An international team of paleontologists have found an exceptionally preserved fossilized remains of an enigmatic new type of crab, Callichimaera perplexa, which lived approximately 95 million years ago (mid-Cretaceous period) in what are now Colombia and the United States.
Callichimaera perplexa (perplexing beautiful chimera) was about the size of a quarter and had large and unprotected compound eyes, bent claws, leg-like mouth parts, exposed tail, and small body.
It is the earliest example of a swimming arthropod with paddle-like legs since the extinction of sea scorpions more than 250 million years ago.
The ancient creature is so unique and strange that it can be considered the ‘platypus of the crab world.’ It hints at how novel forms evolve and become so disparate through time.
Normally, we think of crabs as big animals with broad carapaces, strong claws, small eyes in long eyestalks, and a small tail tucked under the body. Callichimaera perplexa defies these crabby features and forces a re-think of the definition of what makes a crab a crab.
The discovery is reported in the journal Science Advances.