Streblotrypa (Streblotrypa) multipora Warthin, 1930

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 : 15-16

Streblotrypa (Streblotrypa) multipora Warthin, 1930

Figure 8 D-G; Appendix

1930 Streblotrypa multipora Warthin , p. 42, pl. 3, fig. 15.

Material. SNSB-BSPG 2020 XCI 39b, SNSB-BSPG 2020 XCI 40, SNSB-BSPG 2020 XCI 41, SNSB-BSPG 2020 XCI 43, SNSB-BSPG 2020 XCI 104.

Description. Ramose colonies, branches 0.43– 0.76 mm in diameter, with 0.19–0.38 mm wide endozones and 0.10–0.20 mm wide exozones. Branch transverse sections rounded to oval. Autozooecia budding from the axial bundle in a regular spiral pattern at angles of 18–28°, bending in exozones and intersecting colony surface at angles of 60–80°, having long inflated proximal parts, rounded-polygonal in transverse section in the endozone. Axial bundle indistinct, formed by 2–5 axial zooecia, 0.11–0.15 mm in diameter. Autozooecial apertures oval, opening around the branches in regular diagonal rows. Autozooecial boundaries marked by sharp ridges on the colony surface, which form a roughly hexagonal pattern. Superior hemisepta absent; inferior hemisepta well-developed, thin, placed approximately in the middle of the chamber, curved proximally. Autozooecial diaphragms rarely occurring. Metazooecia oval to rounded, usually 7–10 arranged in 2–3 rows between apertures, but often clustered in parts of branches lacking apertures. Autozooecial walls hyaline, 0.010 –0.015 mm thick in endozone; laminated in exozone.

Remarks. Streblotrypa (Streblotrypa) multipora Warthin, 1930 , differs from S. (S.) merceri Morningstar, 1922 , from the Pennsylvanian of Ohio by presence of 7–10 metazooecia between autozooecial apertures instead of four in the latter species. Streblotrypa (Streblotrypa) multipora differs from S. (S.) heltzelae Ernst et al., 2016 , from the Boggy Formation of Oklahoma by its absence of acanthostyles.

Occurrence. Upper Wetumka – lower Wewoka Formation, Pennsylvanian (Desmoinesian), Oklahoma, USA. Graham Formation, Pennsylvanian (Virgilian); TXV-200 (“Spillway section at Lost Creek Lake”), Texas, USA.

Figures

FIGURE 8. Rhombopora lepidodendroides Meek, 1872 (A–C): A – branch transverse section (XCI 58a); B, C – branch longitudinal section showing autozooecial chambers and aktinotostyles in autozooecial wall (XCI 45b). Streblotrypa (Streblotrypa) multipora Warthin, 1930 (D–G): D, E – branch fragment showing autozooecial apertures and metazooecia (XCI 104); F – branch transverse section showing autozooecial chambers and axial bundle (XCI 39b); G – branch longitudinal section showing branch transverse section showing autozooecial chambers with hemisepta (arrows) and axial bundle (XCI 40). Rhombocladia delicata Rogers, 1900 (XCI 105) (H–I) – branch fragment (H) and colony surface showing autozooecial apertures, acanthostyles and paurostyles (I).