The ancient creature Waptia fieldensis had a shrimp-like tail.
[Read more about the shrimp-like Cambrian critter]
An illustration showing W. fieldensis's rounded, paddle-like appendages and its spiny upper legs. It also had a mustache-shaped pair of antennae.
An upper shell known as a carapace (yellow) covered the head of W. fieldensis.
Some of the W. fieldensis fossils contained brain tissue.
The family tree of W. fieldensis. Notice how it falls within the mandibulata group because it has mandibles.
The thumb-size W. fieldensis was a powerful swimmer.[Read more about the shrimp-like Cambrian critter]
The shrimp-like tail of W. fieldensis. The fringed appendages under its body helped it paddle underwater.
W. fieldensis had stalked eyes.
W. fieldensis used its spiny front legs to grab and disembowel prey.
Charles Doolittle Walcott
The American paleontologist Charles Doolittle Walcott (1850-1927) discovered W. fieldensis in 1909 in the fossil-rich Burgess Shale deposit of the Rocky Mountains of British Columbia, Canada.
However, scientists haven't formally described the ancient critter in the scientific literature until now.
Drawings and notes
Walcott drew illustrations and described W. fieldensis in his notebook in 1909.
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Laura is the archaeology and Life's Little Mysteries editor at Live Science. She also reports on general science, including paleontology. Her work has appeared in The New York Times, Scholastic, Popular Science and Spectrum, a site on autism research. She has won multiple awards from the Society of Professional Journalists and the Washington Newspaper Publishers Association for her reporting at a weekly newspaper near Seattle. Laura holds a bachelor's degree in English literature and psychology from Washington University in St. Louis and a master's degree in science writing from NYU.