Transcriptome assemblies associated with: A cnidarian phylogenomic tree fitted with hundreds of 18S leaves

Cnidarians have been an experimental system for a diversity of research
areas ranging from development to biomechanics to global change biology.
Yet we still lack a well-resolved, taxonomically balanced, cnidarian tree
of life to place this research in appropriate phylogenetic context. To
move towards this goal, we combined data from 26 new anthozoan
transcriptomes with 86 previously published cnidarian and outgroup
datasets to generate two 748-locus alignments containing 123,051 (trimmed)
and 449,935 (untrimmed) amino acids. We estimated maximum likelihood
phylogenies for both matrices under partitioned and unpartitioned
site-homogeneous and site-heterogenous models of substitution. We used the
resulting topology to constrain a phylogenetic analysis of 1,814 small
subunit ribosomal (18S) gene sequences from GenBank. Our results confirm
the position of Ceriantharia (tube-dwelling anemones), a historically
recalcitrant group, as sister to Hexacorallia across all phylogenies
regardless of data matrix or model choice. We also find unanimous support
for the sister relationship of Endocnidozoa and Medusozoa and propose the
name Operculozoa for the clade uniting these taxa. Our 18S hybrid
phylogeny provides insight into relationships of 15% of extant taxa.
Together these data are an invaluable resource for comparative cnidarian
research and provide perspective on the future of cnidarian systematics.