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 : 182

Genus Spinofenestella Termier & Termier, 1971

Alternifenestella Termier & Termier, 1971: 42 .

TYPE SPECIES. — Fenestella spinosa Condra, 1902 by original designation. Lower Permian (Wolfcampian) ; North America .

DIAGNOSIS. — Reticulate colonies with relatively wide and thick branches and relatively thin dissepiments. Autozooecia arranged in two rows on the branches. Autozooecia triangular in mid tangential section, triangular to pentagonal proximal to bifurcations. Narrow keel with single row of nodes developed.

OCCURRENCE. — Lower Devonian – Upper Permian.

COMPARISON

Spinofenestella Termier &Termier, 1971 differs from the genus Rectifenestella Morozova, 1974 by the triangular shape of the autozooecia in mid tangential section.

Spinofenestella major ( Nikiforova, 1933) comb. nov. ( Fig. 21 E-I; Appendix)

Fenestella major Nikiforova, 1933: 16 . — Schulga-Nesterenko 1951: 93, 94, pl. 17, fig. 3, pl. 18, fig. 2.

Fenestella donaica – Nikiforova 1927: 250, pl. 12, figs 8, 9.

Fenestella donaica var. major Nikiforova, 1933: 16 , pl. 16, figs 4, 5. — Nekhoroshev 1948: 28, pl. 2, fig. 3, pl. 10, fig. 5.

Alternifenestella major – Gorjunova 2013: 576, 577, pl. 5, fig. 2.

MATERIAL. — SMF 21.899.

OCCURRENCE. — Carboniferous, Mississippian (upper Visean); Roque Redonde (Montagne Noire, southern France). Carboniferous, Mississippian; Ukraine, Donetz Basin. Carboniferous, Mississippian (Serpukhovian); Russian Platform. Middle Carboniferous; Kazakhstan.

EXTERIOR DESCRIPTION

Reticulate colony formed by straight branches joined by narrow dissepiments. Fenestrules oval to rectangular, about twice as long as wide. Autozooecia arranged in two rows on branches. Autozooecial apertures circular, with low smooth peristome; 3 to 5 apertures spaced per fenestrule length. Median keel low, narrow, containing small elliptical nodes. Nodes 0.03-0.05 mm in diameter, spaced 0.14-0.18 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 present, long, curved proximally; inferior hemisepta absent. External laminated skeleton well-developed on both obverse and reverse sides. Heterozooecia not observed.

COMPARISON

Spinofenestella major ( Nikiforova, 1933) comb. nov. differs from Spinofenestella donaica ( Lebedev, 1924) in longer fenestrules (0.77-1.02 mm vs 0.55-0.65 mm in S. donaica ). Spinofenestella major comb. nov. differs from S. donaiciformis (Schulga-Nesterenko, 1951) in smaller and more closely spaced nodes on the median keel (distance between node centres 0.14-0.18 mm vs 0.30-0.42 mm in S. donaiciformis ).

Spinofenestella cf. simplaris ( Trizna, 1961) ( Figs 22H ; 23 A-C; Appendix)

Fenestella simplaris Trizna, 1961: 75 , 76, pl. 8, figs 3, 4, text-fig. 27.

MATERIAL. — SMF 21.906- SMF 21.910.

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 4 apertures spaced per fenestrule length. Large elliptical nodes on the low keel, widely and irregularly spaced.

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. Heterozooecia not observed.

COMPARISON

The present material is similar to Spinofenestella simplaris ( Trizna, 1961) from the Mississippian of Urals. However, the present material has significantly longer fenestrules (0.83-1.02 mm vs 0.55-0.75 mm in S. simplaris ). The present material differs from Spinofenestella plebeia ( M’Coy, 1844) from the Lower Carboniferous of Ireland, in wider branches (average branch width 0.38 mm vs 0.29 mm in S. plebeia ), and wider dissepiments (average dissepiment width 0.23 mm vs 0.17 mm in S. plebeia ). It differs from S. triangularis ( Nekhoroshev, 1953) from the Mississippian of Kazakhstan in wider branches (branch width 0.35-0.42 mm vs 0.15-0.20 mm in S. triangularis ).

Figures

FIG. 21. — A, Megacanthopora enodata n. sp., longitudinal section showing autozooecial walls with aktinotostyles and mural spines, paratype SMF 21.895. B-D, Rectifenestella sp., SMF 21.898, tangential section; E-I, Spinofenestella major (Nikiforova, 1933) comb. nov., SMF 21.899; E-G, tangential section of the colony; H, mid-tangential section of the branch showing autozooecial chambers with hemisepta; I, tangential section of the branch showing autozooecial apertures. Scale bars: A, C, G, 1 mm; B, E, 2 mm, D, H, I, 0.2 mm; F, 0.5 mm.

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.

FIG. 23. — A-C, Spinofenestella cf. simplaris (Trizna, 1961); A-B, mid-tangential section, SMF 21.908; C, tangential section showing nodes on keel (arrow), SMF 21.906; D-I, Spinofenestella sp. 2, SMF 21.911; D-G, tangential section; H, mid-tangential section showing autozooecial chambers; I, autozooecial aperture. Scalr bars: A, E-G,, 1 mm; B, H, 0.2 mm; C, 0.5 mm; D, 2 mm; I, 0.1 mm.