Spinofenestella, Termier & Termier, 1971

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 : 186

Spinofenestella sp. 1

( Fig. 22 A-G; Appendix)

MATERIAL. — SMF 21.900- SMF 21.905.

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

EXTERIOR DESCRIPTION.

Reticulate colony formed by straight branches joined by wide dissepiments. Fenestrules oval to rectangular, long, narrow. Autozooecia arranged in two rows on branches. Autozooecial apertures circular, with low smooth peristome; 3 to 6 apertures spaced per fenestrule length. Median keel low, narrow, containing small elliptical nodes. Nodes 0.03-0.04 mm in diameter, spaced 0.38 mm from centre to centre.

INTERIOR DESCRIPTION

Autozooecia short, triangular to trapezoid in mid tangential section; with short to moderately long vestibule in longitudinal section. Axial wall between autozooecial rows strongly zigzag; aperture positioned at distal end of chamber. Superior hemisepta weakly developed; inferior hemisepta absent. External laminated skeleton well-developed on both obverse and reverse sides, traversed by small microstyles. Microstyles 0.010 -0.015 mm in diameter. Heterozooecia not observed.

COMPARISON

Spinofenestella sp. 1 most closely resembles S. ungadyjensis ( Popeko, 1967) from the Lower to Middle Carboniferous of Asiatic Russia. The branch width and fenestrule width are similar, but the fenestrules are shorter in S. ungadyjensis 1.20-1.80 mm vs 1.33-2.38 mm in the Montagne Noire material.

Figures

FIG. 22. — A-G, Spinofenestella sp. 1; A, B, tangential section, SMF 21.901; C, tangential section showing apertures and keel, SMF 21.900; D, mid-tangential section showing autozooecial chambers, SMF 21.900; E, mid-tangential section showing autozooecial chambers, SMF 21.901; F, tangential section showing autozooecial apertures, SMF 21.901; G, branch transverse section, SMF 21.901. H, Spinofenestella cf. simplaris (Trizna, 1961), tangential section, SMF 21.908. Scale bars: A, B, 1 mm; C, D, 2 mm; E, F, G, 0.2 mm; H, 2 mm.