The first of 25 equally most parsimonious trees obtained from a heuristic search with 100 random taxon additions of the LSU sequence alignment using PAUP v. 4.0b10. The scale bar shows 10 changes, and bootstrap support values from 1 000 replicates are shown at the nodes. Thickened lines indicate the strict consensus branches and novel sequences are printed in bold face. The different families are indicated with coloured blocks. The tree was rooted to Saccharomyces cerevisiae (GenBank no. Z73326).