Dryophyllum westerhausianum ( Richter, 1904 ) Halamski and Kvaček 2020

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 : 825-826

Dryophyllum westerhausianum ( Richter, 1904) Halamski and Kvaček comb. nov.

Figs. 7–9 , 15C .

1904 Bignonia Westerhausiana n. sp.; Richter 1904: 20, pl. 2: 1–6. non 1977 Dewalquea westerhausiana ; Rüffle and Knappe 1977: 279,

pl. 4: 1.

Basionym .— Bignonia westerhausiana Richter, 1904 ( Richter 1904: 20; pl. 2: 1–5; see Appendix 4).

Material.—Otok, Assemblage 6, lower–middle Santonian: MB.Pb.2008/0262, 2018/0039. Rakowice Małe, Assemblage 6, lower–middle Santonian: MB.Pb.2008/0256. Ulina, Assemblage 6, lower–middle Santonian: MGUWr 1699p.b, 1715p, 2707p, 2709p, 5593p, 5616p.a, 5617–5619p, 5637p, 5651p (mostly coll. Goeppert), MB.Pb.2008/0346, 0360, 0368, 2018/0029, 0045.

Description.—Leaf compound, trifoliolate (Fig. 8E). Leaflets notophyll to mesophyll (maximal recorded length ca. 10 cm, Fig. 9C ; estimated total length over 15 cm), petiolulate, blade attachment marginal; base shape decurrent; apex poorly preserved, straight (Fig. 8A, C). Blade shape oblong, seldom ovate, length-to-width ratio ca. (3.5–)4–5(–6). Margin unlobed, serrate. Teeth regularly spaced, ca. 1–2 per cm, sinus shape rounded, proximal flank flexuous, distal flank concave ( Fig. 9A, B ).

Primary venation pinnate, midvein strong. Major secondaries craspedodromous, spacing irregular, 1–4 per 2 cm, attachment excurrent, angle to midvein variable, 50–70(–80°). Intersecondaries none. Tertiaries percurrent, straight to sinuous ( Fig. 9B ). Quaternaries poorly preserved, reticulate?

Remarks.—The discussed species is included in Dryophyllum on account of several architectural features, among which marked asymmetry of lateral leaflets ( Halamski and Kvaček 2015: pl. 4: 1, 3, 4) and lack of intersecondaries allow the distinction with Debeya Miquel, 1853 . The type species of the latter, Debeya serrata Miquel, 1853 , from the Maastrichtian of Kunrade (Limburg, Netherlands), pos- sesses numerous intersecondaries ( Miquel 1853: pl. 1: 1) and lateral leaflets differing only weakly from the median one.

Rüffle and Knappe (1977) interpreted Bignonia westerhausiana Richter, 1904 , as a platanoid. However, such an interpretation is based on a specimen from another locality not given, but not Westerhausen; Rüffle and Knappe 1977: 279) and of manifestly different architecture (pentafoliolate and not trifoliolate; Rüffle and Knappe 1977: pl. 4: 1), so is likely to be erroneous.

Coniacian Dryophyllum geinitzianum ( Goeppert, 1844) Halamski and Kvaček, 2015 , is very similar to the discussed species in leaf architecture, venation pattern, and serration of the margin; the main difference is in the leaflets of the former being less elongate (length-to-width ratio 2.5–4; Halamski and Kvaček 2015). The similarity of D. westerhausianum to D. geinitzianum was stressed already by Richter (1904: 20).

Ternstroemites longifolius ( Friedrich, 1883) Rüffle and Krutzsch, 2005 , from the Maastrichtian of Eisleben has similar serration of the margin, but secondaries are much denser and brochidodromous. It is possible that Aralia veatchii Knowlton, 1917 , from the Frontier Formation of Wyoming should be interpreted as a trifoliolate leaf (see especially Knowlton 1917: pl. 39) analogous to Dryophyllum westerhausianum .

“ Dryandroides ” quercinea Velenovský, 1883 , described from the Coniacian of Česká Lípa is distinguished from Dryophyllum by narrower leaves with stronger teeth (Halamski and Kvaček 2016) and the presence of intersecondaries. For a discussion on the ecological segregation of the two species, see below (group Fagofolia, Dryandroides ).

Stratigraphic and geographic range.— Saxony, Westershausen (Santonian); Lower Silesia, Assemblage 4 (a single specimen; upper Coniacian?– lower Santonian ?) and Assemblage 6 (lower–middle Santonian) .

Figures

Fig. 7. Taphonomy of the fagalean angiosperm Dryophyllum westerhausianum (Richter, 1904) Halamski and Kvaček comb. nov. from Ulina, North Sudetic Basin, Lower Silesia, Poland, Assemblage 6 (lower–middle Santonian). A. Three leaflets (arrows indicate the two largest ones possibly from the same leaf) and several incomplete or fragmentary Laurophyllum? sp. MB.Pb.2008/347. B. Four fragmentarily preserved leaflets (arrows indicate the two largest ones possibly belonging to the same leaf) MGUWr 5617p.

Fig. 9. Fagalean angiosperm Dryophyllum westerhausianum (Richter, 1904) Halamski and Kvaček comb. nov. from Ulina, North Sudetic Basin, Lower Silesia, Poland, Assemblage 6 (lower–middle Santonian). A. Fragmentary leaflet MGUWr 5619p showing venation and serration. B. Enlargements of venation of fragments of two leaflets MB.Pb.2008/339 (see the entire specimen in Fig. 8C). C. Probable trifoliolate leaf MB.Pb.2008/0342 with two fragmentarily preserved leaflets.

Fig. 15. Semi-schematic reconstructions of the presumed main forest-forming angiosperms in the Coniacian–Santonian of Lower Silesia, Poland. A. Dewalquea aff. gelindenensis de Saporta and Marion, 1873 (compare Fig. 12A, B). B. Platanites sp. 1 (compare Fig. 16C; lateral leaflets hypothetical, supposed similar to those of Platanites marginatus, see Johnson 1996: fig. 86). C. Dryophyllum westerhausianum (Richter, 1904) Halamski and Kvaček comb. nov. (compare Fig. 8C, E). D. Platanites willigeri Halamski and Kvaček, sp. nov. (compare Fig. 14A, C). E. Dewalquea insignis Hosius and von der Marck, 1880 (compare Fig. 10F). F, G. Ettingshausenia sp. 1 (compare Fig. 13G, D). Not to scale. Drawings by Bogusław Waksmundzki.