Researchers find crabs' sideways walking evolved once 200 million years ago

8 articles · Updated · SciTechDaily · May 9

The eLife reviewed preprint, led by Yuuki Kawabata of Nagasaki University, analysed locomotion in 50 true crab species and evolutionary data spanning 344 species.
It found 35 species mainly moved sideways and 15 forward, tracing the trait to a shared Jurassic ancestor near the base of Eubrachyura.
Researchers say sideways movement may have helped true crabs diversify after the Triassic-Jurassic extinction, as changing seas and habitats created ecological opportunities.

If sideways walking is a superior survival tactic, why do some successful 'true crabs' still walk forward today?

Can the ancient secret of the crab's scuttle inspire the design of next-generation, all-terrain robots?