Bilaterian groups expected to present cytasters. Cytasters have been described in a wide sample of both deuterostome and protostome phyla (dark branches). Grey branches are used for phyla for which we found no available published information. More detailed studies are necessary to clarify the presence or absence of cytasters in these missing phyla, using modern techniques uniformly applied across different taxa. This phylogeny was adapted from Stach (2008)  for chordate relationships, Regier et al. (2010)  for arthropod relationships, and from Hejnol et al. (2009) , and Philippe et al. (2009)  for all other relationships.