PhysOrg once again brings prehistoric monsters to life:
Although the first fragments were described nearly one hundred years ago, they were assumed to be part of a crustacean-like animal. It was not then realised that other parts of the animal were also in collections, but had been described independently as jellyfish, sea cucumbers and other arthropods. …The last piece of the puzzle was found when the best-preserved specimen turned up in the old collections at the Smithsonian National Museum of Natural History, Washington DC. This specimen was first classified as an arthropod in the 1970s and 80s, and then as an unusual specimen of the famous monster predator Anomalocaris.
The new description of Hurdia shows that it is indeed related to Anomalocaris. Like Anomalocaris, Hurdia had a segmented body with a head bearing a pair of spinous claws and a circular jaw structure with many teeth. But it differs from Anomalocaris by the possession of a huge three-part carapace that projects out from the front of the animal’s head.
“This structure is unlike anything seen in other fossil or living arthropods,” says Ph.D. student Allison Daley, who has been studying the fossils for three years as part of her doctoral thesis.
It lived 500 million years ago, and was possibly the ancestor of arthropods – the armored animals that include everything from scorpions to cockroaches.