Pseudoprotathyris infantilis ( Kozłowski, 1929 )

Baliński, Andrzej, 2012, The brachiopod succession through the Silurian-Devonian boundary beds at Dnistrove, Podolia, Ukraine, Acta Palaeontologica Polonica 57 (4), pp. 897-924 : 919

Pseudoprotathyris infantilis ( Kozłowski, 1929)

Figs. 17 , 19G, H .

1929 Protathyris infantile sp. n.; Kozłowski 1929: 230, pl. 11: 47.

1978 Protathyris infantile Kozłowski, 1929 ; Rubel and Teller 1978: 479, pl.3: 3, 4.

1985 Pseudoprotathyris infantilis ( Kozłowski, 1929) ; Nikiforova et al. 1985: 54, pl. 14: 11 [full synonymy herein].

1986 Pseudoprotathyris infantilis (Kozłowski) ; Grunt 1986: 51, pl. 3: 2.

2002 Pseudoprotathyris infantilis ( Kozłowski, 1929) ; Musteikis and Modzalevskaya 2002: 620, pl. 5: 1–7, fig. 16.

Material.—11 more or less complete shells and 6 fragmentary specimens. The species were found at Dnistrove in interval at 0.3–1.2 m 1.3 m above the S–D boundary (beds −5, −4, −3, −1, 1.5, and 4).

Dimension of the two figured shells (in mm; see Fig. 19G, H , respectively): length, 5.3, 5.7; width, 4.5, 5.2; thickness, 2.5, 2.6.

Remarks.—The specimens from Dnistrove found at the base of the Khudykivtsi Beds appear to be conspecific with P. infantilis as described by Kozłowski (1929: 230–231, pl. 11: 47) from the Dzvenyhorod Beds of the Skala Horizon (former Dzwinogorod Beds) and by Modzalevskaya (1979: 60–62, pl. 4: 6–8, text−fig. 11) from the Dzvenyhorod, Khudykivtsi, and Mytkiv beds. Nikiforova et al. (1985) noted that the species is most common through the Khudykivtsi Beds. They selected a neotype of the species ( Nikiforova et al. 1985: 54, pl. 14: 11) from the Dzvenyhorod Beds at the village of Dzvenyhorod. Two shells from Dnistrove are illustrated here ( Fig. 19G, H ) together with serial sections of one shell ( Fig. 17 ).

Stratigraphic and geographic range.—As noted by Nikiforova et al. (1985) P. infantilis appears in the Dzvenyhorod Beds (uppermost Silurian) and ranges through the Khudykivtsi and Mytkiv beds (lower Devonian).

Figures

Fig. 17. Transverse serial sections through shell of Pseudoprotathyris infantilis (Kozłowski, 1929). ZPAL Bp. 56/186a. Numbers refer to distance in mm from ventral umbo. Dnistrove, bed −4.

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.