A phylogenetic review of the genus Atopobathynella Schminke, 1973 (Crustacea, Malacostraca, Bathynellacea) with three new species from southeastern India

To date, the genus Atopobathynella Schminke, 1973, contains 12 Gondwanan species, including two species from India. Three new species of this genus, viz. A. indica sp. nov., A. nelloreensis sp. nov., and A. inopinata sp. nov., from southeastern India are described herein. The various characters and their states in Atopobathynella, in relation to other parabathynellid species known so far, are discussed; especially its closeness with the genus Kimberleybathynella is highlighted. A morphological phylogenetic analysis of the genus Atopobathynella, along with its closely related genus Kimberleybathynella is also done, and the inter-relationships among the 15 species of Atopobathynella and six species of Kimberleybathynella are deduced, using the software PAUP 4.0b10. This analysis, based on 39 unordered characters, has yielded 23 most parsimonious trees, with a length of 138 steps, a consistency index (CI) of 0.3768, a homoplasy index (HI) of 0.6232, a retention index (RI) of 0.6211, and a rescaled consistency index (RC) of 0.2341. The cladogram thus obtained suggests the grouping of ((A. wattsi, A. glenayleensis), (A. readi, ((((A. gascoyneensis, A. hospitalis), A. hinzeae), (((A. compagana, A. chelifera), A. valdiviana), (((A. operculata, A. paraoperculata), A. nelloreensis), (A. indica, A. inopinata)))), (A. schminkei, (((((K. gigantea, K. kimberleyensis), K. argylensis), K. pleochaeta), K. mandorana), K. hexapoda)))), outgroup). It also shows that the five Indian species are nestled between the Australian Atopobathynella and Kimberleybathynella species. The Indian species appear to be much derived as compared to their Australian counterparts. A brief note on the origin of Bathynellacea is also added at the end.