The Echinobase originated with work from the Davidson Lab and now expands on the concept of the GRN and provides updated systems diagrams showing an hour-by-hour account of the specification of sea urchin cell types during the early cleavage stages. See also Kudtarkar and Cameron 2017.
Echinobase link: http://www.echinobase.org/Echinobase/
Direct link to GRN: http://www.echinobase.org/endomes/
Kudtarkar P, Cameron RA. Echinobase: an expanding resource for echinoderm genomic information. Database (Oxford). 2017 Jan 1;2017.