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https://scmp.com/news/world/united-states-canada/article/3007733/nightmare-crab-cartoon-eyes-scientists-discover
World/ United States & Canada

Nightmare crab with cartoon eyes: scientists discover bizarre crustacean from the time of the dinosaurs

  • Called ‘Callichimaera perplexa’, or ‘perplexing beautiful chimera’, the cute but peculiar critter swam the seas 95 million years ago
  • Unusual creature with wrench-like claws and bulbous eyes could make scientists ‘rethink what a crab is’
An artistic reconstruction of Callichimaera perplexa. Image: Oksana Vernygora/University of Alberta

Scientists have discovered a new species of crab that swam the sea 95 million years ago.

The small, pocket-sized crab, named Callichimaera perplexa, was very different from its modern-day cousins. This crab sported a tiny lobster-esque shell, legs flattened like oars and huge peepers that protruded from its head, which, researchers said, show that the creature used its eyes actively for whatever it did for a living.

An artistic reconstruction of Callichimaera perplexa. Image: Elissa Martin/Yale Peabody Museum of Natural History
An artistic reconstruction of Callichimaera perplexa. Image: Elissa Martin/Yale Peabody Museum of Natural History

But it is not only the critter’s cartoon appearance that has some researchers tickled, it is also what the ancient animal means to science. Javier Luque, a postdoctoral palaeontologist at both Yale University and the University of Alberta, said the “cute” and “unusual” decapod crustacean is going to make scientists “rethink what a crab is”.

“It gives us information about how novel body forms can evolve over time,” Luque said in an interview on Thursday.

Luque said he made the discovery in 2005 in the mountains in Pesca, Boyaca, in Colombia. Luque, who was an undergraduate geology student at the time, said he was hunting for fossils when he uncovered a trove of specimens from crustaceans – shrimp, lobsters and crabs with big, bulbous eyes.

Luque and his research team, who have been studying the well-preserved fossils found in Colombia and the US, published their findings on Wednesday in the journal Science Advances. The research provides insight into a creature so peculiar that it has been dubbed “the platypus of the crab world”, according to a news release.

So what do we know about this wide-eyed critter?

The crab lived during the mid-Cretaceous period – when dinosaurs ruled the Earth, landmasses were in motion and the oceans were taking shape. And based on where the fossils were found, it lived in what is now Colombia, Northern Africa and the United States, more specifically, Wyoming.

Its name, Callichimaera perplexa, means “perplexing beautiful chimera,” an allusion to a Greek mythological creature that had body parts from different animals. Makes sense. Luque said researchers believe the crab had a “mosaic of body parts”, including unprotected compound eyes, a spindle-shaped body and leg-like mouthparts that suggest it retained larval traits into adulthood.

The crab’s body was about the size of a quarter coin.

Its eyes were so large that, had it been a human, it would have had eyeballs as big as soccer balls.

Its legs were built more for swimming, not crawling. Its wrench-like claws made it a powerful little hunter.

And had the crab lived another 95 million years or so, it likely would have made it to Hollywood.

Luque, the lead author of the study, told Live Science that “I call it my beautiful nightmare because it was so beautiful and frustrating” for the researchers to comprehend.

It gives us information about how novel body forms can evolve over time Javier Luque, palaeontologist

Heather Bracken-Grissom, an evolutionary biologist at Florida Internal University who specialises in decapods, said that there are more than 7,000 species of crabs living today.

This “bizarre find”, she explained, will allow scientists to re-evaluate what they know about them.

“This new transitional fossil is making us rethink how crabs have evolved over time because it’s introducing this unique body form we weren’t aware of before,” Bracken-Grissom said. She said that it reveals “an early lineage in the crab tree of life”.