Ostracods from the ‘ Raibl Beds’ (Carnian, Late Triassic) of Belca section in Karavanke Mountains, northwestern Slovenia
Author
Forel, Marie-Béatrice
Author
Kolar-Jurkovšek, Tea
Author
Jurkovšek, Bogdan
text
Geodiversitas
2020
2020-09-10
42
21
377
407
journal article
8555
10.5252/geodiversitas2020v42a21
bbf04a36-7745-4cd9-88dd-a82d65f2d04f
1638-9395
4447609
urn:lsid:zoobank.org:pub:7EC0E4FA-D538-4CE2-91B8-D7F549C32985
Bairdia cassiana
(
Reuss, 1869
)
(
Fig. 4
F-H)
Cythere cassiana
Reuss, 1869: 108
.
Bairdia cassiana
– Gümbel 1869: 180, pl. 5, figs 18, 19. —
Styk 1958: 171
, fig. 3/1. —
Urlichs 1970: 705
, 706, pl. 1, figs 1, 2. — Kristan-Tollmann 1978: 81, pl. 1, fig. 4; pl. 6, fig. 6. — Kristan-Tollmann
et al.
1991b: 200, pl. 1, fig. 5. —
Monostori & Tóth 2013: 310
, pl. 2, figs 7, 8, 10; 2014: 26, pl. 1, fig. 14. —
Mette
et al.
2014
: pl. 2, fig. 1. — Crasquin
et al
. 2018: 134, fig.
6M.
Bairdia cassiana rotundidorsata
Monostori, 1995: 42
, pl. 2, figs 4, 5.
Bairdia
(
Rectobairdia
)
garciai
Crasquin-Soleau & Grădinaru, 1996: 77
, 78, pl. 2, figs 5, 8.
EXAMINED MATERIAL. —
Four right valves, four left valves and several fragments.
OCCURRENCE. — Early Carnian, Late Triassic, Southern Alps,
Italy
(
Reuss 1869
; Gümbel 1869;
Urlichs 1970
; Kristan-Tollmann 1978); Carnian, Late Triassic,
Święty Krzyż
Mountain,
Poland
(
Styk 1958
); Carnian, Late Triassic, Zsämbek-14 borehole,Transdanubian Range,
Hungary
(Kristan-Tollmann
et al.
1991b); Late Anisian, Middle Triassic, Balatón Highland,
Hungary
(
Monostori 1995
); Early Anisian, Middle Triassic, North Dobrogea,
Romania
(Crasquin-Soleau & Grădinaru 1996); Ladinian, MiddleTriassic, Balatón Highland,
Hungary
(
Monostori & Tóth 2013
,
2014
); Middle Anisian, Middle Triassic, Northern Calcareous Alps,
Austria
(
Mette
et al.
2014
);
Tropites dilleri
zone, late Carnian, Late Triassic,
Sicily
,
Italy
(Crasquin
et al.
2018);
Nicoraella
?
budaensis
conodont zone, late Julian-?earliest Tuvalian, Carnian, Late Triassic, samples BE17, 18, 21, 23/1 (
Fig. 3
), Belca section, ‘Raibl Beds’, Karavanke Mountains,
Slovenia
(this work).
DIMENSIONS. —
Fig. 5B.
DISCUSSION
Bairdia cassiana
(
Reuss, 1869
)
has been found in all samples from BE17 to BE23/1 where it is not abundant, and it is moderately abundant in BE18 (
Fig. 3
).
Bairdia cassiana
is typical of the Middle and early Late Triassic of Europe, as shown by the synonym list. The height/length scatter plot of all Carnian specimens is shown in
Fig. 5B
(the dimensions of the specimens cited without mention of their nature, i.e. right valve, left valve or carapace, have been omitted). The largest specimens are from the Ladinian of
Hungary
(
Monostori & Tóth 2013
,
2014
). The separate measurements of right and left valves of complete carapaces show that the degree of overlap is relatively constant during the ontogeny of this species. The left valve is slightly longer than the right valve in the first instars compared to later stages. The ontogenetic development of
B. cassiana
is also marked by the elongation of the posterior border.