I was reading the latest Circus of the Spineless and came across a post about ctenophores. A recent scientific paper has placed these animals, also known as comb jellies, at the base of the animal tree of life. This is surprising since until the present it was assumed sponges were the basal animal form. But this research makes sense to me- I vaguely recall that prior to early extinction events in Earth's history, during the Ediacaran Period, there were a lot of strange animals, some described as "immobile bags" and "mattress-like forms". Most of these animals were soft bodied. Could ctenophores be a window into this ancient world? Look at videos of comb jellies on youtube (two I liked: gooseberries and beroe), they remind me of spaceships, but any way you look at them they are very interesting animals.
Links to source material and images:
Diagram of evolutionary relationships: Check it out!
Circus of the Spineless #32
Cthe Ctenacious Ctenaphore: A story with a moral.
Interpreting the data: Long in-depth article
Dunn et al. 2008. "Broad phylogenomic sampling improves resolution of the animal tree of life". Nature 452, 745-749 (10 April 2008)