Bennelongia barangaroo, De Deckker, 1981

Shearn, Rylan, Koenders, Annette, Halse, Stuart & Martens, Isa Schön and Koen, 2012, A review of Bennelongia De Deckker & McKenzie, 1981 (Crustacea, Ostracoda) species from eastern Australia with the description of three new species, European Journal of Taxonomy 25, pp. 1-35 : 9-10

Bennelongia barangaroo lineage

Remarks

Bennelongia barangaroo De Deckker, 1981 was originally described from Cauckingburra Swamp (near Lake Buchannan, QLD) and was diagnosed by valve and hemipenes structure (De Deckker 1981). The description included illustrations of specimens from other populations, additional to the type locality, one of which was from a creek bed near Cue in Western Australia (De Deckker 1981). The SEM plates show the type specimen with an obvious anteroventral lapel on the RV, and the specimen from Cue with a reduced or non-existent anteroventral lapel (De Deckker 1981). More recently, a revision of the Western Australian species of the genus Bennelongia established this lapel as an important morphological character at the species level ( Martens et al. 2012). Thus, it has become apparent that the population from Cue (De Deckker 1981) was likely to be a different species from the true B. barangaroo of Cauckingburra Swamp.

Although this finding regarding the specimens from Cue did not change the specific status of B. barangaroo , it did bring into question whether the other populations identified in the original description were actually B. barangaroo , or whether they were part of a more diverse species complex. Here further evidence is provided for this B. barangaroo species complex through the description of two new species within the lineage, both of which are clearly different from B. barangaroo and the specimen from Cue illustrated in De Deckker (1981).

The Bennelongia barangaroo lineage consists of three species, B. barangaroo De Deckker, 1981 , B. dedeckkeri sp. nov. and B. mckenziei sp. nov. They are characterized by a small carapace (L = 1000 µm, the smallest of all described Bennelongia species). They can be distinguished further from the B. cygnus and B. tunta lineages by the rounded dorsal margin of the Cp (triangular in B. cygnus , rectangular in B. tunta ), from the B. australis lineage by the less pronounced anterior rostrum in dorsal view, from the B. pinpi lineage by the less pronounced beak structure of the LV, from the B. nimala lineage by the small anteroventral overlap of LV over RV (large overlap in B. nimala ) and less elaborate external valve ornamentation and from the B. harpago lineage by the absence of an anterodorsal humplike thickening of the LV.