Extraordinary morphological changes in valve morphology during the ontogeny of several species of the Australian ostracod genus Bennelongia (Crustacea, Ostracoda) Author Deckker, Patrick De Author Martens, Koen 9272757B-A9E5-4C94-B28D-F5EFF32AADC7 urn: lsid: zoobank. org: author: 9272757 B-A 9 E 5 - 4 C 94 - B 28 D-F 5 EFF 32 AADC 7 & Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B- 1000 Brussels, Belgium. & University of Ghent, Department of Biology, K. L. Ledeganckstraat 35, B- 9000 Gent, Belgium. text European Journal of Taxonomy 2013 2013-01-31 36 1 37 journal article 22336 10.5852/ejt.2013.36 13fb5aaa-91be-4204-90f0-93a492637789 2118-9773 3806624 B54F52A3-823F-49ED-978C-FDF1AEE3D201 Bennelongia cf. barangaroo nov. sp. Figs 16-18 Bennelongia dedeckkeri Shearn, Koenders, Halse, Schön & Martens, 2012 Figs 19-21 We examined specimens of B. cf. barangaroo nov. sp. from McNeil Claypan in Western Australia and of B. dedeckkeri from Lake Dunn in Queensland . From the former locality, we only had A-1 and A-2, but from the latter we also had specimens of stages A-3 and A-4. Both species have a very similar appearance and are closely related. Their ontogeny is here discussed together. The broad morphological characteristics of these species are, in many ways, similar to those of B. gwelupensis Martens et al ., 2012 (see below) for the following reasons: pseudo-punctation is visible on the outer surface of the valves in A- 1 specimens ( Fig. 16 with 8 lateral views), more pronounced reticulation is obvious in A-2 and much more prominent in A- 3 specimens ( Fig. 17 with dorsal views), although there are areas in the dorsal and postero-dorsal regions which appear smooth, but this may be seen on specimens that were not fully calcified. The domes are somewhat visible in A- 2 specimens and more obvious in A- 3 specimens ( Fig. 16 ). The cones with outer lips and setae are clearly visible ( Fig. 19 , middle), but overall these conical features are much fewer than in B. gwelupensis . Nevertheless, the pores penetrate through the entire valves and are seen from the inside ( Fig. 18 , bottom left). Once again, the inner lamella and selvage are present in A- 1 specimens , but not as broad as in B. gwelupensis (see below). The pattern in the younger instars remains the same: the valves of younger instars are more reticulated on the outside, the domes appear to be faintly distinguishable in A-1 and A- 2 specimens ( Figs 18-19 ) and are much more prominent in A-3 and even more so in A- 4 specimens . The domes in these earlier stages appear to be overgrown and display some reticulation that resembles some pseudo-punctation, but may be the result of over-calcification. They also possess the ubiquitous single sieve pores with seta ( Fig. 21 ), also seen in all other species discussed here. The nature of the reticulation around the domes ( Fig. 20 ) is somewhat puzzling in its arrangement, as it is reminiscent of an irregular meshwork. A better understanding of the process of calcification may help understand how this feature is formed. Once again, the domes differ in size ( Fig. 21 ), and in these species, the posterior one is the largest of the two. The pseudo-punctation is obvious in A-1 and A- 2 specimens but would have replaced the reticulated nature of the outer valves as seen in A-3 and A-4 ( Fig. 20 ). The cones are present especially near the anterior and posterior margins of the valves, but are definitely not abundant. In the vicinity of the domes, the cones are quite small, but retain their outer lip ( Fig. 21 ).