Rare Fossils of 400-Million-Year-Old Sea Creatures Uncovered

sea monster
An artist's interpretation of Aegirocassis benmoulai, a remarkably well-preserved 480-million-year-old arthropod known as an anomalocaridid.
(Image credit: Copyright Marianne Collins | ArtofFact)

Morocco's vast, rocky deserts were once covered with oceans teeming with life during the Ordovician period, about 485 million to 444 million years ago, a new study finds. But these stunning animals, now fossilized in mineralized splotches of violet, yellow and orange in the desert rock, would be unknown were it not for the tenacious work of a Moroccan fossil collector and a broke graduate student.

The Moroccan formation, known as the Fezouata Biota, holds some of the oldest known marine animals on Earth. It's home to more than 160 genuses, including an armored, wormlike creature (Plumulites bengtsoni) and a giant, filter-feeding arthropod (Aegirocassis benmoulae), according to the new study.

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Laura Geggel
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Laura is the managing editor at Live Science. She also runs the archaeology section and the Life's Little Mysteries series. 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.