Saturday, June 18, 2011


This is what Sarotrocercus was first thought to look like, crawling around on the bottom. But no one found any trace of a leg, so there was a reconstruction of it swimming on its back in mid-water and using its gills to swim and breathe.

Sarotrocercus was a pelagic animal, meaning that it is in mid-water, and in the Burgess Shale, mid-water animals survived the mudslide, which mainly buried nektobenthic and benthic animals.

This image shows a close-up of Sarotrocercus, because Sarotrocercus only grew up to two centimeters. But that's definitely not the smallest animal in the Burgess Shale because Haikouichthys was probably one of the smallest, because it was only one centimeter. That's the size of your thumbnail. Sartotrocercus had two big compound eyes on stalks, two feeding appendages right next to the eyes, many gills on the bottom (which was usually the top), and weirdest of all, Sarotrocercus had a long tail with a club of spines at the end, which was probably used for defense.

I have a video of myself doing today's post. 


  1. How much "defense" could they have gotten from a spined club at the end of a tail a fraction of 2 cm long?

  2. Opabinia's long thing that sticks out of its mouth with the claw at the end, the tube part, is a little bit soft, so Sarotrocercus could probably fight off an Opabinia with the spiny club at the end of its tail.

  3. What would have been the eating habits of an opabinia? Would they have even eaten sarotrocercus?

  4. Where'd the Hallucigenia shirt come from? Do they have 'em in XXL with Wiwaxia on 'em?

  5. ... also, I know I could look it up myslef on this here Internet thing, but what are benthic animals, muich less nektobenthic ones?

  6. Benthic animals swim free in the water. Nektobenthic animals swim just above the bottom of the ocean.

    I didn't know that last one either but I read it on an earlier post :)

    You should get someone to make a glossary for this blog, a lot of those words are hard !

    I also love your T-shirt. Any M baby-dolls with Anomalocaris ?

  7. @FlavorDav I got the shirt here. The don't have Wiwaxia.

    Benthic is a creature that crawls around on the bottom of a body of water, and nektobenthic is a creature that lives on the bottom but swims a few inches above the bottom.

  8. @William Opabinia basically ate just whatever it could find that would fit in its mouth, but Sarotrocercus may not have been soft enough for Opabinia to eat, because Opabinia mainly went for small, soft creatures, such as lobopods.

  9. Oh dear, I confused "benthic" with "pelagic". "Benthic" means they're on the bottom. I really should leave this to the experts...

  10. @ABC Thanks. Not as up on my burgress fauna as I once was.

  11. Hi there, ABC,

    I love them, those weird critters.

    Also, thanks to your Mom for posting the video and to whoever did the camera work -- your Dad?

    And your cat (who looks very happy) soooo reminds me of my all-time favourite tabby, called Ikema, who used to sleep at my feet UNDER the duvet. That was nice and soft and warm to my feet :) .

    I'll be back!

    René, Amsterdam, Holland (a.k.a. the Netherlands)

  12. Hi ABC,

    just to keep you up to date, here is our new interpretation of Sarotrocercus

    Jo (currently New Haven)

  13. thats super wierd what are yall talking about