Strange Chimera crab sheds new light on crustacean evolution

‘Unusual and cute’ creature from the dinosaur era looked nothing like a modern-day crab.

he strangest crab that every lived? Callichimaera perplexa was a bizarre mixture of different features ( Oksana Vernygora, University of Alberta/PA)

A mixed-up crab from the dinosaur era has perplexed scientists with its bizarre collection of species features.

The crustacean, which lived around 90 million years ago, was named after the Chimera – a monster from Greek myth with a lion’s head, goat’s body and snake’s tail.

In a similar way, the newly discovered bug-eyed crab had characteristics that seem all wrong.

‘Unusual and cute’: Callichimaera perplexa (Elissa Martin, Yale Peabody Museum of Natural History/PA)

Lead researcher Dr Javier Luque, from the University of Alberta in Canada, described the creature as “unusual and cute”.

He said: “We started looking at these fossils and we found they had what looked like the eyes of a larva, the mouth of a shrimp, claws of a frog crab, and the carapace of a lobster.

“We have an idea of what a typical crab looks like – and these new fossils break all those rules.”

Fossil of Callichimaera perplexa embedded in stone (Daniel Ocampo R, Vencejo Films/PA)

Around 70 of the fossil crabs were found in the Andes mountain range in Colombia, which was a shallow coastal sea during the Cretaceous period.

Exceptional preservation allowed scientists to pick out details including paddle legs and bulging eyes, suggesting a lifetime of swimming rather than crawling in the sand.

The team named the crab, whose body was about the size of a 5p piece, Callichimaera perplexa, meaning “perplexing beautiful chimera”.

Dr Luque added: “Callichimaera perplexa 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.”