Loxoconcha muelleri ( Méhes, 1908 )

RAUSCH, LEA, STOICA, MARIUS & LAZAREV, SERGEI, 2020, A Late Miocene - Early Pliocene Paratethyan Type Ostracod Fauna From The Denizli Basin (Sw Anatolia) And Its Palaeogeographic Implications, Acta Palaeontologica Romaniae 16 (2), pp. 3-56 : 41

Loxoconcha muelleri ( Méhes, 1908)

Fig. 27 a-g

1908 Cythereis mülleri n. sp. - Méhes, p. 563, pl. 9, fig. 1-4, fig. 8, fig. 15-18.

1985 Loxoconcha muelleri (Méhes) - Jiříček, p. 403, pl. 55, fig. 10-13.

2016 Loxoconcha muelleri (Méhes) - Stoica et al., p. 865, pl. 6, fig. 1-9.

Description. The carapace has an oval rhomboidal shape in lateral view. The female carapace is slightly oblique to oval rhomboidal in shape, high, compressed and the ventral and dorsal margin run almost parallel to each other. The male carapace is slightly more elongated and has an extended dorsal margin. The straight running dorsal margin passes smoothly onto the broadly rounded anterior end that continues smoothly onto the slightly convex and arcuate ventral margin. The ventral margin is recurving towards the posterior end that, in the posteroventral area of females, shows a slight inflation. Unlike L. ex. gr. eichwaldi the surface of this species is less and irregularly pitted. The inner lamella is well developed along the posterior-and anterior margin and the amphidont hinge is represented by a crenulated bar bearing teeth at each end of the LV, whereas at the RV two distinct tooth sockets are observed. Dimension: L = 0,64 – 0,66 mm, H = 0,39 – 0,44 mm, the minimum sizes include juveniles too.

Chronostratigraphical and geographical distribution. L. muelleri has been described in the fossil record from the lower Pannonian (Zone A-E/E 3) of Hungary, the Vienna Basin of Austria and Slovakia ( Méhes, 1908; Jiříček, 1985) as well as in the Black Sea basin, the Maeotian of the Dacian Basin ( Stoica et al., 2016; Lazarev et al., 2020 (submitted)). It has further been described outside the Paratethys domain from the latest Miocene of the Mediterranean of Greece, Crete, France and Spain ( Faranda et al., 2007; Gliozzi et al., 2007; Stoica et al., 2016).

Ecology. L. muelleri inhabits shallow brackish water environments and can be found with L. eichwaldi Livental and C. agrigentina Decima (“ Cyprideis - Loxoconcha assemblage”) in low mesohaline habitats ( Grossi et al., 2015).

Figures

Fig. 27a-g Loxoconcha muelleri; a LV, external view, ♀; b, c RV, external view, ♀; d Carapace, dorsal view, ♀; e Carapace, ventral view, ♀; f LV, internal view, ♀; g RV, internal view, ♀; h, i Loxoconcha aff. muelleri; h LV, external view, ♀; i RV, external view, ♀; (all specimens from section A; a-g from sample 2 m, 19 m and 23 m; specimens h-I from sample 14 m).