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Thyasiridae |
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Prothyasira peroniana Iredale, 1930 Description: Shape shell with a single very strong posterior fold located between 2 strongly keeled ridges (see Fig. 2); height greater than width, umbo central, lunule large and shallow. Exterior smooth or with weak commarginal riblets ventrally, often with irregular growth ridges; no radial sculpture. Interior smooth, muscle scars not apparent, margin smooth. Hinge left valve without teeth, right valve with a single cardinal tooth, no marginal teeth. Ligament mainly internal, long, narrow. Shell colour white. Size: Up to 8 mm in height. Distribution: Known from Cape Moreton, Qld, southwards to central South Australia. Habitat: Subtidal, 66 – 384 m depth. Comparison: See Parathyasira resupina below for comparison with that species. Prothyasira peroniana is very similar to Prothyasira adelaideana Iredale, 1930, but the holotype of that species is much larger at 18.5 mm in height. Fig. 1: Off Jibbon, Port Hacking, NSW, in 85 m (C.unreg) Fig. 2: Posterior view. Off Port Hacking, NSW, in 55 fathoms (101 m) (C.120494) |
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