Bennelongia harpago 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 : 25-26

Bennelongia harpago De Deckker, 1981

Fig. 11

Diagnosis (modified after De Deckker 1981)

Cp in dorsal view with blunt anterior rostrum and rounded posterior, oval to sub-rectangular in lateral view, LV overlapping RV on all sides but more so antero-dorsally with hump-like thickening. External valve surface pseudopunctate with sparse, short setae. LV with dorsal margin highest at one third from the anterior where hump-like thickening occurs. RV with anteroventral flange absent and greatest height slightly anterior of the middle.

Measurements (in µm)

♀: RV: L = 1193, H = 736. LV: L = 1261, H = 792. Cp: L = 1256-1282 (n =3), W = 813, H = 765-788 (n =2).

Locality investigated

Lake Powlathanga, west of Charters Towers QLD, coordinates: 20º14’42.2” S - 145º58’8.2” E. Material was collected on 5 Jun. 2011 by RS and AK (Sample QLDP1A).

Material investigated

Two ♀♀ (W40013-W40014) from Lake Powlathanga, with soft parts dissected in a sealed slide and valves stored dry in a micropalaeontological slide. One carapace stored in a micropalaeontological slide (W40015).

Differential Diagnosis

Bennelongia harpago can be diagnosed from the other Bennelongia lineages by the anterodorsal hump-like thickening of the LV (absent in all other described lineages). Identification can be confirmed further by the small carapace (L = 1.2 mm, larger in B. cygnus , B. australis , B. pinpi , B. tunta and B. nimala lineages), the absence of an anteroventral lapel in the RV (present in B. cygnus , B. australis and B. nimala lineages) and the blunt anterior rostrum in dorsal view (more pronounced in B. australis , B. pinpi and B. tunta lineages).

Additional Description (modified after De Deckker & McKenzie 1981)

Cp ( Fig. 11 C-D) oval in dorsal view with rounded posterior and blunt anterior rostrum; oval to subrectangular in lateral view, LV overlapping RV on all sides (more so in the first one third from anterior, external valve surface pseudopunctate with sparse short setae.

LV ( Fig. 11A ) with pointed anteroventral beak-like expansion, dorsal margin highest at approximately one third from anterior where thickening of the valve forms a hump-like appearance.

RV ( Fig. 11C ) in lateral view with dorsal margin highest at slightly anterior to the middle. Anteroventral lapel very reduced to non-existent.

Remarks

Bennelongia harpago was described from a dam near Mt Teddy in Queensland, Australia ( De Deckker & McKenzie 1981). This study has provided molecular evidence from specimens in Lake Powlathanga that confirmed their species status. As there have since been nine additional species described from Western Australia and three described here, notes on the additional characters that now diagnose B. harpago from all described Bennelongia are provided below.

Ecology and distribution

Bennelongia harpago was originally recorded at a number of localities throughout Queensland ( De Deckker & McKenzie 1981). One of these populations (Lake Powlathanga) was sampled in this study showing that they still exist there. At present, males have not been recorded for this species.

Figures

Fig. 11. Bennelongia harpago De Deckker & Mckenzie, 1981, all from Lake Powlathanga, QLD. A. ♀, LVi (W40014). B. ♀, RVi (W40014). C. ♀, CpRl (W40015). D. ♀, Cp dorsal (RS35). E. ♀, RVi detail anteriorly (W40014). Scales: A-D = 500 μm, E = 100 μm.