Sulcoretepora d’Orbigny, 1849

Ernst, Andrej, Wyse Jackson, Patrick N. & Aretz, Markus, 2015, Bryozoan fauna from the Mississippian (Visean) of Roque Redonde (Montagne Noire, southern France), Geodiversitas 37 (2), pp. 151-213 : 168

Genus Sulcoretepora d’Orbigny, 1849

Arcanopora Vine, 1884: 204 .

Acanthopora Vine – Morozova 1960: 86 (incorrect subsequent spelling). — Mstania Schulga-Nesterenko 1955: 175.

TYPE SPECIES. — Flustra ? parallela Phillips, 1836 by original designation. Lower Carboniferous of Whitewell; Yorkshire, England.

DIAGNOSIS. — Colony narrow bifoliate ribbons, dichotomously branched in plane of mesotheca; elongate, rounded autozooecia in ranges, rhombically arranged on lateral sides of branches; lunaria elevated on proximolateral sides of autozooecia; range walls elevated; monticules absent; branch margins narrow, noncelluferous. Mesotheca with dark central layer and laminated outer layers; sharply folded in centre, undulatory near branch margins; median tubules absent. Autozooecia full width and rectangular to parallelogram shaped in deep tangential section; contiguous; alternating across mesotheca. Compound range walls with dark median zone continuous into boundary zone in mesotheca; lateral zones laminated; branched dark zones and tubuli in thickened range walls in exozone. Autozooecia subquadrate to subhemispherical in cross section at mesotheca; angular teardrop shaped in deep tangential section in mid exozone and partially isolated between range walls by small, blisterlike vesicles. Lunaria laminated, indistinct. Vesicles adjacent to mesotheca only at noncelluliferous margins. Stereom laminated with tubules in endozone.

OCCURRENCE. — Devonian to Permian, Europe, North America, Asia.

COMPARISON

Sulcoretepora d’Orbigny, 1849 differs from Cystodictya Ulrich, 1882 by absence of hemisepta, often plicated and folded mesotheca as well as by distinctly tripartite wall microstructure.

Sulcoretepora parallela ( Phillips, 1836) ( Fig. 14 A-E; Appendix)

For synonymy see Wyse Jackson (1996: 158).

MATERIAL. — SMF 21.824- SMF 21.837, TCD.60342.

OCCURRENCE. — Carboniferous, Mississippian (Visean); Roque Redonde (Montagne Noire, southern France), Britain, Ireland.

DESCRIPTION

Branched bifoliate colonies.Branches lens-shaped in transverse section, 0.60-1.08 mm wide and 0.54-0.75 mm thick in the thickest portion of transverse section. Autozooecia short, budding from a straight mesotheca, trapezoid to semicircular in transverse section at their bases, rectangular in deep tangential section, becoming rounded in the exozone. Mesotheca 0.005 - 0.010 mm thick, protruding laterally on both sides of colony. Rare planar diaphragms present in autozooecia. Autozooecial apertures circular to oval, arranged in 3-5 alternating rows on the colony surface. Lunaria obscure. Vesicles few, flat, having rounded roofs,occurring mainly at the base of exozone.Stereom weakly developed, laminated, containing small tubules.Longitudinal crests dividing apertural rows well developed.

COMPARISON

Sulcoretepora parallela ( Phillips, 1836) is similar to S. magnistriata Schulga-Nesterenko,1955 from the Lower Carboniferous of Russia but differs in smaller branch width and thickness, as well as in smaller autozooecial apertures (autozooecial aperture width 0.08-0.13 mm vs 0.10-0.15 mm in S. magnistriata ).

Figures

FIG. 14. — A-E, Sulcoretepora parallela (Phillips, 1836); A, deep tangential section, SMF 21.824. B, tangential section, SMF 21.824; C, tangential section, SMF 21.837; D, longitudinal section,SMF 21.827. E, branch transverse section, SMF 21.833; F-H, Ramiporalia robusta Delvolve & McKinney, 1983, branch transverse section, SMF 21.843. Scale bars: A, B, D, G, 0.5 mm; C, E, H, 0.2 mm; F, 1 mm.