Scientists recently unearthed hundreds of pristinely preserved fossils from rock formations in Colombia and United States, including a 95-million-year-old crab that is completely redefining what makes a crab what it is.
All the fossils date back 90 to 95 million years ago during the mid-Cretaceous period.
In a study published on the journal Science Advances, an international team of researchers reveal the details about the amazing cache of sea creatures they uncovered, which included an incredibly bizarre ancient crab dubbed the Callichimaera perplexa.
This particular animal is so strange that the researchers are even calling it as "the platypus of the crab world," according to a press release from Yale University.
Meet The Callichimaera Perplexa
Named after the mythological chimera, the Callichimaera perplexa's whole name translates to "perplexing beautiful chimera." Chimeras are known for having features from a number of different animals.
The newly discovered crab had strange mix of features as well: a mouth like a shrimp's, shell like a lobster's, claws like a frog crab's, and paddle-like legs similar to the extinct sea scorpion's. The Callichimaera perplexa is actually the earliest known swimming arthropod with this type of legs since sea scorpions died out 250 million ago.
This quarter-sized creature feature characteristics that's normal of crab larvae originating from the open sea, suggesting that certain ancient crabs may have kept some of their larval traits even as they developed into adults. It's possible, the researchers point out, that they simply amplified these traits and developed a new body in an evolutionary process known as heterochrony.
"It hints at how novel forms evolve and become so disparate through time," said lead author and paleontologist Javier Luque from Yale University. "Usually 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. Well, Callichimaera defies all of these 'crabby' features and forces a re-think of our definition of what makes a crab a crab."
Discovering Fossils In New Destinations
Another significance of the new study is the tropical location of the cache of fossils. Luque points out that only a few researchers search the tropics for such discoveries since it's more challenging to look for fossils amid the dense tropical forests.
"It is very exciting that today we keep finding completely new branches in the tree of life from a distant past, especially from regions like the tropics," Luque explained, adding that these places are known to be extremely diverse. However, scientists know about the historical diversity of these hotspots the least.