Autunia naumannii ( Gutbier, 1849 ) Kerp, 1988

Boyarina, Natalya, 2010, Late Gzhelian pteridosperms with callipterid foliage of the Donets Basin, Ukraine, Acta Palaeontologica Polonica 55 (2), pp. 343-359 : 346-348

Autunia naumannii ( Gutbier, 1849) Kerp, 1988

Figs. 3G, I, K, 4.

1849 Sphenopteris naumannii sp. nov.; Gutbier 1849: 11, pl. 7:1, 4, 6. 1881 Callipteris naumannii ( Gutbier, 1849) ; Sterzel 1881: 255–257. 1988 Autunia naumannii ( Gutbier, 1849) ; Kerp 1988: 305–308, pl. 26, 27.

Material.—Four fragments of the upper frond parts— SNM PMC 2216/67, SNM PMC 2216/42, SNM PMC 2216/25, SNM PMC 2216/28; one fragment of the middle frond part — SNM PMC 2216/58; three apical portions of fronds— SNM PMC 2216/24, SNM PMC 2216/43, and SNM PMC 2216/ 41 in association with the isolated seed; 26 isolated pinnae, including a pinna in association with an isolated megasporophyll— SNM PMC 2216/82. Five fragments of ovuliferous organs and many isolated megasporophylls, polliniferous organs and seeds. The most informative: ovuliferous organs— SNM PMC 2216/68, SNM PMC 2216/69, SNM PMC 2216/71; isolated megasporophylls and seeds— SNM PMC 2216/83, SNM PMC 2216/64; and an isolated polliniferous organ— SNM PMC 2216/72.

Description.—The frond fragments are bipinnate ( Figs. 3K, 4A, C, L). The upper parts of the fronds show a single ( Figs. 3G, K, 4A, E, H) or double overtopping of the primary rachis ( Fig. 4L); as result of the latter, the frond apically has the slightly zigzag−shaped primary rachis. Pinnules are ovate to prolonged and decurrent basiscopically. They are 6 to 12 mm long and 3 to 6 mm wide. The lateral pinnule margins vary from crenulate and lobed to dissected. The midvein is thin, running to the middle of the pinnule. The dissected pinnules have three−seven segments and the pronounced midvein runs to the base of the apical segment. The lateral veins bifurcate in the apical part of each segment. Pinnule segments are wedge−shaped and slightly arcuate. Segments with a pronounced vein show an emarginate apex ( Fig. 3I).

Two frond fragments have prolonged pinnules in the apical portion above the overtopping of the primary rachis ( Figs. 3G, 4C). These prolonged pinnules with the crenulate margins, a thick midvein and closely spaced, bifurcated lateral veins show the “polymorpha”−aspect, whereas the ultimate order pinnae bear pinnules more typical for Autunia naumannii ( Fig. 4C).

In association with the Autunia naumannii foliage, ovuliferous organs, isolated megasporophylls and seeds were found. The ovuliferous organs are attached to the rachis reaching a width of 10 mm ( Fig. 4B). The ovuliferous organs have axes up to 2–4 mm wide and bear the closely spaced megasporophylls ( Fig. 4D, H). The megasporophylls are bilaterally symmetrical, broadly flabelliform, 7–9 mm wide, with strong, radiating ribs. The anterior margins of the megadoi:10.4202/app.2009.0020

sporophylls are crenulate to slightly lobed. One or two ovules are sometimes attached to the megasporophylls ( Fig. 4F). The seeds are small, up to 4–5 mm long and 3–3.5 mm wide, ovoid, flattened ( Fig. 4G, I).

Isolated polliniferous organs are small and consist of the basally fused and apically free sporangia ( Fig. 4J). The sporangia are elongated elliptic, 5–6 mm long.

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

Genera supposed to be assigned to Peltaspermales Taylor, 1981