Fistulipora monticulosa 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 : 546-548

Fistulipora monticulosa Nikiforova, 1933 ( Fig. 2A, B, D, E, G ; Table 1)

Fistulipora monticulosa Nikiforova, 1933: 10 , pl. 1, figs 9-15, text-figs 3, 4. — Morozova 1970a: 61, 62, pl. 1, fig. 2.

Fistulipora pseudomonticulosa Sakagami, 1980: 272 , pl. 31, figs 4-6.

Fistulipora sp. cf. F. monticulosa – Sakagami 1976: 400, pl. 42, figs 3, 4.

LECTOTYPE (designated by Morozova 1970a). — Central Museum of Geological Prospecting, Saint Petersburg, Russia. Thin section No. 13 ( Nikiforova 1933: pl. 1, fig. 13).Transcaucasia (Nakhichevan), River Arax; Gnishik Horizon, Middle Permian, Murgabian (= Wordian).

MATERIAL EXAMINED. — 4-3, 4-7-1, 4-12, 5-9, 5-11, 5-12, 9-5, 12x, 21-3, 23-8, 25-3.

OCCURRENCE. — Transcaucasia (Nakhichevan), Gnishik Horizon, Middle Permian, Murgabian (= Wordian). Sainbeyli: Central Turkey, Middle Permian. Abadeh: central Iran; Upper Permian ( Araxopora araxensis -Horizon). Lakaftari: central Iran, Jamal Formation, Middle Permian.

DESCRIPTION

Encrusting colonies, often hollow, tubular (encrusting ephemeral cylindrical substrates). Encrusting sheets 0.6-2.2 mm thick, tubular colonies having rounded lumen 3-6 mm in diameter. Autozooecia budding from substrate at low angles. Autozooecial apertures rounded, having well developed, horseshoeshaped lunaria, spaced 3.5-4.5 in 2 mm. Autozooecial diaphragms rare to absent in short autozooecia (often developed at their bases), abundant in longer autozooecia, complete, thin, deflected orally. Vesicles polygonal in tangential section, arranged in 1-3 rows between autozooecia, having flat or slightly concave roofs, spaced 8-15 per 1 mm of the colony thickness. Maculae consisting of vesicular skeleton, rounded, 0.66-1.20 mm in diameter, spaced regularly on the colony surface.

COMPARISON

Sakagami (1980) described a new species Fistulipora pseudomonticulosa because of rare diaphragms in autozooecia. However, an investigation of a large amount of thin sections of the present material revealed a variation in the number of autozooecial diaphragms. Fistulipora monticulosa is similar to F. timorensis , which is widely distributed in Permian rocks of Asia ( Indonesia, Thailand, Primorye, Iran). The most striking difference is the growth form: unilaminar encrusting, commonly tubular in F. monticulosa , multilamellar encrustings rare; usually uni- and multilamellar encrusting colonies in F. timorensis , tubular colonies unknown. Furthermore, apertures in F. timorensis are larger (0.35 vs. 0.29 mm in F. monticulosa ).

Figures

FIG. 2. — A, B, D, E, G, Fistulipora monticulosa Nikiforova, 1933; A, 5, cylindrical colony; B, 5-9-3, tangential section; D, 5-11-1, thin section through cylindrical colony; E, 5-9-3, longitudinal section of encrusting colony;G, 5-11-1, tangential section;C, J, L, Fistulipora sp.; C, 4-16-5, longitudinal section of encrusting colony; J, 4-16-3, tangential section; L, 4-16-3, tangential section; F, H, K, M, Fistulipora timorensis Bassler, 1929; F, 10-2-2, longitudinal section; H, K, 25-10-3, tangential section; M, 7-3-2, deep tangential section of macula center; I, N, Fistuliporidae indet. (?Eridopora); I, 4-8-11, longitudinal section; N, 19-4-2, tangential section. Scale bars: A, 10 mm; B, E, 1 mm; C, G-I, K-N, 0.5 mm; D, 3 mm; F, 0.05 mm; J, 0.2 mm.