They first appeared in the Tithonian age of the Late Jurassic epoch, 145–152 million years ago.

Porcelain crabs have large chelae (claws), which are used for territorial struggles, but not for catching food.

[7] They are common under rocks, and can often be found and observed on rocky beaches and shorelines, startled creatures scurrying away when a stone is lifted.

They feed by combing plankton and other organic particles from the water using long setae (feathery hair- or bristle-like structures) on the mouthparts.

[4] Some of the common species of porcelain crabs in the Caribbean Sea are Petrolisthes quadratus, found in large numbers under rocks in the intertidal, and the red-and-white polka-dotted Porcellana sayana, which lives commensally within the shells inhabited by large hermit crabs.