[1] Dromiacea is the most basal grouping of Brachyura crabs, diverging the earliest in the evolutionary history, around the Late Triassic or Early Jurassic.
[citation needed] This may simply reflect their basal position in the crab phylogeny.
The superfamily Eocarcinoidea, containing Eocarcinus and Platykotta, was previously considered to be a member of the Dromiacea, but has since been transferred to the Anomura.
[4] The fossil record of Dromiacea reaches back at least as far as the Jurassic,[5] and, if Imocaris is indeed a member, into the Carboniferous.
[6] Dromiacea primarily consists of two groups of superfamilies - Dromioidea and Homoloidea.