Spasskyella Tsyganko, 1977

Genus Spasskyella Tsyganko, 1977

Type species: Spasskyella pershinae Tsyganko, 1977 , from the Givetian , Middle Devonian, of the western side of the Polar Ural Mountains .

Diagnosis (after Tsyganko, 1977). — Fasciculate colony with cylindrical corallites displaying longitudinal rugae on the wall. Septa very short or not developed, minor and major septa indiscriminated. Base of septa triangular, included in the lamellar stereoplasm of the wall. Dissepimentarium unstable, made of one or two uncomplete rows of vertical dissepiments. Tabulae horizontal and flat.

Remarks.—These simple colonies have few characteristics for discussing the systematic attribution. The poor development of the septa and simple tabulae are commonly observed in Pseudoamplexus Weissermel, 1897 , Aphyllum Soshkina, 1937 , and Tabularia Soshkina, 1937 . However, the latter are all solitary genera. The genus Pycnostylus Whiteaves, 1884 , is a colonial form close to Pseudoamplexus and differs from Spasskyella Tsyganko, 1977 , by its parricidal axial increase where four offsets form simultaneously, whereas Spaskyella displays non-parricidal lateral increase. Synaptophyllum Simpson, 1900 , is relatively simple in morphology, but differs by its regularly spaced mesa-shaped tabulae and longer (and more stable) septa. Cyathopaedium Schlüter, 1889 , has very irregular and sparse tabulae. Such a simple morphology is also observed in pseudocolonies of “ Amplexus ” flo­ rescens Počta, 1902, as figured by Berkowski (2006) but the latter, besides its gregarious habitus, differs by the more conical morphology of the corallites.

Tsyganko (1981) classified Spasskyella into the Disphyllidae based on the morphology of the septal trabeculae and cuneiform base of the septa included in the external wall. Based on the same argument, he included the species figured by Oliver (1976) Disphyllum ? stummi ( Oliver, 1971) and Disphyllum ? rectiseptatum ( Röminger, 1876) in Spasskyella . However, in those two species, the tabulae are commonly divided and convex. Moreover, the dissepimentarium is well developed (up to three rows in D.? stummi) and made of globose dissepiments (cf. Oliver 1976: pls. 30 and 44). Hence, the two American species are here excluded from Spasskyella .

The colonies doubtfully attributed to Synaptophyllum by Rodríguez-García (1978) present horizontal tabulae and not the mesa-shaped tabulae that are characteristic of the genus. Though? Synaptophyllum oliveri Rodríguez-García, 1978 , displays rather long septa, they could be included in Spaskyella after revision of the type material.

Spasskyella sp.

Fig. 8A, B View Fig .

Material.—One fragment of colony and numerous isolated corallites (PAULg. ROT.1 and 6) form the Middle Devonian (upper Eifelian–?lower Givetian) Russ Conglomerate, La Rotonde de Schirmeck outcrop, France.

Description.—Small phaceloid colony with relatively densely-packed cylindrical corallites 5 to 5.5 mm in diameter, without any connecting structure. Septa developed in less than 10% of the corallites. Where present, there are up to 20 short septa, less than 0.5 mm long, but rarely on both sides of the corallite. Distinction between minor and major septa not possible. Where not developed, small triangular thickening on the inner edge of the wall might represent the base of the septa. External wall 0.2–0.5 mm thick, straight and smooth. One incomplete row of vertical vesicular dissepiment observed. In longitudinal section, tabulae flat or slightly concave, parallel to irregularly arranged, separated by 0.3 to 1 mm. Increase lateral with one or two offsets.

Remarks.—Though the available material is limited, the specimens from Rotonde de Schirmeck differ from the type-species and only other described species of Spasskyella by the size of the corallites ( 7.5 mm in diameter in the Russian species). The French specimens are closer in size to the possible Spaskyella oliveri Rodríguez-García, 1978 , but the latter has longer septa.

Besides the type-species described from the Givetian strata of the Urals Mountains, and a possible occurrence in the Emsian of Ossa Morena, the French occurrence is the second report of the genus in NW Europe.