In the Cambrian Period, one of the mightiest predators cruising the primeval oceans was a critter about the size of a lobster, researchers say, and it wouldn’t win any beauty contests: “The animal is very strange looking” [New Scientist], says Allison Daley, coauthor of a new study. But even though it measured only about one and a half feet in length, it had enough natural weaponry to dominate the marine food chain about 505 million years ago. “This mouth is kind of nasty. I always use the analogy of a pencil sharpener,” said [study coauthor] Jean-Bernard Caron…. “You put anything into this and you get the prey completely cut and broken into pieces” [Toronto Star].
It took researchers several years of combing through fossils to piece together the bizarre jigsaw puzzle that is Hurdia victoria – an ancestor of arthropods such as insects, spiders and crustaceans…. The first fossilised scraps of Hurdia were discovered in 1912. These were followed by further body parts that were so varied and unusual that they were incorrectly classified as either jellyfish, sea cucumbers or shrimp-like crustaceans [The Independent]. The breakthrough came when paleontologists rediscovered a nearly complete fossil that had been found in the Canadian Rockies almost one hundred years ago, and realized the earlier fragments were all parts of the same species.
Hurdia sported stalked eyes like a shrimp, a circular jaw lined with fearsome teeth, and a bizarre, oversized head. Such shells or carapaces normally protect soft parts of the body, as seen in modern crabs and lobsters. “But this structure in Hurdia is empty and does not cover or protect the rest of the body,” says Daley. The researchers can only guess what it was used for. Caron suspects Hurdia, which appears to have been a good swimmer, would have used its pointed head to stir up sea sediments looking for things to eat [Vancouver Sun]. The researcher team describes the species in a new paper published in Science.
The Hurdia fossil also reveals details of the gills associated with the body, some of the best preserved in the fossil record. Most of the body is covered in the gills, which were probably necessary to provide oxygen to such a large, actively swimming animal [LiveScience].
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Image: Marianne Collins