And no, Creatards..."Adam and Eve" Did Not Ride Them!

[Anomalocaris]

L

But recent discoveries indicates it was an arthropod, and probably more closely related to crabs and lobsters than other Arthropods...at most it can only take golf ball sized plugs of flesh from you when it catches you. 

I'm glad it'll be only a big chunk instead of my whole leg; nonetheless I'll be very careful before stepping into the surf at Key Largo. I thought this was the bits & pieces of carbonized critter in the Burgess Shale at Charles Walcott's quarry up in Banff Nat'l Park, but my, those eye stalks! Do they wiggle about to look in different directions? I'm also curious why the mouthparts have those little feathery brushes on them. To me that looks like some kind of filter-feeding or combing through debris, but from what you said they must be spines with that "one-way" feature that keeps prey from getting away from its grasp.

If I remember it also had a round, radicle-like mouth opening, and Stephen Jay Gould in Wonderful Life had said all these bits, found separately, were initially thought to be several different critters. After Ken Ham updates his museum in Kentucky, Adam and Eve will cruise down the River Pishon on its back, on their way out of the Garden of Eden.

Anamalocaris itself was found in Burgess Shale in banff NP, yes.     It was thought to be so unusual as to be an unique biological branch with few members and not closely related to anything more modern.

But since the 1980s many more different creatures that all clearly belonged to the same anamalocarid family have been discovered in various fossil beds around the world.   It's now clear that the anamalocarids were a large, diverse, and long lived family of creatures.    The first we know were from Cambrian, but they diversified and thrived at least until Devonian age 120 million years later.    This makes them quite an evolutionary success.  They were definitely not a short lived failed evolutionary experiment and oddity that Steven Gauld might have suggested 30 years ago.   We now also know anamalocarids had two flaps per body segment, one above and one below,  and these two flaps were homologous with the biramous appendages of trilobites, as well as the biramous appendages of the inferred common ancestors of other arthropod families.   This suggests their relationship with arthropod family is much closer than was recognized even quite recently, close enough for them to be arthropods.

The drawing show one kind of anamalocarid.   We know some anamalocarids had short, strong feeding appendages with short, sharp spike like growths upon them.   These are interpreted to be grasping and perhaps tearing appendages for feed upon larger prey, perhaps shelled animals like trilobites.   Others had long appendages with feathery growths. These are interpreted to be filter feeding mechanism, perhaps analogous to baleens on whales.