Dromiacea

Dromiacea is a group of crabs, ranked as a section. It contains 240 extant and nearly 300 extinct species. Dromiacea is the most basal grouping of Brachyura crabs, diverging the earliest in the evolutionary history, around the Late Triassic or Early Jurassic. Below is a cladogram showing Dromiacea's placement within Brachyura:

Dromiacea Temporal range: Jurassic–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Dromia dormia (Dromioidea: Dromiidae) feeding on a sea urchin
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Malacostraca
Order:	Decapoda
Suborder:	Pleocyemata
Infraorder:	Brachyura
Section:	Dromiacea De Haan, 1833
Superfamilies
Dakoticancroidea † Dromioidea Glaessneropsoidea † Homolodromioidea Homoloidea

The larvae of Dromiacea resemble those of the Anomura more closely than those of other crabs.^{[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.

The fossil record of Dromiacea reaches back at least as far as the Jurassic, and, if Imocaris is indeed a member, into the Carboniferous.

Dromiacea primarily consists of two groups of superfamilies - Dromioidea and Homoloidea. See the below cladogram:

Recent studies have found that some of the families may not be monophyletic, but rather paraphyletic.

• The Dromioidea family Dromiidae may be paraphyletic with respect to Dynomenidae
• The Homoloidea family Homolidae is paraphyletic with respect to Latreilliidae