Protopteris Sternberg, 1838

Halamski, Adam T., Kvaček, Jiří, Svobodová, Marcela, Durska, Ewa & Heřmanová, Zuzana, 2020, Late Cretaceous mega-, meso-, and microfloras from Lower Silesia, Acta Palaeontologica Polonica 65 (4), pp. 811-878 : 820

Genus Protopteris Sternberg, 1838

Type: Protopteris punctata (Sternberg, 1820) Presl in Sternberg, 1838 ≡ Lepidodendron punctatum Sternberg, 1820 ; Peruc-Korycany Formation, Cenomanian, Upper Cretaceous; Kounice, Bohemia.

Protopteris punctata (Sternberg, 1820) Presl in

Sternberg, 1838

1820 Lepidodendron punctatum ; Sternberg 1820: 20, 23, pl. 4: 1.

2013 Protopteris punctata (Sternberg) C. Presl in Sternberg; Greguš et al. 2013: 72–73, pl. 1: 1–8; pl. 2: 1 [ubi syn.].

Material.—Unknown locality in the Lwówek Śląski area, Assemblage 3, Coniacian: MGUWr 7398p.

Description.—Sandstone cast of a stem showing helically arranged leaf scars with typical traces of vascular bundles and adventitious roots among them. For a detailed description see Greguš et al. (2013).

Remarks.—The exact provenance of the stem fragment MGUWr 7398p, which is the only specimen of P. punctata from Silesia, is uncertain. It is labelled “Löwenberg” (now Lwówek Śląski), but possibly this should be understood rather as an indication of a region, and not of a precise locality. It is interesting to note, however, that it is quite unlikely that the age of MGUWr 2885p be Cenomanian, but rather either Turonian or Coniacian ( Greguš et al. 2013); it is thus younger than all Bohemian material of this species.

Stratigraphic and geographic range.—Cenomanian, Bohemia; Coniacian, Silesia ( Greguš et al. 2013: 72).

Protopteris singeri ( Goeppert, 1836b) Presl in

Sternberg, 1838

1836 Caulopteris singeri ; Goeppert 1836b: 449, pl. 41: 1, 2.

2013 Protopteris singeri (Göppert) C. Presl in Sternberg; Greguš et al. 2013: 73–74; pl. 2: 2–5 [ubi syn.].

Material.— Żeliszów, Assemblage 3, Coniacian: MGUWr 2885 p.b (holotype), MGUWr 2885 p.a.

Description.—Sandstone casts of stems covered by helically arranged leaf scars. For a detailed description see Greguš et al. (2013).

Remarks.—This species is known solely from two specimens. According to the results of a more detailed field investigation, their age, given as Turonian–Coniacian by Greguš et al. (2013), is more probably Coniacian.

Stratigraphic and geographic range.— Type locality only.

Order and family unknown

Genus Cladophlebis Brongniart, 1849

Type: Cladophlebis albertsii ( Dunker, 1846) Brongniart, 1849 ≡ Neuropteris albertsii Dunker, 1846 ; Lower Cretaceous, northern Germany.

Remarks.—It should be noted that C. albertsii , the type of the genus, has petiolulate (“neuropteridic”) pinnules. The original specific diagnosis is somewhat confused on that matter, referring to “pinnulis… sessilibus” ( Dunker 1846: 8). It is clear, however, that this should not be understood as meaning sessile pinnules, as the description of the shape of the base follows: “basi rotundatis vel subcordatis”. The figure showing single points of attachment of pinnules to the rachis ( Dunker 1846, pl. 7: 6a) is also clear, despite the very short petiolule.

It follows that the genus name Cladophlebis should not be applied to fernlike foliage with broad-based pinnules, as was done, among others, by Harris (1961) and Miller and Hickey (2008). A complete revision of Cladophlebis is, however, beyond the scope of the paper.

Cladophlebis sp. 1

Fig. 4B .

Material.—Rakowice Małe, Assemblage 5, late Coniacian– early Santonian?: MB.Pb.2018/0067.

Description.—The available material consists of two specimens, one ( Fig. 4B ) relatively small-sized but sufficient to partly decipher the architecture of the frond, the other showing solely two pinnules.

Frond bipinnate (preserved length ca. 20 mm, preserved width ca. 17 mm), rachis of the (n-1)-th order ca. 1.5 mm thick, pinnulae inserted on rachises of both n-th and (n-1)-th order; the two inserted on the rachis of the (n-1)-th order lanceolate, the single one entirely preserved among those on the rachis of n-th order with rounded apex. Angle between the midvein of the pinnule and the rachis 50–90° (the difference between two pinnules on either side of the rachis). Pinnules shortly petiolulate, with a broad base, straight midvein and forking secondaries, 2.5–3.5 times as long as wide.

Remarks.—The fragmentary character of the studied material precludes any detailed comparison. Cladopteris albertsii is generally similar to the material from Rakowice Małe, with the exception of apparently possessing more curved midveins. Cladophlebis frigida ( Heer, 1882) Seward, 1926 , from the Lower Cretaceous of Greenland has longer pinnules ( Heer 1922: pl. 10: 1–4). Cladophlebis sp. from the lower Maastrichtian? of the southern border of the Holy Cross Mountains (Central Poland) has elliptic pinnules (Halamski 2013). In Cladopteris gosauensis Kvaček and Herman in Herman and Kvaček, 2010, from the Campanian of Grünbach pinnules are sessile and their length-to-width ratio does not exceed 2 ( Herman and Kvaček 2010).

Figures

Fig. 4. Late Coniacian?–early Santonian? ferns from the North Sudetic Basin, Lower Silesia, Poland. A. Cladophlebis? sp. 2, fragment of a pinna MGUWr 7556p, Żeliszów, Assemblage 5. B. Cladophlebis sp. 1, fragment of a pinna MB.Pb.2018/0067, Rakowice Małe, Assemblage 5. C. Coniopteris? sp., frag- ment of a pinna MB.Pb.2018/0006 (rachis arrowed), Rakowice Małe,Assemblage 5. D–G. Konijnenburgia cf. galleyi (Miner, 1935) Kvaček and Dašková, 2010, Assemblage 4. D. Fragment of a pinna MB.Pb.2018/0062, Rakowice Małe. E. Accumulation of isolated pinnules MB.Pb.2008/373.2a (E1) and enlargement of a pinnule with sori (E2), Żerkowice. F. Two isolated pinnules MB.Pb.2008/373.1 (F1) and enlargement of the longest pinnule in the studied material with sori (F2), Żerkowice. G. Fragment of a pinna MB.Pb.2008/373.2b, Żerkowice.