Polypora principalis Gorjunova, 1975

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 : 572

Polypora principalis Gorjunova, 1975 ( Fig. 11 E-G; Table 28)

Polypora principalis Gorjunova, 1975: 97 , pl. 26, fig. 3. — Gorjunova & Morozova 1979: 87, pl. 26, fig. 2.

HOLOTYPE. — No. 2351/392, PIN; Central Pamir ( Tajikistan); Lower Permian.

MATERIAL EXAMINED. — 4-3.

OCCURRENCE. — Central Pamir ( Tajikistan), Lower Permian ( Gorjunova 1975). Central Mongolia, Permian ( Gorjunova & Morozova 1979). Lakaftari: central Iran, Jamal Formation, Middle Permian.

DESCRIPTION

Micrometric formula: 6/4-5//15. Single fragment of reticulated colony with straight branches, joined by relatively thin dissepiments. Bifurcation common. Autozooecia arranged in 3-5 alternating rows on branches, becoming 7 at the site of bifurcation and 3 after the bifurcation. Apertures circular, spaced 6-7 per length of a fenestrule; rarely 1-2 small nodes developed in peristome. Shape of fenestrules varying from oval to rectangular. Keels absent. Nodes small, arranged in regular rows between apertures on the obverse colony surface, widely spaced, hyaline. Internal granular skeleton moderately thick, well developed, continuous with nodes, rods, peristome and across dissepiments. Outer lamellar skeleton moderately thick, containing abundant rods 5- 6 µm in diameter.

INTERIOR DESCRIPTION

Autozooecia rhombic to hexagonal in the middle tangential section, irregularly shaped in place of bifurcation; high and short in longitudinal section, with well developed vestibule; elongate to branch length; aperture positioned at distal to distal-abaxial end of chamber. Hemisepta absent.

COMPARISON

The investigated material shows close similarity to Polypora principalis from the Lower Permian of Central Pamir. Polypora nianekensis Morozova, 1981 from the Upper Permian of the Northeast of Russia is also similar. The latter species has thicker branches (1.00-1.20 vs. 0.75-0.90 mm in P. principalis ).

Figures

FIG. 11. — A-D, Polypora sinokoninckiana Yang & Lu, 1962; A, 1-3-4, tangential section, showing apertures with nodes and nodes on colony surface; B, 9-5-4, tangential section of the branch; C, 9-5-4, deep tangential section of the branch; D, 9-5-4, cross section of the branch; E-G, Polypora principalis Gorjunova, 1975; E, 4-3, tangential section; F, 4-3, deep tangential section of the branch; G, 4-3, tangential section showing autozooecial apertures; H, I, Polyporella sp., 4-12, tangential section; J, K, Q, Fenestrida indet.; J, Q, 10-1-2, tangential section; K, 10-1-2, deep tangential section; L-P, Lakkela jamalica n. gen., n. sp.; L, SMF 2115, holotype, tangential section;M, SMF 2115,holotype,tangential section showing apertures and acanthostyles;N, 1-8-2, paratype,deep tangential section; O, 9-5-9, tangential section showing apertures and heterozooecia; P, SMF 2115, holotype, longitudinal section. Scale bars: A, G, M, O, 0.2 mm; B, C, F, I, L, 0.5 mm; D, J, K, N, P, 0.25 mm; E, H, 2 mm; Q, 1 mm.