500millionyearold

A 500-million-year-old clawed beast rewrites the origins of spiders and crabs.

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The Cambrian chelicerate Megachelicerax cousteaui

image: Holotype specimen (part and companion) showing Megachelicerax cousteaui’s remarkable pincer-like chelicerae. vision Again Credit: Credit: Rudy Lerosey-Aubril It had been a long day teaching Rudy Lerosey-Aubril. As a reward, he returned to clean the Cambrian arthropod fossils he had just discovered for analysis. At first, the model showed all the expected characteristics of its … Read more

A 500-million-year-old spider has claws where they shouldn’t

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prehistoric spider genealogy illustration. it is under the sea and hunts with two front claws

The fossils were completely unremarkable. That’s what Harvard University paleontologist Rudy Lerosey-Aubril thought at first when he was examining arthropod fossils from the Cambrian period (538.8 to 485.4 million years ago). Lerosey-Aubril says: Normal Science. Early arthropod specimens do not have claws like this. Instead, Cambrian arthropods often have antennae in that region. In other … Read more