Fasciphyllidae

Family Fasciphyllidae Soshkina, 1954 Fasciphyllum Schlüter, 1885

Type species: Fascicularia conglomeratum Schlüter, 1881 , from the lower Givetian , Middle Devonian , Loogh Formation of the Eifel Hills, Germany .

Diagnosis (after Schlüter 1885).—Phaceloid colonies with cylindrical corallites. Septa dilated in periphery to form prominent stereozone. Major septa reaching the axis, minor septa short. Tabulae widely spaced, complete, flat or sagging. One row of vertically elongated dissepiments. Septal trabeculae slender.

Remarks.—There is a consensus on the synonymy of the genera Fasciphyllum Schlüter, 1885 , and Battersbya Milne-Edwards & Haime, 1851 . However, Schröder and Lütte (1999) and McLean (2018) accept Batterbya, based on the lectotype of Battersbya inaequalis Milne-Edwards & Haime, 1851 , as valid, whereas Coen-Aubert (1992), and Zhen and Jell (1996) prefer to use the name Fasciphyllum , based on Fasciphyllum conglomerata Schlüter, 1881 , as the type material of the latter is better preserved and more precisely constrained stratigraphically than the British species. If it is an agreement on F. conglomeratum being a junior synonym of B. inaequalis , the species F. varium is very different (larger corallites, dissepimentarium more complex, stereozone less developed, mode of increase) as documented by Schröder and Lütte (1999). Hence, this species is probably not congeneric with B. inaequalis and a new genus name would be required. Meanwhile, we use here the name “ Fasciphyllum ” varium for the present material.

“ Fasciphyllum ” varium Schlüter, 1889

Fig. 7A–D View Fig .

Material.—Nine fragments (PAULg. RUS I.2, II.8, III.1, 2, 5, 7, 11, PAULg.BAR II.4, 5, and PAULg. WAK.1) of colonies from the Middle Devonian (upper Eifelian–?lower Givetian) Russ Conglomerate, Russ I, II, and III outcrops, two from Barembach and one from Wakenbach, France.

Description.—Fasciculate colonies with small cylindrical corallites growing parallel to each other, some colonies display polygonal corallites where offsets remain attached to parent corallites. Increase lateral mostly non-parricidal, though axial division is suspected in one specimen. Corallites 4.5–6 mm in diameter (tabularium 3.5–4 mm), having 16–18 septa of both orders. Major septa long, reaching the axis, some of them connecting, or slightly withdrawn, leaving a free space < 1 mm wide in the axial part of the corallite. Major septa straight and smooth, or slightly tortuous in the axial part. Minor septa short, not reaching the margin of the tabularium, most commonly reduced to septal crests on the wall. Base of septa thickened with the wall. In rare, well-preserved specimens, a thin dark median line is visible in the septa. Wall up to 0.4 mm thick. Dissepimentarium very narrow, made of one, commonly incomplete row of concentric interseptal dissepiments, rarely a second incomplete row in large corallites, but missing in the small ones. In longitudinal section, dissepiments globular declined towards the axis at 40–50°, the second row being formed of larger dissepiments declined at 70°. Tabulae flat or slightly concave, mostly complete, densely packed.

Remarks.—Despite the poor preservation of the material, the characteristics of “ F.” varium are recognisable, notably the long and thin major septa, short minor septa, the dissepiments variable in size and shape, and the sagging tabulae.

Geographic and stratigraphic range.—In the Northern Vosges, the species is present in the Russ Marble in Russ, Barembach and Wakenbach. The species is abundant in the Eifelian of Belgium and the Eifel Hills, Germany ( Schröder and Lütte 1999; Denayer 2023) and possibly in the Givetian of Moravia ( Battersbyia cf. anisactis in Galle 1981, with several rows of dissepiments)

“ Fasciphyllum ” sp.

Fig. 7E, F View Fig .

Material.—Three fragments (PAULg. RUS III.4, 6, 12) of small colonies from the Middle Devonian (upper Eifelian–

lower Givetian) Russ Conglomerate, Russ III outcrop, France.

Description.—Small fasciculate colonies with cylindrical corallites growing parallel to each other, 4–4.5 mm in diameter ( 3.5–4 mm for the tabularium). Increase lateral non-parricidal. On average, 15–16 septa of each order. Major septa long but withdrawn from the axis, straight and smooth. Minor septa short, reaching the margin of the tabularium. Wall 0.4 mm thick. Dissepimentarium made of two rows of concentric and crossed interseptal dissepiments, the inner row being usually thickened. In longitudinal section, dissepiments variable in shape and size, declined towards the axis at 40–60°, the inner row being more irregular. Tabulae complete and flat.

Remarks.—Three colonies described herein differ from Fasciphyllum ” varium by their smaller diameter their number of septa slightly lower, but, above all, their dissepimentarium more developed and more complex.

The species is only known from Russ in the northern Vosges.