Nav: Home

Scientists unearth 'utterly bizarre' chimera crab fossil

April 24, 2019

A chimera: a monster out of Greek mythology with a lion's head, a goat's body, and a snake's tail. That was what came to mind when University of Alberta paleontologists discovered a new--and bizarre--species of 90-95 million-year-old crab fossil with features of many different marine arthropods.

"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," said Javier Luque, lead author and postdoctoral paleontologist in the Department of Biological Sciences at the University of Alberta and at Yale University. "We have an idea of what a typical crab looks like--and these new fossils break all those rules."

But while the unusual crab may have features of many different families, the paleontologists found that it is actually an unusual new branch on the crustacean tree of life--not unlike a platypus of the crab world, explained Luque.

Discovery is in the details

The fossilized crabs, recovered from the Andes Mountains in Colombia, once lived in a shallow coastal sea during the Cretaceous period. Researchers recovered over 70 of the specimens in soft clay, together with hundreds of other crustaceans like shrimps and lobsters.

While the fossils are no bigger than a quarter coin, Luque explains that their exceptional degree of preservation allowed researchers to pick out fine details--such as paddle legs and large eyes, suggesting the crabs spent their lives swimming, rather than crawling as most crabs do.

"We found dozens of animals, from tiny baby specimens to mature individuals in which we found reproductive organs--a smoking gun that proves these were adult organisms and not larvae. We can even see individual facets on the large compound eyes of these creatures," said Luque. "It's an incredible amount of detail, and we've been able to reconstruct them like they were living yesterday."

That incredible degree of detail has even allowed researchers to create a detailed 3D model that's 3D-printer-ready.

"It's common to find novel body forms in older rocks, for instance from the Paleozoic when life was exploding into many new forms," said Luque. "This discovery, from the mid-Cretaceous, illustrates that there are still surprising discoveries of more recent, weird organisms waiting to be found, especially in the tropics. It makes you wonder 'what else is out there for us to discover?'"

The research was conducted with support from the Natural Sciences and Engineering Research Council of Canada (NSERC), the Killam Trusts, the Smithsonian Tropical Research Institute (STRI), the Colombian Geological Survey, the Colombian Association of Petroleum Geologists & Geophysicists, and the ARES Geological Corporation.

The paper, "Exceptional preservation of mid-Cretaceous marine arthropods and the evolution of novel forms via heterochrony" was published in Science Advances.
-end-


University of Alberta

Related Evolution Articles:

Chemical evolution -- One-pot wonder
Before life, there was RNA: Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich show how the four different letters of this genetic alphabet could be created from simple precursor molecules on early Earth -- under the same environmental conditions.
Catching evolution in the act
Researchers have produced some of the first evidence that shows that artificial selection and natural selection act on the same genes, a hypothesis predicted by Charles Darwin in 1859.
Guppies teach us why evolution happens
New study on guppies shows that animals evolve in response the the environment they create in the absence of predators, rather than in response to the risk of being eaten.
Undercover evolution
Our individuality is encrypted in our DNA, but it is deeper than expected.
Evolution designed by parasites
In 'Invisible Designers: Brain Evolution Through the Lens of Parasite Manipulation,' published in the September 2019 issue of The Quarterly Review of Biology, Marco Del Giudice explores an overlooked aspect of the relationship between parasites and their hosts by systematically discussing the ways in which parasitic behavior manipulation may encourage the evolution of mechanisms in the host's nervous and endocrine systems.
More Evolution News and Evolution Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...