Conchyliocarida, from the Jurassic of France, have a conch-like carapace enclosing the whole body. The number of their somites, identified by the visible appendages, excludes them from Malacostraca. Caridean-like characters, including the large lamellar gills, bring them nearer to Malacostraca, end exclude them from other Classes. Their large functional compound eyes and the morphology of their limbs suggest a benthic life and predatory behaviour.
Conchyliocarida are represented by several forms at La Voulte sur Rhône, which are compared and contrasted to related forms elsewhere.