Grewiopsis sp.

Halamski, Adam T., 2013, Latest Cretaceous leaf floras from southern Poland and western Ukraine, Acta Palaeontologica Polonica 58 (2), pp. 407-443 : 425

Grewiopsis sp.

Fig. 11A.

Material.—A single fragmentary leaf (part and counterpart) from Krasnobród, ZPAL Pl 4/1/7.

Description.—Leaf attachment petiolate, marginal blade attachment. Laminar size notophyll (width probably slightly exceeding 60 mm; length unknown, well over 50 mm). Laminar shape probably rounded, asymmetric; base probably asymmetric, apex not preserved; base angle obtuse. Margin entire in basal part, otherwise not preserved.

The single primary vein, 2 mm wide along all its length, is curved at about 10 ° (difference between directions at base and at the extremity of the preserved part). Major secondary veins probably semicraspedodromous, their attachment excurrent, spacing gradually decreasing distally, angle decreasing distally from ca. 50 ° to ca. 20 ° on the convex side of the midvein and from ca. 30 ° to ca. 20 ° on the concave side. The basal two secondaries are notably thinner than those closer to the apex. Minor secondaries departing from the first secondary at an angle of <10 °, from the second one at ca. 20 °, from the third at ca. 50 °, all curving inwards. Higher order venation not preserved.

Remarks.—The described leaf is similar to Grewiopsis credneriaeformis de Saporta, 1868 and to G. tiliacea de Saporta, 1868 , both from the Eocene of Sézanne ( de Saporta 1868: pls. 12: 7, 11: 9) in having a pair of weak first secondaries, a finely serrate margin, a slightly asymmetric base and a curved midvein (last two characters in the former species). The affinities of the form genus Grewiopsis are unknown. Cretaceous species referred to this genus were described from the mid−Late Cretaceous of the Vilui Basin of Yakutia ( Budantsev 1968; age after Spicer 2003) and from the Santonian of Kamchatka ( Herman and Lebedev 1991). Out of them, G. styracifolia Budantsev, 1968 and G. akhmetjevii Vachrameev and Herman, 1991 are similar to the Polish species in shape, overall venation pattern and fine serration of the margin; the former differs in symmetric base and straight midvein and the latter has a finer midvein and a different teeth form.

Dicotylophyllum varienerve ( Drygant, 1998) comb. nov. from Pidtemne (see below) has a midvein incurved similarly to that of Grewiopsis sp. The secondaries, however, are more rarely spaced and depart at a higher and more constant angle.