australia); other regions are too poorly
sampled to make firm palaeobiogeographical statements. Analysis of alpha diversity (species per formation) shows that diversity
rose initially to Cambrian Stage 5, declined into Guzhangian and Paibian before returning to Stage 5 levels by the end of
the Cambrian. This pattern is replicated in Laurentia and West Gondwana. We show that taxonomically diagnostic ossicles found
in isolation typically occur significantly earlier than the first articulated specimens of the same taxa and provide important
information on the first occurrence and palaeobiogeographical distribution of key taxa, and of the phylum as a whole.
</p
