A phylogenomic framework and timescale for tunicates

Tunicates are the closest relatives of vertebrates and are widely used asmodels to study the evolutionary developmental biology of chordates. Their phylogeny,however, remains poorly understood and to date, only the 18S rRNA nuclear gene andmitogenomes have been used to delineate the major groups of tunicates. To furtherresolve their evolutionary relationships and provide a first estimate of their divergencetimes, we used a transcriptomic approach to build a supermatrix consisting of 258evolutionarily conserved orthologous genes for representative species of all majortunicate lineages.