Renngartenella sanctaecrucis Kristan-Tollmann in Kristan-Tollmann & Hamedani, 1973

Forel, Marie-Béatrice, Kolar-Jurkovšek, Tea & Jurkovšek, Bogdan, 2020, Ostracods from the ‘ Raibl Beds’ (Carnian, Late Triassic) of Belca section in Karavanke Mountains, northwestern Slovenia, Geodiversitas 42 (21), pp. 377-407 : 392

Renngartenella sanctaecrucis Kristan-Tollmann in Kristan-Tollmann & Hamedani, 1973

( Figs 7T, U ; 8 A-E)

Renngartenella sanctaecrucis Kristan-Tollmann in Kristan-Tollmann & Hamedani, 1973: 215 , 217-219, pl. 8, figs 1-6; pl. 11, figs 1, 3, 5, 6; pl. 12, fig. 10 — Liebermann 1979: 215, pl. 5, fig. 2 — Basha 1982: pl. 1, fig. 15 — Gerry et al. 1990: 96, pl. 1, figs 11-13 — Monostori 1994: 320, 322, figs 5/5-7 — Keim et al. 2001: fig. 8C.

EXAMINED MATERIAL. — More than 60 isolated valves.

OCCURRENCE. — Julian, early Carnian, Late Triassic, Heiligkreuz Formation, Italy (Kristan-Tollmann & Hamedani 1973); Carnian, LateTriassic, Italian Alps ( Liebermann 1979); Cordevolian, Carnian, Late Triassic, Jordan (Basha 1982); Carnian, Late Triassic, Devora-2A and Ramallah-1 boreholes, Israel (Gerry et al. 1990); Early Carnian, LateTriassic, Balatón Highland, Hungary ( Monostori 1994); Carnian, Late Triassic, Heiligkreuz Formation, Dolomites, Northern Italy (Keim et al. 2001); Nicoraella ? budaensis conodont zone, late Julian-?earliest Tuvalian, Carnian, Late Triassic, samples BE2, 18 ( Fig. 3 ), Belca section, ‘Raibl Beds’, Karavanke Mountains, Slovenia (this work).

DIMENSIONS. — Fig. 9.

DISCUSSION

Renngartenella sanctaecrucis has been found in samples BE2 and BE18 of the Belca section ( Fig. 3 ). While it is rare in sample BE18, it is very abundant in sample BE2. In the present state of our knowledge, R. sanctaecrucis is restricted to the Julian, early Carnian, Late Triassic. The length and height of all specimens available in the literature and in the present work are plotted in Fig. 9 . The size range of left valves is wider than that of right valves, the smallest and largest known specimens being left valves. There is no overlap of the size of the left valves between Belca and other localities, those found in Belca being significantly smaller. The same is not true for right valves as the size of the type material from Italy (Kristan-Tollmann & Hamedani 1973) overlaps the range of the Belca specimens. To reconstruct the ontogeny of R. sanctaecrucis , we used the ontogenetic information provided in the literature and complete carapaces provide correlation points. Fig. 9 first shows that the size difference between left and right valves of complete carapaces is not important: this limited dispersal is an additional tool to discuss the possible ontogenetic stages of R. sanctaecrucis . The anchor points ensured by complete carapaces allow the identification of the largest two stages, identified as A-1 and Adult ( Fig. 9 ). The upper limit of the large scatter plot preceding A-1 is very close for both valves so that these larger specimens might correspond to A-2. The youngest juveniles identified are left valves, as shown by their significant size difference with the smallest right valves. However, in the absence of additional characters such as inner structures, it is nearly impossible to further subdivide this large scatter plot. A common lower limit can be identified as shown by the dashed line in Fig. 9 but no inner boundary can be recognized.

Monostori (1994) formulated the hypothesis of sexual dimorphism for R. sanctaecrucis occurring in Hungary, elongate adults with narrowly arched posterior possibly being males. In Belca, only one right valve of adult has been identified so that the pattern discussed by Monostori (1994) cannot be recognized for adults at this locality. However, these two morphologies are visible in the present material, which also occur in the type material from the Heiligkreuz Formation in Italy (Kristan-Tollmann & Hamedani 1973). The first morphology has asymmetric anterior and posterior margins, with posterior end slightly subtriangular and maximum of curvature located lower than anterior one (Kristan-Tollmann & Hamedani 1973: pl. 8, figs 1-3, 5; Fig. 8C, E ). The second morphology is more rectangular in outline, with posterior end located higher and more rounded to subvertical at some specimens (Kristan-Tollmann & Hamedani 1973: pl. 8, figs 4, 6; Fig. 8A, B, D ). In the present state of our reconstruction, the two morphologies are visible very early in the development of this species. Following Monostori (1994), we interpret the first morphology as being males and the second one as being females.

