A new genus and species of mantis shrimp from Australia and Japan (Stomatopoda: Tetrasquillidae), with a revised diagnosis of Tetrasquillidae and a key to its genera

Abstract A new genus and species of lysiosquilloid mantis shrimp is described from Australia and Japan. It is unique in Stomatopoda by its unusual telson ornamentation in which the short intermediate and lateral primary teeth, accompanied by a row of short, graded serrations inward of the intermediate teeth, partially overhang a row of minute submarginal denticles. Although distinctive as a new genus and species, Incertasquilla chimeragen. et sp. nov. does not fit clearly into existing lysiosquilloid families as currently diagnosed and, in some respects, shares a mosaic of features present in several families. Incertasquilla chimeragen. et sp. nov., however, currently fits best into Tetrasquillidae, where it is tentatively placed, although further phylogenetic study may show it belongs in a separate family altogether. In the light of the new character combinations presented by the discovery of Incertasquilla chimeragen. et sp. nov., a revised diagnosis for Tetrasquillidae and updated key to the genera are provided. The discovery of Incertasquilla chimeragen. et sp. nov. expands the described lysiosquilloid fauna to 14 genera and 30 species in Australia, and 10 and 16 in Japan, respectively.