Bairdia jeancharlesi Forel, 2011

Forel, Marie-Béatrice & Crasquin, Sylvie, 2011, In the aftermath of Permian-Triassic boundary mass-extinction: new ostracod (Crustacea) genus and species from South Tibet, Geodiversitas 33 (2), pp. 247-263 : 250-253

Bairdia jeancharlesi Forel n. sp. ( Fig. 3 I-L)

TYPE MATERIAL. — Holotype: one complete carapace (P6M2607; Fig. 3J ); paratype: one complete carapace (P6M2603; Fig. 3I ).

ETYMOLOGY. — Dedicated to Jean-Charles Forel, personal dedication.

MATERIAL EXAMINED. — 26 complete carapaces and 1 single valve.

DIMENSIONS. — L = 435 to 1120 µm; H = 260 to 680 µm. Holotype: L = 453 µm; H = 276 µm. Paratype: L = 895 µm; H = 535 µm.

TYPE HORIZON. — Sample 06Ti08, unit IIIb, Tulong Formation, Smithian, Lower Triassic.

TYPE LOCALITY. — Tulong section, Southern Tibet .

OCCURRENCE. — Tulong section, southernTibet.Samples 06Ti04, 06Ti08, 06Ti21, 06Ti27-31, 06Ti35, Tulong Formation, units III, V and VI, Smithian to Anisian, Lower-Middle Triassic.

DIAGNOSIS. — A punctate species of Bairdia with faint overlap, AB and PB with quite small radius of curvature, PDB, BD and ADB straight at RV.

DESCRIPTION

RV: PDB, DB and ADB straight; AB regularly arched with maximum of curvature located in its middle; AVB and PVB regularly convex; VB concave

complete carapace (P6M2599); F -H, Bairdia finalyi ( Méhes, 1911) ; F, right lateral view of a complete carapace (P6M2601); G, right lateral view of a complete carapace (P6M2602); H, right lateral view of a complete carapace (P6M2606); I -L, Bairdia jeancharlesi Forel n. sp.; I, paratype (P6M2603), right lateral view of a complete carapace; J, holotype (P6M2607), right lateral view of a complete carapace; K, right lateral view of a broken carapace (P6M2604); L, right lateral view of a complete carapace (P6M2605); M, Spinocypris vulgaris Kozur, 1971 , right lateral view of a complete carapace (P6M2600). Scale bars: 100 μm.

TABLE 1 . — Distribution chart and abundances of Lower and Middle Triassic ostracods in the Tulong section. The global extension of each species within the section is represented with grey parts. Abundances are indicated as follows: z, between 1 and 5 specimens ; Ƃ, between 5 and 10 specimens; ¡, between 10 and 20 specimens; ×, more than 20 specimens.

in its anterior part; PB with quite small radius of curvature but bairdoid beak poorly expressed. LV: PDB straight, DB regularly arched, ADB straight to gently arched, AB rounded with maximum of curvature in its middle; AVB, VB and PVB arched; PB with quite small radius of curvature. Carapace ornamented by small punctations, flattened laterally in posterior and anterior parts; overlap is small with maximum in anterior part of DB; H/L = 0.61.

REMARKS

Bairdia jeancharlesi Forel n. sp. is close to Bairdia cassiana rotundidorsata Monostori, 1995 from the Anisian of Balaton area ( Hungary; Monostori 1995). Here, the carapace is shorter, the overlap is weaker and the DB and PDB are more inclined posteriorly.

Figures

FIG. 3. — Specimens from Tulong section (Tibet), stored at the Pierre et Marie Curie University Collections (Paris,France):A-E, Bairdia letangae Forel n. sp.; A, holotype (P6M2595), right lateral view of a complete carapace; B, paratype (P6M2596), right lateral view; C, right lateral view of a broken carapace (P6M2597); D, right lateral view of a broken carapace (P6M2598); E, left lateral view of a