Bairdia cf. calida Chen, 1958

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 : 664

Bairdia cf. calida Chen, 1958

( Fig. 10A, B )

Bairdia calida Chen, 1958: 243 , pl. IV, figs 9-15.

MATERIAL EXAMINED. — One complete and two incomplete carapaces.

OCCURRENCES. — Sample 07 PB03-7 , Khao Kana section, Pha Nok Khao Formation, Phetchabun province, Central Thailand, Early Permian ; sample 07 PB05-3 , Ban Naen Sawan I section, Pha Nok Khao Formation, Phetchabun province, Central Thailand, Middle Permian .

DIMENSIONS. — H = 0.715 -0.747 mm, L = 1.22-1.33 mm, H/L = 0.56-0.58.

REMARKS

The specimens are close to Bairdia calida Chen, 1958 from the Early Permian of Jiangsu Province, Eastern China ( Chen 1958) which is characterized by a narrow ventral ridge on RV and the dorsal ridge on LV. In our specimens, the ventral ridge on RV is observed; though, the dorsal ridge on LV is not recognized.

Bairdia cf. zhongyingensis Wang, 1978 ( Fig. 9D )

Bairdia zhongyingensis Wang, 1978: 16 , pl. III, fig. 2a-c.

MATERIAL EXAMINED. — One complete carapace.

OCCURRENCES. — Sample 07LB05-A2, Ta Kli section, Tak Fa Formation, Nakhon Sawan Province, central Thailand, Middle Permian.

DIMENSIONS. — H = 0.712 mm, L = 1.31 mm, H/L = 0.54.

REMARKS

The specimen resembles Bairdia zhongyingensis Wang, 1978 from the Late Permian of South China ( Wang 1978) in lateral outline, especially for the small radius of curvature of AB, small radius of curvature of PB and concave VB; however, radius of curvature of AB of our specimen is largerand higher and the overlap of LV on RV is not clear.

Bairdia beedei Ulrich & Bassler, 1906 ( Fig. 10C, D )

Bairdia beedei Ulrich & Bassler, 1906: 161 , pl. XI, figs 19, 20. — Chen 1958: 249, pl. 5, figs 1-4.

MATERIAL EXAMINED. — Five complete carapaces.

OCCURRENCES. — Kwanshan and Lungtan sections, Jiangsu Province, Early Permian ( Chen 1958); samples 07 PB 03-1, 07 PB 03-7, Khao Kana section, Pha Nok Khao Formation, Phetchabun Province, Early Permian; sample 07 PB 04-2, Nong Phai section, Pha Nok Khao Formation, Phetchabun Province, Central Thailand, Early Permian.

DIMENSIONS. — H = 0.49-0.86 mm, L = 0.82-1.13 mm, H/L = 0.54-0.57.

REMARKS

Our specimens have elongate, subfusiform carapace in lateral view with strong overlap of LV on RV at DB. DB of RV is steeply arched, DB of LV is straight and the VB is broadly convex. The carapaces of the studied specimens are longer than Bairdia beedei Ulrich & Bassler from Late Carboniferous of North America ( Ulrich & Bassler 1906).

Figures

FIG. 10. — 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, B, Bairdia cf. calida Chen, 1958; A, SUT- 09-2127, sample 07PB03-7; B, SUT-09-2128, sample 07PB25-3; C, D, Bairdia beedei Ulrich & Bassler, 1906; C, SUT-09-2685, sample 07PB03-3; D, SUT- 09-2687, sample 07PB04-2; E, F, Bairdia altiarcus Chen, 1958; E, SUT-09-2105, sample 07LB05-D2; F, SUT-09-2101, sample 07LB05-D3; G, H, Bairdia trianguliformis Chen, 1958; G, SUT-09-2318, sample 08LO07-10; H, SUT-09-2319, sample 08LO07-1; I, Kempfina cf. qinglaii (Crasquin, 2008), SUT-09-2533, sample 07PB03-7; J, Bairdia sp. D SUT-09-2300, sample 07LB09-2; K, Bairdia sp. E, SUT-09-2301, sample 08LO02-10; L, Bairdia sp. F, SUT-09-2311, sample 07LB05-5; M, N, Bairdia sp. G; M, SUT-09-2307, sample 07PB04-2; N, SUT-09-2306, sample 07PB04-2; O, Bairdia sp. H, SUT-09-2310, sample 07PB05-6. Scale bars: 100 µm.

FIG. 9. — 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 represented by complete carapaces. A-C, Bairdia guangxiensis Guan, 1978; A, right lateral view, SUT-09-2207, sample 07PB07-4; B, left lateral view, SUT-09-2208, sample 07PB06-3; C, ventral view, SUT-09-2213, sample 07PB07-3. D, Bairdia cf. zhongyingensis Wang, 1978 sensu Chen & Bao, 1986; right lateral view, SUT-09-2339, sample 07LB05-A2; E, F, Bairdia bassoni Crasquin, 2010; E, right lateral view, SUT-09-2117,sample 07PB03-3; F, right lateral view,SUT-09-2118,sample 07PB03-3;G-J, Bairdia urodeloformis Chen, 1987;G, right lateral view,SUT-09-2332, sample 08LB01-1; H, right lateral view, SUT-09-2325, sample 07LB05-5; I, right lateral view, SUT-09-2335, sample 08PB05-3; J, right lateral view, SUT-09-2338, sample 07LB05-5; K-M, Bairdia cf. urodeloformis Chen, 1987; K, right lateral view, SUT-09-2151, sample 07LB05-B2; L, right lateral view, SUT-09-2152, sample 07LB05-3; M, right lateral view, SUT-09-2156, sample 08LO02-2; N-P, Bairdia sp. A; N, right lateral view, SUT-09-2285, sample 07PB04-2; O, right lateral view, SUT-09-2291, sample 07PB04-2; P, right lateral view, SUT-09-2290, sample 07PB04-2. Scale bars: 100 µm.