Leviella bogschi Kozur, 1972

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 : 395

Leviella bogschi Kozur, 1972

( Fig. 11 A-J)

Leviella bogschi Kozur, 1972: 20, pl. 1, fig. 4; pl. 2, figs 1-7. — Kristan-Tollmann et al. 1991b: 206, pl. 3, figs 1, 3.

EXAMINED MATERIAL. — More than 100 specimens, including isolated valves and complete carapaces.

OCCURRENCE. — Carnian, Late Triassic, Veszprem, Balatón highland, Hungary (Kozur 1972); Carnian, Late Triassic,Transdanubian range, Hungary (Kristan-Tollmann et al. 1991b); Nicoraella ? budaensis conodont zone, late Julian-?earliest Tuvalian, Carnian, Late Triassic, samples BE2, 17, 18, 21, 23/1 ( Fig. 3 ), Belca section, ‘Raibl Beds’, Karavanke Mountains, Slovenia (this work).

DIMENSIONS. — Fig. 12.

DISCUSSION

Leviella bogschi Kozur, 1972 has been found in all samples of the Belca section. It is rare in samples BE2 and BE23/1 but is moderately abundant in samples BE17 to BE21 ( Fig. 3 ). This species is another species typical of the Carnian that was only known from Hungary until the Belca record. The dispersal of the sizes of both left and right valves in Belca is the largest observed until now for this species, with the smallest known specimens and the largest documented left valve. Kristan-Tollmann et al. (1991b) stated that the holotype of this species described by Kozur (1972) is not a mature stage: this observation is confirmed with the specimens from Belca, for both valves ( Fig. 12 ). Until now, three complete carapaces of L. bogschi are known to science [one from Kozur (1972), two from this work]. The gaps between the successive scatter plots in L. bogschi are well marked and allow the distinction of six ontogenetic stages for the left valves (A-5 to Adult) and seven for the right valves (A-6 to Adult). In early juveniles, the valves are very assymetric with narrow posterior end and weakly developed lateral ridges. The ontogenetic development of L. bogschi is marked by the progressive enlargement of the posterior end of the carapaces and strengthening of the lateral ridges and sulcus. The three carapaces known from this species belong to the Adult, A-1 and A-5 stages ( Fig. 12 ). Although rare, these carapaces show that the overlap of RV over LV occurs as early as A-5 and increases through the ontogenetic development.

Figures

FIG. 11. — 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-J, Leviella bogschi Kozur, 1972; A, left lateral view of a carapace, A-1, BE21 (GeoZS6216); B, lateral view of a left valve, A-1, BE18 (GeoZS6217); C, lateral view of a left valve, A-2, BE18 (GeoZS6218); D, lateral view of a right valve, A-2, BE18 (GeoZS6219); E, lateral view of a left valve,A-3, BE18 (GeoZS6220); F, lateral view of a right valve, A-3, BE18 (GeoZS6221); G, lateral view of a right valve, A-3, BE18 (GeoZS6222); H, left lateral view of a carapace, A-5, BE21 (GeoZS6223); I, lateral view of a right valve, A-5, BE17 (GeoZS6224); J, lateral view of a right valve, A-6, BE18 (GeoZS6225); K-T, Leviella veghae Kozur, 1972; K, lateral view of a left valve, A-5, BE18 (GeoZS6226); L, lateral view of a right valve, A-5, BE18 (GeoZS6227); M, left lateral view of a carapace, A-4, BE21 (GeoZS6228); N, lateral view of a right

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

FIG. 12. — Height/Length scatter plots of Leviella bogschi Kozur, 1972. The dimensions of right and left valves of complete carapaces are linked.