FAMILY SELETONELLACEAE

TRIBE ACICULELLEAE

GENUS Aciculella PIA 1930, non in HIRMER 1927

SPECIES Aciculella preromangica (PRATURLON 1963) OTT 1974

(by Anonymous)

1. Synonymy list

1963 Macroporella preromangica n. sp.- Praturlon, Pl. III, fig. 1-8

1967 Macroporella preromangica.- Accordi & Broglio Loriga, Pl. XV, fig. 2, from Praturlon (1963: Pl. III, fig. 3)

1971 Aciculella ogilvie-gordonae n. sp.- Elliott, Pl. 118, fig. 1; Pl. 119, fig. 1-2 & 5

1974 Aciculella preromangica n. comb.- Ott, p. 45, not illustrated

1986 (?)  Aciculella ogilvie-gordone [sic].- Mirković, Pl. XII, fig. 4

1987 Macroporella preromangica.- Noé, Pl. 29, fig. 4

1988 Macroporella preromangica.- Broglio Loriga et alii, Pl. 3, fig. 2

1988 Aciculella ogilvie-gordonae.- Deloffre, Pl. 4, fig. 15, from Elliott (1971: Pl. 119, fig. 1)

2. Types

holotype of Aciculella preromangica: Pl. III, fig. 3, thin section N° F53, A. Praturlon Collection, Micropalaeontological Collection, Institute of Geology and Palaeontology, Roma (Italy)

holotype of Aciculella ogilvie-gordonae: Pl. 118, fig. 1, thin section N° V.53904, G.F. Elliott Collection, British Museum (Natural History), London (United-Kingdom)

paratypes of Aciculella ogilvie-gordonae: Pl. 119, fig. 1, thin section N° V.53903; Pl. 119, fig. 5, thin section N° V.53905, G.F. Elliott Collection, British Museum (Natural History), London (United-Kingdom)

type locality of Aciculella preromangica: Preromang, Val Badia/Gadertal, Trentino-Alto Adige (Italy)

type locality of Aciculella ogilvie-gordonae: Plesch d'Inaz, Val Gardena/Grödnertal, Trentino-Alto Adige (Italy)

stratum typicum of Aciculella preromangica: Upper Permian (Bellerophon Fm, uppermost part of the "Bellerophon-zone")

stratum typicum of Aciculella ogilvie-gordonae: Upper Permian (Bellerophon Limestone)

3. Diagnosis

(none)

4. Description

original description of Aciculella preromangica (Praturlon, 1963): « Aspect in thin section – Well calcified specimens. Central hollow often recognizable only by different calcite colour, without any well-traced limit, and rarely bituminized. Branches on the contrary always filled with secondary dark detritus. Rare axial sections show cylindrical, without any annulation, thallus. The branches, well developed but few, are easily recognizable in frequent oblique sections where they seem sometimes to be closed.

Central hollow and calcareous wall – Cylindrical thallus (Pl. III, 2,3). Central hollow not very large, usually a third of outer diameter. The calcification, total in fossils, affected wholly the branches but not the sell-membrane ( in fact no well-traced limit is recognizable between calcareous wall and central hollow). The main cell, in comparison with the branches, appears reduced in size; that is an usual thing in the genus Macroporella, in which the branches would be assimilatory are reproductive organs.

Pores shape and arrangement – Few (15-22 in cross sections, usually 16-18), long, somewhat large in diameter, simple, primary, aspondy1 branches start from central hollow either perpendicular to the stem or slightly ascending. They open to the exterior and sometimes in periphery are in mutual contact, causing a polygonal pattern to appear on the surface (Pl. 111, 6); sometimes, on the contrary, at the periphery they are still spaced: in this case tangential sections show (Pl. III, 3) round pores. Our opinion is that this difference is in connection either with the age of the thalli or with different parts of a single thallus.

The real shape of the branches, which in oblique sections often appear closed, is recognisable in the rare axial sections and at the borders of oblique sections (Pl. III, 3, 5, 6). They quickly expand in proximal portion, being then almost cylindrical going to the exterior, scarcely increasing in diameter. So also the slightly oblique sections show egg-shaped, closed, not phloyophorous but sometimes pyrifer, pores. We really noticed at times some closed pores; they do not present however any inflation of vesyculifer type, and are besides always filled with detrital dark matter. This last fact confirms, in our opinion, that all the pores opened to the exterior, though through a partially calcifiable peripherical branche-membrance. »

Measurements:

« As the calcification in usually total, the value s has been supplied by thickness of the wall occupied by the branches. Of the original hollow, in fact, we noticed some traced only. »

 original description of Aciculella ogilvie-gordonae (Elliott, 1971): « (.) »

5. Remarks

6. Stratigraphic range

Late PERMIAN (Praturlon, 1963; Elliott, 1971; ? Mirković, 1986; Noé, 1987; Broglio Loriga et alii, 1988)

7. Real distribution

Italy (Praturlon, 1963; Elliott, 1971; Noé, 1987; Broglio Loriga et alii, 1988), ? Yugoslavia (? Mirković, 1986)

8. Paleoecology