brittle star

In a paper published Wednesday in The Proceedings of the Royal Society B, a team of scientists describe the fossil of a brittle star that was petrified while regenerating three of its six limbs.

Small prey present in their environment at all temperatures included brittle stars, small crustaceans, worms, and molluscs.

In the case of brittle stars, that seems to be enough to learn by association, Notar, Johnsen and former Duke undergraduate Madeline Go report in the journal Behavioral Ecology and Sociobiology.

The corals were also crawling with critters, including squat lobsters, feathery brittle stars, and dense patches of anemones and sponges.

Millions of years ago, animals in this phylum—including starfish, brittle stars, sea cucumbers and sea urchins—were all bilateral.