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Iron pyrite, often mistaken for gold, can conceal small amounts of genuine gold. More intriguingly, researchers uncovered a new, exquisitely preserved prehistoric arthropod within pyrite samples recovered from Beecher’s Trilobite Bed near Rome, New York—a renowned fossil locality.
Published in Current Biology, the study reveals the arthropod’s anatomy. Researchers employed computed tomography to generate thousands of X‑ray slices, capturing the specimen’s full 3‑D structure. The preservation likely resulted from a submarine landslide that trapped the organism in iron pyrite. The creature inhabited the ocean floor roughly 450 million years ago during the Ordovician. It has been christened Lomankus edgecombei, honoring Greg Edgecombe of the Natural History Museum, London.
Luke Parry, associate professor in Oxford’s Department of Earth Sciences and lead author, explained to CNN that pyrite preservation of this quality is exceptionally uncommon—only a few sites have yielded such specimens in the past 500 million years. Soft tissue decay normally precludes such fossilization.
Xiaodong Wang
Lomankus edgecombei is an invertebrate within the arthropod phylum, which encompasses organisms such as centipedes, crustaceans, millipedes, and spiders. It belongs to the extinct megacheiran clade, which flourished between 485 and 538 million years ago during the Cambrian and possessed prominent frontal appendages for prey capture. Studying this species offers a window into the evolutionary history of those distinctive head appendages.
The CT data enabled a detailed 3‑D reconstruction, revealing a creature that resembles modern shrimp rather than the dramatic arthropods often imagined from the past. Lacking eyes, its frontal appendages were modest, suggesting a tactile, rather than predatory, function. Its mouthparts and antennae bear resemblance to those of contemporary spiders or scorpions.
Parry noted that Lomankus demonstrates that megacheirans did not terminate in the Cambrian but continued diversifying, with their once‑prominent appendages repurposed for new functions. Co‑author Yu Liu of Yunnan University observed that the creature’s head closely mirrors early Cambrian megacheirans from China, except for its eye‑less condition—indicating a likely deeper, darker habitat.
