The late Middle Jurassic lagerstätte at La Voulte-sur-Rhône, in the Ardèche region of southwestern France, offers paleontologists an outstanding view of an undisturbed paleoecosystem that was preserved in fine detail as organisms died at the site and settled to the bottom of a shallow epicontinental sea, with a folded floor that in places exceeded 200 m at this site. The site preserves a marine system of the Lower Callovian stage, a little over 160 mya. The sequence is exposed in a series of quarries at La Boissine, west of the village of La Voulte-sur-Rhône. Iron pyrites in the silty shale are symptoms of an anoxic environment. The site was recognized among French paleontologists from the mid-nineteenth century for its finely detailed fossils.

The Thylacocephala are group of extinct probable mandibulate arthropods, that have been considered by some researchers as having possible crustacean affinities. As a class they have a short research history, having been erected in the early 1980s.