Belongs within: Euarthropoda. The Euthycarcinoidea are a group of primarily aquatic arthropods known from freshwater or brackish water environments in the Late Ordovician or Early Silurian to the Middle Triassic (Vaccari et al. 2004). Their affinities have been the subject of much interest with some authors suggesting a relationship to modern hexapods. Characters (from Vaccari… Continue reading Euthycarcinoidea