Bairdia grotei Chitnarin, 2017

Chitnarin, Anisong, Crasquin, Sylvie, Forel, Marie-Béatrice & Tepnarong, Prachya, 2017, Ostracods (Crustacea) of the Early-Middle Permian (Cisarulian-Guadalupian) from Central Thailand (Indochina Block): Part II, Orders Podocopida, Platycopida and Myodocopida, Geodiversitas 39 (4), pp. 651-690 : 660-662

Bairdia grotei Chitnarin , n. sp.

( Figs 7 A-F; 8)

Bairdia sp. 1 – Crasquin et al. 2010b: 25, pl. 1, fig. 23. n. syn.

TYPE MATERIAL. — Holotype: one complete carapace (SUT-09- 2206, Fig. 7F ); paratypes: two complete carapaces (SUT-09-2189, Fig. 7B and SUT-09-2195, Fig. 7E ).

ETYMOLOGY. — In honour of Dr Paul J. Grote, Suranaree University of Technology, Thailand.

MATERIAL EXAMINED. — 11 complete carapaces.

DIMENSIONS. — H = 0.35-0.45 mm, L = 0.62-0.74 mm, H/L = 0.57- 0.61, Holotype: H = 0.636 mm, L = 1.07mm; Paratype ( Fig. 7B ): H = 0.45 mm, L = 0.706; Paratype ( Fig. 7E ): H = 0.45 mm, L = 0.74 mm ( Fig. 8).

TYPE HORIZON. — Sample 07 PB 04-2, Nong Phai section, Pha Nok Khao Formation, Asselian-Sakmarian, Early Permian.

TYPE LOCALITY. — Nong Phai section (16°01’06’’N, 100°58’59’’E), Phetchabun Province, central Thailand.

OCCURRENCES. — Jadar Block, NW Serbia, latest Permian. Samples 07 PB04-2 and 07 PB04-5 , Nong Phai section, Pha Nok Khao Formation , Phetchabun Province, Early Permian, Central Thailand ; samples 07LB05-A1, 07LB05-B2, 07LB05-D2, Ta Kli section, Nakhon Sawan Province, Middle Permian, Central Thailand ; sample 07LB04-17, Phu Lam Yai section, Tak Fa Formation , Nakhon Sawan Province, Early Permian?, Central Thailand ; sample 07LB09-1, Khao Phu Chongkho section, Tak Fa Formation , Nakhon Sawan Province, Middle Permian, Central Thailand ; sample 08LO02-11, Tham Nam Maholan section, Nam Maholan Formation , Loei Province, Early Permian, Northeastern Thailand ; 08LO07-1, Sak Chai Quarry section, Nam Maholan Formation , Loei Province, Early Permian, Northeastern Thailand .

DIAGNOSIS. — Species of Bairdia whith spindle shape, PB located at lower 30% of H, AB located at 75% of H, PDB long and parallel to AVB, H/L = 0.57-0.61.

DESCRIPTION

Carapace spindle-shaped; dorsal outline broadly arched, maximum of convexity of AB at upper 30% of H, of PB below lower fourth of H; DB straight and slightly inclined backward (10°); ADB straight, angle with DB of 130°; AB rounded with medium radius of curvature, maximum convexity located above mid H; AVB long and nearly straight, angle between AVB and VB is 140°; VB straight at LV, slightly concave at RV; PVB long, slightly convex; PB rounded with small radius of curvature, maximum convexity located below lower fourth of H; PDB long and straight, parallel to AVB; angle between PDB and DB of 150°; LV slightly overlaps RV all around the carapace, overlap moderate at DB and ADB.

REMARKS Bairdia grotei Chitnarin , n. sp. can be compared to B. gaelleae Crasquin,2010 from the latest Permian of Meishan, South China ( Crasquin et al. 2010a) in lateral view; however here the AB has a smaller radius of curvature and ADB and DB are straighter.

Bairdia cf. fangnianqiaoi Crasquin, 2010 ( Fig. 7 G-L)

Bairdia cf. fangnianqiaoi Crasquin in Crasquin et al., 2010a: 342, 344, fig. 9K-N.

MATERIAL EXAMINED. — 13 complete carapaces.

OCCURRENCES. — Sample 07 PB04-2 , Nong Phai section, Pha Nok Khao Formation , Phetchabun province, Early Permian, Central Thailand ; samples 07LB05-3, 07LB05-4, 07LB05-B3, 07LB05-C1, Ta Kli section, Tak Fa Formation, Nakhon Sawan Province, Middle Permian, Central Thailand ; sample 08LB01-1, Khao Som Phot section, Tak Fa Formation, Lopburi Province, Middle Permian, Central Thailand .

DIMENSIONS. — H = 0.20-0.60 mm, L = 0.60-1.07 mm, H/L = 0.36-0.43.

REMARKS

The specimens recovered are very similar to Bairdia fangnianqiaoi Crasquin, 2010 from the latest Permian of Meishan section ( Crasquin et al. 2010a) in lateral view but can be differentiated by a smaller H/L ratio and regularly arched dorsal outline at LV.

Figures

FIG. 7. — Ostracods from Indochina Block, Central Thailand.All specimens are stored at the Suranaree University of Technology Collections (Nakhon Ratchasima, Thailand) numbers SUT-09-xxxx. All the specimens are complete carapaces in right lateral view. A-F, Bairdia grotei Chitnarin, n. sp.; A, SUT-09-2188, sample 07PB04-2; B, paratype, SUT-09-2189, sample 07PB04-2; C, SUT-09-2192, sample 07LB05-B2; D, SUT-09-2203, sample 07PB04-2; E, paratype, SUT-09-2204, sample 08LO07-1; F, holotype, SUT-09-2206, sample 08LO02-11. G-L, Bairdia cf. fangnianqiaoi Crasquin, 2010; G, SUT-09-2260, sample 07LB05-4; H, SUT- 09-2263, sample 08LB01-1; I, SUT-09-2261, sample 07LB05-B3; J, SUT-09-2270, sample 07LB05-B3; K, SUT-09-2271, sample 07PB04-2; L, SUT-09-2279, sample 07PB04-2. M-O, Bairdia cf. B.? mianyangensis Chen, 1982; M, SUT-09-2254, sample 07PB03-3; N, SUT-09-2252, sample 07PB03-3; O, SUT-09-2250, sample 07PB03-3. Scale bars: 100 µm..