A list of biologists long enough to choke a horse has completed a new tree of life for animals, resolving the evolutionary relationships among all the major groups and suggesting some weird things about the origins of animals with well-developed tissues.

This was the surprise tissue finding — comb jellyfish (jellies with well-developed tissues) diverged from other animals even before the lowly sponge, which has no tissue to speak of.

Either comb jellies evolved their complexity independently from other animals or sponges became greatly simplified through the course of evolution, said study co-author Casey Dunn of Brown University.

If corroborated, “this would significantly change the way we think about the earliest multicellular animals,”  Dunn said. The results are detailed in the March 6 issue of the journal Nature.

These gigantic trees of life (this one is said to be the most comprehensive animal tree of life to date) require massive computer power to run algorithms and resolve huge matrices of data into the simplest and best explanation for evolutionary relationships. The animal tree demanded the power of more than 120 processors housed in computer clusters in labs around the globe.

The new tree also shows that millipedes and centipedes are more closely related to spiders than to insects. The pedes-spiders relationship shows it counts when you have a leg up on things.