Figures

FIG. 7. — Ostracods from the Belca section, Karavanke Mountains, northwestern Slovenia, Carnian, Late Triassic. All specimens are deposited in the micropalaeontology collections of the Geological Survey of Slovenia, under the numbers GeoZS6132 to GeoZS6239, preceded by sample number: A, Pontocypris? karavankensis Forel, n. sp., lateral view of a right valve, BE18 (GeoZS6174); B, C, Monoceratina sp.; B, lateral view of a right valve, BE21 (GeoZS6175); C, lateral view of a right valve, BE18 (GeoZS6176); D, Citrella? carniana Forel in Forel et al. 2019, lateral view of a right valve, BE2 (GeoZS6177); E, F, Judahella dizluense Kristan-Tollmann, 1980; E, lateral view of a right valve, BE18 (GeoZS6178); F, lateral view of a left valve, BE21 (GeoZS6179); G, Judahella cf. galli Kozur & Bolz in Bunza & Kozur, 1971, lateral view of a right valve, BE18 (GeoZS6180); H, Judahella sp., lateral view of a right valve, BE18 (GeoZS6181); I, Kerocythere cf. hartmanni Bolz & Kozur in Bunza & Kozur, 1971, lateral view of a right valve, BE18 (GeoZS6182); J, Kerocythere raibliana (Gümbel, 1869), lateral view of a left valve, BE18 (GeoZS6183); K-M, Kerocythere reticulata Kristan-Tollmann, 1972; K, lateral view of a left valve, BE18 (GeoZS6184); L, lateral view of a right valve, BE18 (GeoZS6185); M, lateral view of a right valve, BE18 (GeoZS6186); N, O, Kerocythere tuvalica Kozur, 1971; N, lateral view of a left valve, BE17 (GeoZS6187); O, lateral view of a left valve, BE21 (GeoZS6188); P, Q, Kerocythere sp. 1; P, lateral view of a right valve, BE21 (GeoZS6189); Q, lateral view of a right valve, BE21 (GeoZS6190); R, S, Simeonella daginikella Forel in Forel et al. 2019; R, lateral view of a right valve, BE18 (GeoZS6191); S, lateral view of a right valve, BE18 (GeoZS6192); T, U, Renngartenella sanctaecrucis Kristan-Tollmann in Kristan-Tollmann & Hamedani, 1973; T, lateral view of a right valve, A-1, BE2 (GeoZS6193); U, lateral view of a right valve, A-1, BE2 (GeoZS6194). Scale bars: 100 μm.

FIG. 8. — Ostracods from the Belca section,Karavanke Mountains, northwestern Slovenia,Carnian,Late Triassic.All specimens are deposited in the micropalaeontology collections of the Geological Survey of Slovenia, under the numbers GeoZS6132 to GeoZS6239, preceded by sample number: A-E, Renngartenella sanctaecrucis Kristan-Tollmann in Kristan-Tollmann & Hamedani, 1973; A, lateral view of a right valve, BE2 (GeoZS6195); B, lateral view of a left valve, BE2 (GeoZS6196); C, lateral view of a right valve, BE2 (GeoZS6197); D, lateral view of a left valve, BE2 (GeoZS6198); E, lateral view of a right valve, BE2 (GeoZS6199); F, Hungarella sp. 1, lateral view of a right valve, BE18 (GeoZS6200); G, Hungarella sp. 2, lateral view of a right valve, BE18 (GeoZS6201); H, Cardobairdia? sp., right lateral view of a complete carapace, BE17 (GeoZS6202); I-U, Issacharella bisulcata Kozur, 1972 emend. Kristan-Tollmann in Kristan-Tollmann et al. 1991b; I, lateral view of a right valve, BE18 (GeoZS6203); J, lateral view of a left valve, A-5, BE21 (GeoZS6204); K, lateral view of a right valve, A-4, BE2 (GeoZS6205); L, lateral view of a left valve,A-4,BE2 (GeoZS6206);M, lateral view of a right valve,BE2 (GeoZS6207);N, lateral view of a right valve,BE18 (GeoZS6208);O, lateral view of a left valve,A-3, BE2 (GeoZS6209); P, left lateral view of a carapace,A-2, BE17 (GeoZS6210); Q, lateral view of a right valve, BE21 (GeoZS6211); R, lateral view of a left valve, A-1, BE17 (GeoZS6212); S, lateral view of a right valve, A-1, BE2 (GeoZS6213); T, left lateral view of a carapace, Adult, BE17 (GeoZS6214); U, lateral view of a left valve, Adult, BE18 (GeoZS6215). Scale bars: 100 μm.

FIG. 3. — Distribution of ostracod species through the Belca section, Karavanke Mountains, northwestern Slovenia.

FIG. 9. — Height/Length scatter plots of Renngartenella sanctaecrucis Kristan-Tollmann in Kristan-Tollmann & Hamedani, 1973. The dimensions of right and left valves of complete carapaces are linked.