Eridopora beilensis Perkins and Perry

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 : 6-9

Eridopora beilensis Perkins and Perry in Perkins et al., 1962

Figures 4 D-F, 5A-B; Appendix

1962 Eridopora beilensis Perkins and Perry in Perkins et al., p. 12, pl. 3, figs. 1-4.

Material. SNSB-BSPG 2020 XCI 36, SNSB-BSPG 2020 XCI 59a, b, SNSB-BSPG 2020 XCI 98.

Description. Encrusting colonies, 0.20–1.26 mm thick. Autozooecia growing from thin epitheca, bending in the early exozone to the colony surface. Basal diaphragms rare to absent. Autozooecial apertures circular to oval. Lunaria well-developed, triangular; ends of lunaria not indenting autozooecia. Vesicles small to large, separating autozooecia in 1–2 rows, 13–16 surrounding each autozooecia aperture, with rounded roofs, polygonal in tangential section. Autozooecial walls granular prismatic, 0.015 –0.023 mm thick. Maculae not observed.

Remarks. The species Eridopora cf. beilensis Perkins and Perry, 1962 , from the Arnsbergian (= Serpukhovian; late Mississippian) of Northern Yorkshire, England, described by Bancroft (1984) in his unpublished PhD dissertation is very similar to the original description of this species and the present species. However, the present species has smaller autozooecial apertures (average aperture width 0.30 mm vs. 0.39 mm in Eridopora cf. beilensis in Bancroft’s PhD). Eridopora beilensis differs from E. macrostoma Ulrich, 1882 , in having smaller autozooecial apertures (average aperture width 0.30 mm vs. 0.39 mm in E. macrostoma ).

Occurrence. Lecompton Limestone, Pennsylvanian (Virgilian); Kansas, USA. Graham Formation, Pennsylvanian (Virgilian); TXV-200 (“Spillway section at Lost Creek Lake”), Texas, USA.

Figures

FIGURE 4. Fistulipora nodulifera Meek, 1872 (A–C): A – colony surface with autozooecial apertures and lunaria (XCI 97); B – tangential thin section showing autozooecial apertures with lunaria and vesicles (XCI 29); C – longitudinal thin section showing autozooecial chambers and vesicles (XCI 56b). Eridopora beilensis Perkins and Perry in Perkins et al., 1962 (D–F): discoidal colony showing autozooecial apertures with triangular lunaria (XCI 98).