Brevisomabathynella gen. nov. is established for two new species, B. cooperi sp. nov.
and B. cunyuensis sp. nov., from Western Australia. An illustrated description of both
species is given. The two species stand out in the family Parabathynellidae by their
pygmoid body (the ratio of length to width: 5) and the relatively long head (equaling
the anterior five thoracic segments combined). The following characters of both new
species associated with the mouthparts are also unique within the Parabathynellidae:
(i) the gargantuan labrum with a high number (〉 30) of narrow teeth, (ii) the
incisor process with four main and three tiny additional teeth, arranged in two size
groups, and (iii) the two disto-inner spines of the distal endite of the maxillule
being longer than the terminal spines. These unusual characters seem to have developed
in response to the predatory habits, which is evidenced by the presence of an
unidentified ostracod prey in the gut of B. cunyuensis. The new genus, with its
primitive characters, closely resembles the genus Notobathynella Schminke, 1973.