A newly discovered crab-like creature is so strange, the scientists who discovered it have literally named it "perplexing".
"Callichimaera perplexa is so unique and strange that it can be considered the platypus of the crab world," said Javier Luque, who first found a fossil of the "beautiful nightmare" in 2005 and led the study into just what on Earth it was.
Its name also references the chimera, a hybrid creature from Chinese mythology made up of a lion, goat and snake.
Callichimaera, which lived in the Americas and western Africa about 90 million years ago, had a shrimp-like mouth, lobster-type shell and socket-less eyes so big they'd be the equivalent of soccer balls on a human face.
"It looked like a crab, but I thought it was more like a spider," Luque told Live Science, calling it the "strangest crab that has ever lived".
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After collecting more than 70 specimens from across the Atlantic, Luque said he realised he'd uncovered an entirely new branch of the crab family tree.
"Usually we think of crabs as big animals with broad carapaces [shells], strong claws, small eyes in long eyestalks, and a small tail tucked under the body. Well, Callichimaera defies all of these 'crabby' features and forces a re-think of our definition of what makes a crab a crab."
Callichimaera perplexa - which literally translates as 'perplexing beautiful chimera' - was unveiled in journal Science Advances this week, alongside a number of other ancient sea creatures new to science, mostly shrimp.