Thylacocephala

Thylacocephala (from the Greek or ', meaning "pouch", and or ' meaning "head") is an extinct group of mandibulate arthropods, that are generally regarded as a kind of crustacean, though their exact position within this group is uncertain. As a class they have a short research history, having been erected in the early 1980s.

Ainiktozoon loganense ("Logan's enigmatic animal", from (aíniktós, "riddling, enigmatical"), living thing), is a fossil arthropod from the Silurian of Scotland.

Dollocaris is an extinct genus of thylacocephalan that lived during the Jurassic period. Fossils have been found in France, specifically the La Voulte-sur-Rhône lagerstätte. It is known for its massive compound eyes, giving Dollocaris a rather characteristic appearance. One species is currently known, D. ingens.