Posted: Feb 26, 2020 10:50 pm
by Cito di Pense
From the article linked in the OP:

Over many, many years, they have basically devolved from a free-living jellyfish ancestor into the much more simple parasite we see today.

They've lost most of the original jellyfish genome, but retaining - oddly - a complex structure resembling jellyfish stinging cells. They don't use these to sting, but to cling to their hosts: an evolutionary adaptation from the free-living jellyfish's needs to the parasite's. You can see them in the image above - they're the things that look like eyes.

This informs me (at least) that this form evolved from preexisting aerobic multi-cellular forms. This is not (do correct me if I'm wrong) any evidence that multicellular anaerobic forms evolve independently of aerobic organisms. That's what the "umm, no" is about. I apologize profusely for not making sure to recognize explicitly your vaunted expertise in paleontology; you can take it as my recognition that you're more than capable of tooting your own horn.