Septatrypa (Septatrypa) secreta, Kozlowski, 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 : 918-919

Sepatrypa (Septatrypa) secreta Kozłowski, 1929

Figs. 15A, B , 16 .

1929 Septatrypa secreta sp. n.; Kozłowski 1929: 177, pl. 9:18–24; fig. 58.

1985 Septatrypa secreta Kozłowski, 1929 ; Nikiforova et al. 1985: 44–45, pl. 11: 9–11; fig. 6 [full synonymy herein].

2004 Septatrypa secreta Kozłowski, 1929 ; Copper 2004: 126–127, figs. 86, 87.

Material.—122 complete and well preserved shells and 140 fragmentary specimens. In the studied section it appears at 5.5 m above the S–D boundary (beds 47–48) where it is the most numerous species, comprising 27% of the brachiopod assemblage. In addition, five specimens were recovered from loose blocks from the uppermost part of the section.

Remarks.—This is one of the most common brachiopod species in the studied section at Dnistrove. The studied material is clearly conspecific with S. secreta as described and illustrated in great detail by Kozłowski (1929: 177–179, fig. 58, pl. 9: 18–24), Nikiforova (1954: 128–129, pl. 14: 8–9), Nikiforova et al. (1985: 44–45, fig. 6, pl. 11: 9–11), Biernat and Godefroid (1992: 44–48, pl. 1: 57–67, figs. 1, 2) and Copper (2004: 126–127, figs. 86, 87) from Podolia. Statistical characteristics of the studied material from Dnistrove are given on Fig. 16 .

Stratigraphic and geographic range.—According to Nikiforova et al. (1985) the species is confined to the lower part of the Borshchiv Horizon (Khudykivtsi Beds; former Tajna Beds).

Figures

Fig. 15. Atrypide brachiopods from the Silurian–Devonian boundary beds at Dnistrove (Podolia, Ukraine). A, B. Sepatrypa (Septatrypa) secreta Kozłowski, 1929. Two shells ZPAL Bp. 56/74 (A) and ZPAL Bp. 56/75 (B) in dorsal (A1, B1), ventral (A2, B2), lateral (A3, B3), posterior (A4, B4), and anterior (A5, B5) views. C. Lissatrypa leprosa Kozłowski, 1929; shell ZPAL Bp. 56/100a in dorsal (C1), ventral (C2), lateral (C3), posterior (C4), and anterior (C5) views. Beds 47–48 (A, B) and loose block between the trench and well (C). Scale bars 1 mm.

Fig. 16. Scatter diagrams of shell width (A) and shell thickness (B) to shell length ratios in Sepatrypa (Septatrypa) secreta Kozłowski, 1929. Dnistrove, beds 47–48.