Fig 1.
Four competing hypotheses of the phylogenetic relationship of extant echinoderms.
Most phylogenetic studies place Echinoidea and Holothuroidea as sister groups. The difficulty lies in the placement of Ophiuroidea; different methods favor different positions for brittle stars. A) The predominant hypotheses of how extant echinoderms are related are the Asterozoan and Cryptosyringid hypotheses. B) Two other alternate hypotheses based on mitochondrial gene alignments.
Fig 2.
Phylogenetic relationship of extant echinoderms.
Support values for the phylogenetic trees using RAxML and PhyloBayes on the dense and sparse supermatricies. Each node is scored with three support values; an asterisk denotes 100/100/100 support. The first support value is the dense supermatrix RAxML 1,000 bootstraps, the second value is the sparse supermatrix RAxML 100 bootstraps, and the third value is the dense supermatrix PhyloBayes posterior probabilities. The phylogram presented here is from the dense supermatrix RAxML analysis. See S2 Fig. for the tree topology predicted by the PhyloBayes analysis.