Dayia bohemica Bouček, 1941

Baliński, Andrzej, 2012, The brachiopod succession through the Silurian-Devonian boundary beds at Dnistrove, Podolia, Ukraine, Acta Palaeontologica Polonica 57 (4), pp. 897-924 : 920

Dayia bohemica Bouček, 1941

Fig. 19A–C .

1847 Terebratula navicula Murch. ; Barrande 1847: 402, pl. 15: 4.

1879 Atrypa navicula Sow. ; Barrande 1879: pls. 17−I: 1–7; 28−II: 1–16.

1929 Dayia navicula (Sowerby) ; Kozłowski 1929: 179–181, pl. 5: 22; fig. 59.

1941 Dayia navicula bohemica (nov.); Bouček 1941: 14, pl. 2: 1.

1977 Dayia bohemica Bouček, 1940 ; Rubel 1977: 215, pl. 3, 4; fig. 3.

1982 Dayia bohemica Bouček, 1940 ; Modzalevskaya and Nikiforova 1982: 111, pl.1: 22.

1990 Dayia bohemica Bouček, 1941 ; Havlíček and Štorch 1990: 206, pl. 68: 9–11.

Material.—34 complete or slightly damaged shells and about 130 fragmentary specimens. The species occurs in the lowermost exposed there layers, i.e., 1.3–1.6 metres below the S –D boundary (beds −21 to −24).

Remarks.— Dayia bohemica was initially proposed by Bouček (1941) as a new subspecies of D. navicula . Subsequently, however, it has been elevated to the species rank by Rubel (1977) and Havlíček and Štorch (1990).

According to Nikiforova et al. (1985), the specimens from the Dzwinogorod Beds near Dnistrove described by Kozłowski (1929) and Nikiforova (1954) as Dayia navicula (Sowerby, 1839) represent Dayia bohemica Bouček, 1941 , which is known from approximately contemporaneous beds in the Pridoli of Bohemia. In addition to D. bohemica, Nikiforova et al. (1985: 45) also reported the occurence of typical D. navicula in slightly older horizons in Podolia, in the Grinchuk and Isakovtsy beds.

Stratigraphic and geographic range.—The species is known from several sections of the Pridoli Formation in Bohemia ( Havlíček and Štorch 1990). Rubel (1977) reported it from Pridoli of Estonia, Lithuania, and Latvia. In Podolia the species was reported from the Dzvenyhorod Beds of the Skala Horizon from the vicinity of Dzvenyhorod and Dnistrove villages.

Figures

Fig. 19. Athyridide brachiopods from the Silurian–Devonian boundary beds at Dnistrove (Podolia, Ukraine). A–C. Dayia bohemica Bouček, 1941; three shells, ZPAL Bp. 56/200 (A), ZPAL Bp. 56/201 (B), and ZPAL Bp. 56/202 (C), in dorsal (A1, B1, C1), ventral (A2, B2, C2), lateral (A3, B3, C3), posterior (A4, B4, C4), and anterior (A5, B5, C5) views. D–F, J. Dnestrina gutta Nikiforova and Modzalevskaya, 1968. D, E. Two shells, ZPAL Bp. 56/208 (D) and ZPAL Bp. 56/209 (E), in dorsal (D1, E1), ventral (D2, E2), lateral (D3, E3), posterior (D4, E4), and anterior (D5, E5) views. F. Interior view of slightly damaged ventral valve, ZPAL Bp. 56/210. J. Shell ZPAL Bp. 56/207b in dorsal exterior view. G, H. Pseudoprotathyris infantilis (Kozłowski, 1929); two shells, ZPAL Bp. 56/176 (G) and ZPAL Bp. 56/177 (H), in dorsal (G1, H1), ventral (G2, H2), lateral (G3, H3), posterior (G4, H4), and anterior (G5, H5) views. I. Camarium sp.; shell ZPAL Bp. 56/29 in dorsal (I1), ventral (I2), lateral (I3), posterior (I4), and anterior (I5) views. Beds −24 (A–C), −21 (D–F, J), −4 (G, H), and 47–48 (I). Scale bars 2 mm.