Basslerella naresi 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 : 682

Basslerella naresi Chitnarin , n. sp.

( Figs 27 F-J; 29)

TYPE MATERIAL. — Holotype, one complete carapace (SUT-09- 2463, Fig.27G ); paratypes, two complete carapaces (SUT-09-2486, Fig. 27F and SUT-09-2477, Fig. 27J ).

ETYMOLOGY. — In honour of Mr Nares Sattayalak, PTTEP, Thailand.

MATERIAL EXAMINED. — 21 complete carapaces.

DIMENSIONS. — H = 0.20-0.56 mm, L = 0.30-0.83 mm, H/L = 0.64- 0.74, Holotype: H = 0.50 mm, L = 0.77 mm; Paratype ( Fig. 27F ): H = 0.40, L = 0.61 mm; Paratype ( Fig. 27J ): H = 0.42 mm, L = 0.67 mm ( Fig. 29).

TYPE HORIZON. — Sample number 08LO02-2, Tham Nam Maholan section, Nam Maholan Formation, Asselian, Early Permian.

TYPE LOCALITY. — Sample 08LO02-2, Tham Nam Maholan section (17° 06’ 23’’N, 101° 52’48’’E), Nam Maholan Formation, Loei province, northeastern Thailand.

OCCURRENCES. — Samples 08LO02-1, 08LO02-2, Tham Nam Maholan section, Nam Maholan Formation, Loei province, northeastern Thailand, Early Permian ; samples 07LB05-B1, 07LB05-B2, 07LB05-A2, 07LB05-5, Ta Kli section, Tak Fa Formation, Nakhon Sawan province, central Thailand, Early Permian .

DIAGNOSIS. — Species of Basslerella with long carapace, straight and long DB, AB and PB maximum of curvature located below mid H, and very wide and flat ventral area, dorsal view with water drop aspect.

DESCRIPTION

Carapace long, subelliptical; dorsal outline broadly arched; DB straight, inclined at 30° rearward; ADB slightly convex; PDB short, forming an angle of 135° with DB; AB rounded with large radius of curvature, maximum convexity located, at lower third of H; AVB short and convex; VB straight; ventral area flat; PVB short and convex; PB blunt, located just above VB; greatest H located at just in front of mid L; surface smooth; LV larger and slightly overlaps RV all around the carapace; carapace with water drop aspect in dorsal view, maximum thickness in the posterior part.

REMARKS

Basslerella naresi Chitnarin , n. sp. can be recognized very easily by its very wide and flat ventral area. Larger specimens have the wider and thicker posterior part and ADB rounded. B. naresi Chitnarin , n. sp. can be differentiated from B. annesophieae from the latest Permian of Meishan section, Eastern China ( Crasquin et al. 2010a: 362, 363, figs 20N-V) by the smaller radius of curvature of AB and the longer carapace.

Figures

FIG. 27. — Ostracods from the limestones of the 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, except K and L, are represented by complete carapaces. A-E, Basslerella wipanuae Chitnarin, n. sp.; A, holotype, right lateral view, SUT-09-2429, sample 07PB03-5; B, paratype, left lateral view, SUT-09-2430, sample 07PB03-5; C, ventral view, SUT-09-2426, sample 07PB04-2; D, paratype, right lateral view, SUT-09-2421, sample 07PB03-5; E, right lateral view, SUT-09-2425, sample 07PB04-2. F-J, Basslerella naresi Chitnarin,n. sp.; F, left lateral view,SUT-09-2486,sample 08LO02-1; G, holotype,left lateral view,SUT-09-2463,sample 08LO02-2;H, ventral view, SUT-09-2462, sample 08LO02-2; I, left lateral view, SUT-09-2461, sample 08LO02-2; J, left lateral view, SUT-09-2477, sample 07LB05-A2. K, L, Polycope sp.; K, SUT-09-2604, sample 07PB06-5; L, SUT-09-2606, sample 07PB06-5. M-P, Polycope sp.A; M, left lateral view, SUT-09-2610, sample 07PB04-2; N, left lateral view, SUT-09-2621, sample 08LO02-2;O, anterior view,SUT-09-2615,sample 07PB04-2;P, left lateral view, SUT-09-2627, sample 07LB05-B2.Q, R, Polycope sp. B; Q, left lateral view, SUT-09-2628, sample 08LO02-5; R, left lateral view, SUT-09-2630, sample 08LO02-5. S-U, Polycope sp.C; S, left lateral view, SUT-09-2644, sample 07LB09-1; T, left lateral view, SUT-09-2643, sample 07LB09-1; U, left lateral view, SUT-09-2642, sample 07LB09-1. Scale bars: 100 μm.