Trapezioidea Miers, 1886

Ng, Peter K. L., Ahyong, Shane T. & Castro, Peter, 2023, Re-appraisal of the families and subfamilies of Trapezioidea Miers, 1886, with establishment of a new family, Ectaesthesiidae (Crustacea: Decapoda: Brachyura), Raffles Bulletin of Zoology 71, pp. 606-631 : 607-608

Superfamily Trapezioidea Miers, 1886

Remarks. We describe herein Ectaesthesiidae , a new family within Trapezioidea , and compare it with its presumed sister-taxon, Tetraliidae , using a suite of new morphological characters. In so doing, the character states for other families of Trapezioidea were re-assessed leading us to conclude that Calocarcininae Števčić, 2005 (sensu Ng et al., 2008) does not belong in Trapeziidae and should instead be recognised as a distinct family (see Remarks under account of Calocarcinidae ). Sphenomerides Rathbun, 1897 is not a calocarcinid as previously thought, but a trapeziid, belonging in its own subfamily, Sphenomeridinae Števčić, 2005 , within Trapeziidae Miers, 1886 (see Ng et al., 2008). Castro et al. (2004) had diagnosed members of Domeciidae as having fused (at least ankylosed and immobile) male pleonal somites 3–5, but our re-examination of the constituent genera showed that this is not the case. All pleonal somites in domeciids are actually freely articulating as in tetraliids.

As a result of morphological reassessment, we provide revised diagnoses for all the subfamilies and families of Trapezioidea , particularly for Calocarcinidae , new status, and Sphenomeridinae , new status.