Fabifenestella Morozova, 1974

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 : 560-562

Genus Fabifenestella Morozova, 1974

TYPE SPECIES. — Fenestella praevirgosa Shulga-Nesterenko, 1951 . Upper Carboniferous, Russian Platform.

Fabifenestella jabiensis ( Waagen & Pichl, 1885) ( Figs 6O, P ; 7 A-C; Table 16)

Fenestella jabiensis Waagen & Pichl, 1885: 778-780 , pl. 87, fig. 4, pl. 88, figs 1, 2. — Sakagami 1970?: 54, 55, pl. 9, figs 4, 5.

Fabifenestella jabiensis – Morozova 2001: 53.

MATERIAL EXAMINED. — 4-4-1, 4-15, 4-16, 4-18, 5-2, 5-8-4, 7-3-1, 7-6, 10-1, 10-2(a), 25-5, 25-8, 25-10, 25-11, 25-12.

OCCURRENCE. — Salt Range: Pakistan, Middle Permian (Guadalupian) ( Waagen & Pichl 1885). Lakaftari: central Iran, Jamal Formation, Middle Permian. Peninsular Thailand, Lower Permian (Artinskian) ( Sakagami 1970).

DESCRIPTION

Micrometric formula: 13-19/7-12//17-21. Reticulated colonies with straight branches, joined by relatively thick dissepiments. Bifurcation common. Autozooecia arranged in 2 alternating rows on branches. Apertures circular, with 8 peristomal nodes, spaced 3-4 per length of a fenestrule. Shape of fenestrules varying from oval to slightly rectangular. Keel low, carrying two alternating rows of small nodes. Some colonies containing larger nodes between smaller ones. Internal granular skeleton thin, continuous with obverse keel, nodes, rods, peristome and across dissepiments. Outer lamellar skeleton moderately thick, containing abundant microacanthostyles 5-15 µm in diameter, with distinct hyaline cores and very thin dark laminated cores. No heterozooecia observed.

INTERIOR DESCRIPTION

Autozooecia rectangular to bean-shaped in the middle tangential section, low and elongated, with well developed vestibule; aperture positioned at distal to distal-abaxial end of chamber. Superior hemisepta long; inferior hemisepta long, low, separating the proximal third of the chamber.

COMPARISON

Fabifenestella jabiensis differs from F. vediensis n. comb. in having thicker branches, and larger fenestrules. Sakagami (1970) described a specimen from Artinskian of Peninsular Thailand, which he placed in Fabifenestella jabiensis . However, it has much thicker branches (0.52-0.60 vs. 0.30-0.48 mm in present material), although revealing close morphological similarity to the material described in present paper. Waagen & Pichl (1885) did not give any detailed measurements for F. jabiensis as well as no scale for the plates. Unfortunately, the deposition of the type material for this species is also unknown.

REMARK

Morozova (2001) mentioned two species under different generic names: Minilya jabiensis and Fabifenestella jabiensis . They correspond to the same species, Fabifenestella jabiensis .

Figures

FIG. 6. — A-E, Spinofenestella sp. 1; A, B, 17-1-1, tangential section; C, 23-3-1, tangential section showing apertures with apertural nodes; D, 9-5-7, cross section showing the autozooecial chamber with terminal diaphragm (arrow: terminal diaphragm); E, 9-5-10, cross section showing the autozooecial chamber and extensive depositions of outer laminated skeleton; F-I, Spinofenestella sp. 2; F, 9-7, tangential section showing the autozooecial apertures with septa and nodes; G, 9-5-8, tangential section showing the autozooecial apertures and carinal nodes; H, 9-7, tangential section showing the autozooecial apertures with septa and nodes; I, 7-3-5, tangential section; J-L, Alternifenestella sayensis Termier & Termier, 1971; J, 13-4-1, tangential section showing the autozooecial apertures and carinal nodes; K, 5-8-1, tangential section showing the autozooecial apertures and autozooecial chambers; L, 13-4-1, tangential section; M, N, Minilya perelegans (Waagen & Pichl, 1885); M, 25-3-5, tangential section; N, 4-7-3, tangential section; O, P, Fabifenestella jabiensis (Waagen & Pichl, 1885), 25-10-5, tangential section. Scale bars: A, 1 mm; B, I-N, P, 0.5 mm; C, 0.2 mm; D, F, H, 0.1 mm; E, G, O, 0.25 mm.

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.