Rarytkinia polonica

Halamski, Adam T., 2013, Latest Cretaceous leaf floras from southern Poland and western Ukraine, Acta Palaeontologica Polonica 58 (2), pp. 407-443 : 426-428

Rarytkinia polonica (Karczmarz and Popiel in Malicki et al., 1967) comb. nov.

Figs. 2E, 10B , 11B, D, 12J.

1907 Populus hyperborea Heer ; Nowak 1907a: 50–51, pl. 2: 17.

part 1967 Ficus polonica Kar. et Pop. , n. sp.; Malicki et al. 1967: 228–229, pls. 7: 22, 8: 23.

1975 Ficus polonica Kar. et Pop. ; Kohlman−Adamska 1975: 164, 166, pl. 1: 3.

Basionym : Ficus polonica Karczmarz and Popiel in Malicki et al., 1967.

Type material: Holotype MZ VII/33/32, an incomplete leaf from Krasnobród; paratype from Kosobudy ( Malicki et al. 1967: pl. 8: 23; MZ VII/33/30) is unidentifiable.

Material.—Four incomplete leaves: L PB−K.20 from Potylicz, JS 3, ZPAL Pl 4/1/2, 4 from Krasnobród.

Description.—Blade attachment marginal, laminar size mesophyll (length up to at least 10 cm), laminar length to width ratio 1.8:1, laminar shape elliptic, blade medially symmetric, basal width asymmetric, margin unlobed with dentate and serrate teeth. Apex not preserved, base angle obtuse, base shape convex.

http://dx.doi.org/10.4202/app.2011.0024

Primary venation pinnate craspedodromous. The first two pairs of secondaries depart under an angle of 70–90 °, whereas all the following ones keep a uniform angle of 50–60 °. Spacing of secondaries slightly decreasing distally, attachment excurrent. Secondaries sometimes bifurcate; no intersecondaries. Tertiaries poorly preserved.

Tooth spacing irregular with one order of teeth and two to three teeth per cm. Teeth low, sinus shallow. Teeth either perpendicular to the leaf margin or directed distally. Sinus shape mostly rounded, tooth shape biconcave.

Remarks.—The discussed poorly preserved leaves are included in Rarytkinia on account of their shape, serration, and venation. In particular, the lowest veins depart from the midvein at a much higher angle, wherefore they are shorter than the following ones, a character shared with the R. terechovae , the type of the genus. The differences between R. polonica and R. terechovae are difficult to define given the great variability of both species ( Golovneva and Abramova 1990) and the poor preservation of our material. However, the serration of our taxon seems much finer.

The affinities of this form genus are unknown. It is known from the Maastrichtian to Danian of the Koryak Mountains, Russian Far East: R. terechovae and R. amaamensis Moiseeva, 2008 ( Golovneva and Abramova 1990; Moiseeva 2008) and from the Palaeocene of Alaska ( Rarytkinia sp. , Early Sagwon flora; Herman et al. 2009). R. quercifolia Golovneva, 2000 from Greenland is excluded following Kvaček (2010). R. polonica is therefore the oldest and the southernmost known species of an otherwise northern genus.

Stratigraphic and geographic range.—Krasnobród, Potelych, late Campanian.

Figures

Fig. 10. Reconstructions of leaves of the most characteristic taxa of the late Campanian flora of the studied area (not to scale). A. Eudicot Debeya paulinae sp. nov. B. Dicot Rarytkinia polonica (Karczmarz and Popiel in Malicki et al. 1967) comb. nov. C. Eudicot Debeya haldemiana (Debey ex de Saporta and Marion, 1873) Knobloch, 1964. Drawings by B. Waksmundzki.