Septopora flabellata Nikiforova, 1933

Ernst, Andrej, Senowbari-Daryan, Baba & Hamedani, Ali, 2006, Middle Permian Bryozoa from the Lakaftari area, northeast of Esfahan (central Iran), Geodiversitas 28 (4), pp. 543-590 : 563

Septopora flabellata Nikiforova, 1933 ( Figs 7 I-M; 8A-C; Table 18)

Septopora flabellata Nikiforova, 1933: 27 , text-fig. 8. — Morozova 1970a: 197, 198, pl. 43, figs 3, 4, text-figs 10, 11. — Gorjunova 1975: 90, 91, pl. 22, fig. 2.

LECTOTYPE (designated by Morozova 1970a). — Central Museum of Geological Prospecting , Saint Petersburg, Russia. Thin section No. 62. Transcaucasia (Nakhichevan); Gnishik Horizon , Middle Permian, Murgabian (= Wordian).

MATERIAL EXAMINED. — 1-1-(1-3), 1-3-(1-3), 1-7-(1- 4), 2-(1-3), 3-1, 4-5-4, 4-5-7, 4-6-2, 4-6-4, 4-12-4, 4-15-(6-7), 5-3-1, 5-8-3, 7-1-2, 7-3-(3-4), 7-5-(5-6), 8-1-(1-3), 9-4-2, 9-4-3, 9-4-7, 9-5-2, 9-6-2, 9-6-4, 9-7-1, 10-2-8, 11-2-2, 12-1-(7-8), 13-4-4, 19-4-4, 19-4-7, 20-1-4, 20-2-(1-6), 22-1-1, 23-6-2, 23-6-3, 23-6-9, 24-5-8, 25-1-1, 25-4-2, 25-9-2, 25-9-3, 25- 13, 26-1-2.

OCCURRENCE. — Transcaucasia (Nakhichevan), Gnishik Horizon, Middle Permian, Murgabian (= Wordian) ( Morozova 1970a). Lakaftari: central Iran, Jamal Formation, Middle Permian.

DESCRIPTION

Micrometric formula: 11-16/11-14//16-20. Slender funnel-shaped, reticulated colonies with straight branches, joined by dissepiments; up to 30 cm high. New branches appearing by development of dissepiments to new branches or by bifurcation of branches. Autozooecia arranged in two alternating rows on branches and dissepiments, open on inside of the colony. Apertures circular to slightly oval, with low and thin peristomes bearing few small nodes, usually spaced 2 per length of a fenestrule. Shape of fenestrules varying from oval, narrow oval to rectangular and V-shaped. Obverse keel high with irregularly shaped elongated and prominent nodes. Nodes long, irregularly shaped, often having stellate shape, widening in the upper part. Smaller nodes of similar shape distributed on the reverse side, often arranged in 2-3 rows. Abundant microacanthostyles on the reverse surface of the colony arranged in regular rows. Internal granular skeleton thick, well developed, continuous with obverse keel, nodes, microacanthostyles, rods, peristome and across dissepiments. Outer lamellar skeleton sometimes extremely thick, containing small hyaline rods. Cyclozooecia abundant, spaced throughout the colony, often embedded by the outer lamellar skeleton.

INTERIOR DESCRIPTION

Autozooecia rectangular in the middle tangential section, relatively high and short in longitudinal section, with well developed vestibule; elongate to branch length; aperture positioned at distal to distalabaxial end of chamber. Hemisepta absent.

COMPARISON

Septopora flabellata is similar to S. flabellatiformis Romantchuk in Morozova, 1970 ( Morozova 1970a) from the Upper Permian (Osachtin Series) of the Khabarovsk region (Russian Far East). The latter species has considerably thicker branches (0.54-0.65 vs. 0.30-0.45 mm in S. flabellata ).

Family ACANTHOCLADIIDAE Zittel, 1880

Figures

FIG. 7. — A-C, Fabifenestella jabiensis (Waagen & Pichl, 1885); A, 10-1-2, tangential section of the keel showing nodes of different sizes; B, 4-15-3, deep tangential section showing bases of autozooecial chambers with inferior hemisepta (arrow: hemisepta); C, 4- 15-2, deep oblique tangential section showing autozooecial chambers with long superior hemisepta; D-H, Fabifenestella vediensis (Morozova, 1965) n. comb.; D, 6-1, fragment of the funnel-shaped colony; E, 12-2-2, tangential section; F, 7-3-7, tangential section showing ovicells; G, 7-3-7, tangential section of the fenestrule with ovicell; H, 4-5-6, deep tangential section showing inferior hemisepta; I-M, Septopora flabellata Nikiforova, 1933; I, 20-2-5, tangential section showing carinal nods; J, 20-2-5, thin section of the reverse surface showing nods, microacanthostyles and cyclozooecia; K, 1-7-3, deep tangential section; L, 1-7-2, tangential section showing apertures, carinal nods and cyclozooecia; M, 4-12, fragment of the funnel-shaped colony. Scale bars: A, B, E, 0.25 mm; C, G, H, 0.1 mm; D, M, 10 mm; F, L, 0.5 mm, I-K, 1 mm.