Eurytreta minor Biernat, 1973, 2002

Holmer, Lars E. & Biernat, Gertruda, 2002, Urban and Peri-urban small and medium-size Enterprise Development for sustainable Vegetable Production and Marketing Systems, Acta Palaeontologica Polonica 47 (1), pp. 141-156 : 152-154

publication ID	https://doi.org/ 10.13140/rg.2.1.3543.9120
persistent identifier	https://treatment.plazi.org/id/FB5C1130-FFB0-593C-FCB4-D37D0976F9FA
treatment provided by	Felipe
scientific name	Eurytreta minor Biernat, 1973
status

Treatment

Eurytreta minor Biernat, 1973

Fig. 10A–K, M, O View Fig .

Eurytreta minor sp. nov.; Biernat 1973: 74, pl. 9: 1–6; fig. 26. Eurytreta minor Biernat ; Popov and Holmer 1994: 100, fig. 84 [full synonymy].

Holotype: ZPAL Bp XV /16n; ventral valve (W = 1.00, L = 0.8).

Type locality: Wysoczki. Holy Cross Mountains, Poland.

Type horizon: Tremadoc chalcedonites.

Material.—Figured ventral valve: RM Br133821; dorsal valves: RM Br133819 (W = 0.64, L = 0.51), RM Br133820 (W = 0.95, L = 0.80, WI = 0.30, LI = 0.08, WM1 = 0.63, LM1 = 0.38, LS = 0.55), RM Br133822 (W = 0.78, L = 0.68, WI = 0.26, WM1 = 0.50, LM1 = 0.30, LS = 0.40), RM Br133823, RM Br133824 (W = 1.08, L = 0.89, WI = 0.44, WM1 = 0.66, LM1 = 0.39, LS = 0.47), RM Br133825 (W = 0.74, L = 0.60, WI = 0.28). Total of 12 dorsal and 8 ventral valves.

Diagnosis.—See Popov and Holmer (1994: 100).

Description.—Shell transversely suboval, 80–87% as long as wide (N = 6). Ventral valve low conical, about 66% as high as long (N = 1). Ventral pseudointerarea procline with poorly defined intertrough. Posterior surface gently concave in lateral profile. Anterior slope of ventral valve evenly convex in lateral profile. Pedicle foramen rounded, at end of very short pedicle tube, within larval shell. Ventral apical process poorly developed, directly anterior to internal foramen.

Dorsal valve only slightly convex in lateral profile. Dorsal pseudointerarea very narrow and short, occupying 32–40% of valve width (N = 4). Median groove broadly triangular and with small propareas. Dorsal cardinal muscle field occupying around 61–66% of valve width. Median buttress variably developed. Dorsal median ridge variably developed, usually very low, extending for around 52–68% of valve length. Larval shell of both valves around 0.2 mm wide.

Discussion.—A detailed comparative discussion of this and other related species of Eurytreta was given by Popov and Holmer (1994). The new Polish material described here is morphologically identical with the material described from the Bjørkåsholmen Limestone in Scandinavia.