In the aftermath of Permian-Triassic boundary mass-extinction: new ostracod (Crustacea) genus and species from South Tibet
Author
Forel, Marie-Béatrice
Author
Crasquin, Sylvie
text
Geodiversitas
2011
2011-06-30
33
2
247
263
http://dx.doi.org/10.5252/g2011n2a3
journal article
7715
10.5252/g2011n2a3
52b03d71-cefc-44da-9b75-e7cc270ed280
1638-9395
4597109
790AC12D-10AA-4480-AD5B-BAA1A543C552
Bairdia letangae
Forel
n. sp.
(
Fig. 3
A-E)
TYPE MATERIAL
. —
Holotype
: one complete carapace (P6M2596;
Fig. 3A
);
paratype
: one complete carapace (P6M2595;
Fig. 3B
).
ETYMOLOGY. — Dedicated to Béatrice Letang, personal dedication.
MATERIAL
EXAMINED. — 7 complete carapaces and 2 single valves.
DIMENSIONS. — L =
540-785 µm
; H =
320-500 µm
.
Holotype
: L =
785 µm
; H =
492 µm
.
Paratype
: L =
540 µm
; H =
320 µm
.
TYPE
HORIZON
. — Sample 06Ti30, unit
VI
, Tulong Formation, Early Anisian, Middle Triassic.
TYPE
LOCALITY
. — Tulong section, Southern
Tibet
.
OCCURRENCE. — Tulong section, Southern
Tibet
. Samples 06Ti21, 06Ti30, 06Ti31 and 06Ti34, Tulong Formation, units
V
and
VI
, Spathian-Anisian, Early-Middle Triassic.
DIAGNOSIS. A massive species of ornamented
Bairdia
with AB and PB flattened, large reticulation on all the carapace except the dorsal margin.
DESCRIPTION
At RV, PDB straight, DB long and more or less horizontal, ADB straight to gently concave. At LV all dorsal parts form a regular arch. AB with quite small radius of curvature; AVB and PDB regularly arched; VB straight at LV, gently concave RV; PB with medium radius of curvature; maximum of curvature of PB and AB located at the same H; carapace strongly compressed along free margins and particularly in AB and PB; surface ornamented by a large reticula-
tion, this reticulation is present on all the surface except for dorsal margins of both valves.
REMARKS
Bairdia letangae
Forel
n. sp.
is similar to
Bairdia ortiseiensis
Crasquin, 2008
from the Late Permian of the Tesero section (Northern
Italy
;
Crasquin
et al.
2008
). Here the DB is longer, the radius of curvature of AB is more important and the overlap is stronger. Compared to
Lobobairdia zapfei
Kozur, 1971
from the Anisian of Balaton area (
Kozur 1971
;
Monostori 1995
),
Bairdia letangae
Forel
n. sp.
has a straighter DB and reticulation present all over the carapace surface.