Mackinneyella dzhulfensis ( Morozova, 1965 )

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 : 566

Mackinneyella dzhulfensis ( Morozova, 1965) ( Figs 8L, M ; 9 A-C, E; Table 21)

Polypora dzhulfensis Morozova, 1965: 193 , pl. 28, fig. 1; 1970a: 216, pl. 50, fig. 1, pl. 53, fig. 3.

Mackinneyella dzhulfensis – Morozova & Lisitsyn 1996: 45.

HOLOTYPE. — No. 1613/31, PIN; Transcaucasia (Nakhichevan); Gnishik Horizon, Middle Permian, Murgabian (= Wordian).

MATERIAL EXAMINED. — 5-7-5, 12-2-3, 13a-b.

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

DESCRIPTION

Micrometric formula:7-8.5/5-7//13-16. Reticulated colonies with straight branches, joined by dissepiments. Bifurcation common. Autozooecia arranged in 5-6 alternating rows on branches, becoming 7-8 in the place of bifurcation. Apertures circular, arranged in regular alternating rows, spaced 4-5 per length of a fenestrule. Shape of fenestrules varying from oval to rectangular. Keels absent. Nodes small, regularly spaced on the obverse colony surface; usually 3-4 surrounding each aperture. Internal granular skeleton thick, well developed, continuous with rods, nodes, peristome and across dissepiments. Outer lamellar skeleton moderately thick, containing abundant rods 5-10 µm in diameter. Rods arranged in distinct longitudinal rows on the reverse side.

INTERIOR DESCRIPTION

Autozooecia rhombic to irregular hexagonal in the middle tangential section, irregularly shaped in the 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

Mackinneyella dzhulfensis differs from M. robustiformis from the Middle Permian (Gnishik Horizon, Guadalupian) of Transcaucasia, in having smaller fenestrules, and different microstructure of the reverse side (regular rows of rods instead of microacanthostyles).

Figures

FIG. 8. — A-C, Septopora flabellata Nikiforova,1933;A, 1-7-4, longitudinal section showing autozooecial chambers and cyclozooecia; B, 20-5-4,longitudinal section showing autozooecial chambers,cyclozooecia and the outer laminated skeleton with microacanthostyles; C, 1-3-1, cross section showing autozooecial chambers and cyclozooecia; D-F, Penniretepora afghanica n. sp.; D, paratype 14, free colony;E, 10-2-11, tangential section;F, holotype SMF 2114,tangential section; G-K, Mackinneyella praepluriformis (Morozova,1965); G, 24-5-2, deep tangential section showing autozooecial chambers; H, 24-5-2, tangential section showing autozooecial apertures, nodes and hyaline rods; I, 25-12-1, tangential section; J, 16-1, fragment of the colony; K, 16-1-4, cross section of the branch; L, M, Mackinneyella dzhulfensis (Morozova, 1965); L, 13b, cross section of the branch; M, 13, fragment of the colony. Scale bas: A-C, G, K, L, 0.5 mm; D, 2 mm; E, 1 mm; F, 0.25 mm; H, 0.1 mm; I, J, M, 10 mm.

FIG. 9. — A-C, E, Mackinneyella dzhulfensis (Morozova,1965);A, 13a, deep tangential section;B, 12-2-3,tangential section; C, 12-2-3, deep tangential section; E, 12-2-3, tangential section showing apertures and nodes; D, F-K, Mackinneyella robustiformis (Morozova, 1965); D, 4-18-2, deep tangential section; F, 4-18-2, tangential section showing apertures with apertural nodes; G, 4-18-2, tangential section of the branch; H, 4-18-2, deep tangential section showing autozooecial chambers; I, 19-4-10, cross section of the branch; J, 4-18-2, thin section showing reverse surface with microacanthostyles and hyaline rods; K, 19-4-10, cross section of the branch showing outer laminated skeleton with microacanthostyles; L-R, Polypora soyanensis Morozova, 1970; L, 23-6-3, tangential section; M, 18-1-6, tangential section; N, 1-8-2, tangential section; O, 18-1-6, cross section; P, 18-1-6, tangential section showing ovicell; Q, 23-6-3, tangential section showing radial structure of a node; R, 23-6-3, tangential section showing apertures and nodes. Scale bars: A, L, M, 1 mm; B, D, 2 mm; C, E, G-I, O, 0.25 mm; F, 0.2 mm; J, K, P-R, 0.1 mm; N, 0.5 mm.