Acratia chongpani 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 : 675-676

Acratia chongpani Chitnarin , n. sp.

( Figs 21 A-G; 22)

Acratina guseva e Kozur, 1985b: 104, pl. 20, fig. 1. — Crasquin- Soleau & Baud 1998: pl. 3, fig. 1. n. syn.

TYPE MATERIAL. — Holotype, one complete carapace (SUT-09- 2006, Fig.21A ); paratypes, two complete carapaces (SUT-09-2001, Fig. 21E and SUT-09-2013, Fig. 21F ).

ETYMOLOGY. — In honour of Dr Chongpan Chonglakmani, Thailand.

MATERIAL EXAMINED. — 51 complete carapaces.

DIMENSIONS. — H = 0.25-0.51 mm, L = 0.66-1.18 mm, H/L = 0.43- 0.53, Holotype: H = 0.73 mm, L = 1.08 mm; Paratype ( Fig. 21F ): H = 0.42 mm, L = 0.60 mm; Paratype ( Fig. 21E ): H = 0.58 mm, L = 0.90 mm ( Fig. 22).

TYPE HORIZON. — Sample 07LB05-6, Ta Kli section, Tak Fa Formation, Early Permian.

TYPE LOCALITY. — Ta Kli section (15°19’05’’N, 100°22’46’’E), Tak Fa Formation, Nakhon Sawan Province, central Thailand.

OCCURRENCES. — Hydra Island , Greece, late Middle Permian (Crasquin-Soleau & Baud 1998) ; sample 08LO07-3, Sak Chai section, Pha Nok Khao Formation, Chiyaphum Province, northeast Thailand, Early Permian ; samples 07 PB03-2 , 07 PB03-3 and 07 PB03-5 , Khao Kana section, Pha Nok Khao Formation, Phetchabun Province, central Thailand, Early Permian ; sample 07LB05-6, Ta Kli section, Tak Fa Formation, Nakhon Sawan Province, central Thailand, Early Permian ; sample 08LB01-1, Khao Som Phot section, Tak Fa Formation, Lopburi Province, central Thailand, Middle Permian .

DIAGNOSIS. — Species of Acratia with a laterally flattened, long, hook-like AB, pointing downward, and located at lower 30% of H, angle between AVB and VB is 150° and PB is located at ventral level. DESCRIPTION

Carapace long and large; dorsal outline broadly arched; DB slightly convex on LV, straight on RV which gently inclined rearward at 15-20°; ADB convex and with an angle of 140° with DB; PDB convex and with an angle of 140° with DB; AB of a hook-like shape, maximum convexity located at lower third of H, AB flattened laterally; AVB long and making an angle of 150°with VB; VB straight to slightly concave; ventral area flat; PVB short in extension of VB; PB bluntly round and located at VB; maximum H located in front of mid L; surface smooth; LV larger and overlapping RV at ADB and PDB; carapace subfusiform in dorsal view.

REMARKS

Acratia chongpani Chitnarin , n. sp. can be compared to A. praetypica Posner, 1951 from the Early Carboniferous of Moscow Basin, Russia ( Posner 1951: 98, pl. 21, fig. 9) in lateral outline. Differences occur at VB which is blunt in A. chongpani but raised upward in A. praetypica , and at the angle between AVB and VB which is of 150° in the former species but of 140° in the latter. Acratina guseva e Kozur sensu Crasquin-Soleau & Baud 1998 is included to A. chongpani Chitnarin , n. sp. due tothe smaller AVB and the shorter PVB than those in Acratina guseva e Kozur, 1985.

Figures

FIG. 21. — 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 are represented by complete carapaces. A-G, Acratia chongpani Chitnarin, n. sp.; A, holotype,right lateral view,SUT-09-2006,sample 07PB03-3;B, dorsal view,SUT-09-2018,sample 07PB03-5;C, ventral view,SUT-09-2042,sample 07PB03-2; D, right lateral view,SUT-09-2036,sample 07PB03-2;E, paratype,right lateral view,SUT-09-2001,sample 07PB03-5;F, paratype,right lateral view,SUT-09-2013, sample 07PB03-5; G, left lateral view, SUT-09-2020, sample 07PB03-3; H, Bairdiidae indet. sp. B, right lateral view, SUT-09-2567, sample 08LB01-2; I, Acratia sp., left lateral view, SUT-09-2055, sample 08LB01-3; J-M, Acratia mongkoli Chitnarin, n. sp.; J, ventral view, SUT-09-2067, sample 07PB04-2; K, holotype, right lateral view, SUT-09-2058, sample 07PB04-2; L, paratype, right lateral view, SUT-09-2063, sample 07LB09-1; M, paratype, right lateral view, SUT-09-2062, sample 07LB09-1; N-P, Baschkirina cf. huzhouensis Forel, 2010; N, left lateral view, SUT-09-2531, sample 08LB01-1; O, left lateral view, SUT-09-2528, sample 08LB01-1; P, right lateral view, SUT-09-2530, sample 08LB01-1. Scale bars: 100 μm.