Molecular phylogeny based on increased number of species and genes revealed more robust family-level systematics of the order Euryalida (Echinodermata: Ophiuroidea)

Previous molecular analysis of the order Euryalida (Echinodermata: Ophiuroidea), has identified three monophyletic families, the Etuyalidae, Asteronychidae and Gorgonocephalidae. However, family-level relationships have remained unresolved due to inadequate taxon sampling and insufficient molecular markers. Here, we present a family-level revision of the Euryalida based on sequences from mitochondrial genes (16S rRNA and COI) and a nuclear gene (18S rRNA) from 83 euryalid ophiuroids. The monophyly of the three families, Euryalidae, Asteronychidae and Gorgonocephalidae is confirmed. The Euryalidae and Asteronychidae + Gorgonocephalidae are assigned to superfamilies, the Emyalidea and the Gorgonocephalidea, respectively. Three subclades within the family Gorgonocephalidae are identified and assigned to three subfamilies; Astrotominae includes Astrocrius, Astrohamma and Astrotoma, Astrothamninae (subfamily nov.) includes Astrothamnus and Astrothrombus with Gorgonocephalinae including the remaining genera. Morphological characters are consistent with the newly recognised superfamilies and subfamilies. (C) 2013 Elsevier Inc. All rights reserved.