Re: What the heck is that?!? STEP ON THAT THING! Yikes!

[Tim Williams <tijawi@yahoo.com>]

B tH <soylentgreenistrex@yahoo.com> wrote:

> Opabinia!
> 
> This Cambrian life-form looks like something out of a
> sci-fi movie.  Good thing it was only finger-size.
> Brrrrr!
> 
> And I thought Anomalocaris was spooky.


Phylogenetic analyses recover _Opabinia_ as a "stem-group arthropod", among an 
assemblage of arthropods termed "Cambrian lobopodians" that also includes 
_Anomalocaris_ and relatives.  


Thus, these _Opabinia_ lie outside the great Euarthropoda clade that includes 
trilobites and modern arthropod groups (insects, crustaceans, arachnids, 
horseshoe crabs, myriapods, sea spiders), as well as outside both the 
Onychophora (velvet worms) and Tardigrada (water bears).  All these groups 
belong to the Panarthropoda.



Cheers

Tim