Septopora blanda Moore, 1929

Ernst, Andrej, Claussen, Anna Lene, Seuss, Barbara & Wyse Jackson, Patrick N., 2022, Stenolaemate bryozoans from the Graham Formation, Pennsylvanian (Virgilian) at Lost Creek Lake, Texas, USA, Palaeontologia Electronica (a 15) 25 (2), pp. 1-56 : 32

Septopora blanda Moore, 1929

Figures 17 F-I, 18A-C; Appendix

1929 Septopora blanda Moore , p. 130, pl. 16, figs. 6, 12, pl. 17, fig. 2.

1930 Septopora blanda Moore, 1929 ; Warthin, p. 39, pl. 3, figs. 8a–b.

2016 Septopora blanda Moore, 1929 ; Ernst et al., p. 532-534, figs. 7b-d, 9g.

Material. SNSB-BSPG 2020 XCI 47, SNSB-BSPG 2020 XCI 54, SNSB-BSPG 2020 XCI 119, SNSB-BSPG 2020 XCI 120.

Exterior description. Reticulate colonies formed by straight or slightly undulating branches fused by pinnae. Fenestrules oval to reversed V-shaped. Autozooecia arranged in two rows on branches. Four to five apertures spaced per fenestrule length. Autozooecial apertures circular to oval. Elliptical nodes regularly arranged in a single row on the low keel between apertures, 0.08–0.10 mm wide and spaced 0.55–0.63 mm from centre-to-centre.

Interior description. Autozooecial chambers tetragonal, parallelogram-shaped in the mid-tangential section. Hemisepta absent. Extrazooidal skeleton well-developed. Cyclozooecia common, spaced irregularly on obverse surface, 0.05–0.08 mm in diameter.

Remarks. Septopora blanda Moore, 1929 , differs from S. interporata Rogers, 1900 , from the Pennsylvanian of Kansas, in having wider spaced nodes on keel (distance between node centres 0.55–0.63 mm vs. 0.3–0.4 mm in S. interporata ).

Occurrence. Wewoka Formation, middle Pennsylvanian (upper Desmoinesian); Oklahoma, USA. Deese Group, Boggy Formation, Pennsylvanian (Missourian); Oklahoma, USA. Upper Graham Formation, Pennsylvanian (Virgilian); Texas, USA. Graham Formation, Pennsylvanian (Virgilian); TXV-200 (“Spillway section at Lost Creek Lake”), Texas, USA.

Figures

FIGURE 17. Polypora aff. hexagona Moore, 1929 (A–E): tangential section showing autozooecial apertures and chambers, nodes, microstyles, and reproductive heterozooecia (arrows) (XCI 55). Septopora blanda Moore, 1929 (F– I): F – tangential section showing autozooecial chambers and cyclozooecia (XCI 54); G – colony fragment with cyclozooecia on the reverse side (arrows) (XCI 119). H, I – colony fragment with autozooecial apertures, keel nodes, and cyclozooecia (arrows) (XCI 120).