Autunia conferta (Sternberg, 1826) Kerp, 1988

Boyarina, Natalya, 2010, Late Gzhelian pteridosperms with callipterid foliage of the Donets Basin, Ukraine, Acta Palaeontologica Polonica 55 (2), pp. 343-359 : 346

Autunia conferta (Sternberg, 1826) Kerp, 1988

Fig. 3A–F, H, J.

1826 Neuropteris conferta sp. nov.; Sternberg 1826, I, 4: 17.

1833 Neuropteris conferta Sternberg, 1826 ; Sternberg 1833, II, 5–6: 75, pl. 22: 5.

1849 Callipteris conferta (Sternberg, 1826) ; Brongniart 1849: 73.

1907 Callipteris conferta (Sternberg, 1826) Brongniart, 1849 ; Gothan 1907a: 1–18, text−figs. 1–6.

1988 Autunia conferta (Sternberg, 1826) ; Kerp 1988: 258–305, pl. 1–25.

Material.—Three fragments of the upper parts of the frond— SNM PMC 2216/66, SNM PMC 2216/2, SNM PMC 2216/81; two fragments of the middle frond parts— SNM PMC 2216/23 and SNM PMC 2216/80; one basal portion of a frond— SNM PMC 2216/77; one fragment of an immature frond— SNM PMC 2216/79; one fragment of a pinna— SNM PMC 2216/78.

Description.—The fragments of the fronds are bipinnate ( Fig. 3A, C, F). The apical part of the fronds shows the overtopping of the primary rachis ( Fig. 3C, F). The pinnules are ovate and decurrent. They vary in a length from 4 to 10 mm. The lateral margins of the pinnules vary from straight to slightly lobed. The small pinna, likely of an immature frond, has very small pinnules folded by halves along the midvein ( Fig. 3E). The midvein is strong, decurrent and running to 3/4 of the pinnule length. The lateral veins are slightly pronounced, single or once bifurcated. The intercalary pinnules, up to 4–6 mm long and 2–3 mm wide.

Stratigraphic and geographic range.—Upper Stephanian (Upper Carboniferous) and Autunian (Lower Permian) of Europe.