| Gecarcinucidae | |
|---|---|
 | |
| Thelphusa indica | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Brachyura |
| Section: | Eubrachyura |
| Subsection: | Heterotremata |
| Superfamily: | Gecarcinucoidea |
| Family: | Gecarcinucidae Rathbun, 1904 [1] |
| Genera | |
TheGecarcinucidae are afamily of truefreshwater crabs. They are found throughoutSouth Asia,Southeast Asia andNew Guinea, with a single genus found inAustralia.[2]
The familyParathelphusidae is now demoted to the rank of subfamily, as theParathelphusinae, within the Gecarcinucidae.[3] "Family" Parathelphusidae is now considered as a junior synonym.[4]
The Gecarcinucidae are thought to have originated in theIndian subcontinent when it was anisland continent in thePaleogene, despite not being of ancientGondwanan origins themselves (unlike other lineages that are thought to have originated in Insular India). Divergence estimates indicate that the Gecarcinucidae originate fromSoutheast Asian ancestors that dispersed to India during the middle Eocene, before India collided with Asia. This is thought to have occurred due to India drifting close enough to Southeast Asia to allow for biotic exchange between both regions. As the Gecarcinucidae are a freshwater group that could not disperse via marine habitats, this indicates that temporaryland bridges may have formed in the Eocene between India and Southeast Asia, allowing for the dispersal of freshwater organisms to India while it was still isolated. Following theIndia-Asia collision, the Gecarcinucidae dispersed back into mainland Asia, and from there to Australasia.[5]
The Gecarcinucidae are thought to be thesister group to thePotamoidea (the superfamily comprising thePotamidae andPotamonautidae).[5]