Scientists Find 500 Million Year Old Fossils of Lobster-like Creature

Posted on March 29, 2015

Scientists have discovered 508 million-year-old fossils of a lobster-like predator at the Marble Canyon site, which is part of the Canadian Burgess Shale fossil deposit. The fossil was discovered by palaeontologists at the University of Toronto (U of T) and the Royal Ontario Museum (ROM) in Toronto, as well as Pomona College in California. The ancient arthropod ancestor has been named Yawunik kootenayi.

Yawunik had two pairs of eyes and a 12-segmented trunk. It hunted with its long frontal appendages that each had three claws. Two of the claws had opposing rows of teeth that Yawunik used to catch prey.

Cedric Aria, lead author of the study from U of T, says in a statement, "This creature is expanding our perspective on the anatomy and predatory habits of the first arthropods, the group to which spiders and lobsters belong. It has the signature features of an arthropod with its external skeleton, segmented body and jointed appendages, but lacks certain advanced traits present in groups that survived until the present day. We say that it belongs to the 'stem' of arthropods."

The scientists think Yawunik could move its frontal appendages and claws backward and forward. It could spread them out for an attack and tuck them under its body for quicker swimming. The researchers say the creature is the most abundant of the large new species found at the Marble Canyon site and likely played a significant role in the ancient food chain.

A research paper on can be found here in the journal, Palaeontology.

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