'Beautiful nightmare' crab species discovered by U of A paleontologist

The anatomy of an ancient crab recently discovered in the heart of the Andes Mountains is so bizarre, researchers have described it as a “beautiful nightmare.”  

'The perplexing nature of this particular anatomy, that's why it became a nightmare'

The strange anatomy of the chimera crab puzzled palaeontologists for years. (Elissa Martin)

The eyes of a larva, the mouth of a shrimp, the claws of a frog crab and the shell of a lobster: the anatomy of an ancient crab recently discovered in the heart of the Andes Mountains is so bizarre, researchers have described it as a "beautiful nightmare."  

With paddle legs and large bulbous eyes, it reminded scientists of a chimera, the mythological monster with a lion's head, a goat's body, and a snake's tail.

It took years for researcher Javier Luque to properly identify the crab which he named Callichimaera perplexa.

"That translates to baffling, perplexing, beautiful chimera," said Luque, a postdoctoral paleontologist in the department of biological sciences at the University of Alberta and Yale University

"It looks like something completely different from a crab."

The fossils discovered in a bed of clay in the Andes were perfectly preserved. (Daniel Ocampo)

After years of research, scientists have confirmed the tiny critter was in fact a crustacean, albeit a very strange one.

He admits, identifying the creature became an obsession.

"It's beautiful because the preservation is exquisite," Luque said. "But the perplexing nature of this particular anatomy, that's why it became a nightmare.

"We couldn't figure out where it fit because it was an entirely new branch."

The fossilized crabs, recovered from the Andes Mountains in 2005, date back to the Cretaceous period when area was covered with shallow sea waters.

The pocket-sized creatures would have spent most of their lives swimming and hunting for meals with their small but mighty claws.

I decided to swing my hammer one more time.-Javier Luque

Luque discovered the specimens during a month-long field excursion near Pesca, Colombia, after a long day of hiking through the mountain ranges in search of fossils.

"I decided to swing my hammer one more time before going toward home and then I hit a layer completely covered in fossils and invertebrates," Luque said in an interview with CBC Radio's Edmonton AM.

"And among all these wonderful crustaceans, it was this one that looked like a spider which was the most baffling.

"That's when we first became aware of this animal, but it was a long journey to figure out where it fit in the big picture."

More than 70 perfectly-preserved specimens were found in a bed of soft clay in outcropping of rocks.

The enigmatic crabs, no larger than a toonie, offer big insights into the evolution of modern crabs, Luque said.

While the features of some species became more pronounced over time, crabs adapted to their environment by becoming less "crab-like."

"They're more complex than we thought," he said. "They became more froggy.

"It shows that some species can go the other way."

Since his discovery, the same crabs have been found by paleontologists in Wyoming and northern Africa, Luque said.

The scientific fanfare of his discovery has Luque daydreaming of Hollywood, and more paleontological research in the mountains, of course.

"Hopefully people will enjoy this beautiful chimera which some people have called the next Pixar star, or maybe SpongeBob.

"Hopefully it will capture some imaginations because it's certainly a cute, beautiful nightmare."

Luque's conclusions on the crab were published this month in Science Advances.


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