Dewalquea insignis Hosius and von der Marck, 1880

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 : 831-834

Dewalquea insignis Hosius and von der Marck, 1880

Figs. 10E–F, 11, 15E.

1880 Dewalquea insignis Hos. & v. d. Marck; Hosius and von der

Marck 1880: 172–173, pls. 32: 111–113, 33: 109, 34: 110. 2009 Debeya haldemiana ; Mohr 2009: text-fig. 11. 2013 Debeya insignis ( Hosius and von der Marck, 1880) Knobloch,

1964; Halamski 2013: in part: 421–422, figs. 7A, C, 8?, 9A?, F?

Material.—Bolesławiec, Assemblage 8, lower–middle Santoni an: MB.Pb.2008/0323, 0325; MGUWr 1699p.b, 5639p.

Description.—Leaf compound, pedate, consisting of up to presumably nine subsessile to shortly petiolulate leaflets; leaf most probably petiolate but petiole not preserved in the studied material. Leaflets lanceolate, 11–18 mm wide, in the only subcomplete specimen median leaflet 18 mm wide, then width gradually diminishing towards the external leaflets 11 mm wide; preserved length up ca. 8 cm, estimated length up to ca. 12 cm, estimated length-to-width ratio ca. 5–8. Margin serrate, teeth ca. 2 per cm (Figs. 10F 4, F 5, 11A 2), but often not observable, proximal side straight, distal side concave. Venation pattern pinnate ( Fig. 11B ), camptodromous or craspedodromous (interpretation uncertain); midvein thick, secondaries departing at an angle of ca. 45–60°, then curving towards the apex, possibly sometimes entering the teeth.

Remarks.— Dewalquea insignis was described from the Campanian of Haldem (Westphalia) by Hosius and von der

→ Fig. 10. Late Cretaceous representatives of the eudicot angiosperm Dewalquea from the North Sudetic Basin, Lower Silesia, Poland. A–D. Dewalquea haldemiana Debey ex de Saporta and Marion, 1873 . A. Apical part of an isolated leaflet MB.Pb.2018/0084, Rakowice Małe, Assemblage 4 (upper Coniacian?–lower Santonian?). B. Fragment of a compound leaf MB.Pb.2008/066, Rakowice Małe, Assemblage 4 (upper Coniacian?–lower Santonian?). C. Incomplete compound leaf MGUWr 1699p.a, Bolesławiec, Assemblage 8 (Santonian). D. Isolated leaflet MB.Pb.2008/0320 showing venation, Rakowice Małe, Assemblage 4 (upper Coniacian?–lower Santonian?). E, F. Dewalquea insignis Hosius and von der Marck, 1880 , Bolesławiec, Assemblage 8 (Santonian). E. Incomplete leaf MGUWr 1699p.b, enlargement of a leaflet showing venation. F. Incomplete leaf MB.Pb.2008/323 (specimen figured by Mohr 2009: fig. 11 as Debeya haldemiana ); general view (F 1), enlargement of a leaflet under different lightning to show venation (F 2), basal part (F 3), two leaflets (F 4, F 5) showing teeth (arrowed).

Marck (1880) who interpreted the original material as having leaves with serrate margins and this condition should be retained, despite the reservations expressed by Halamski 2013) when selecting the lectotype. The venation pattern of the type material is pinnate craspedodromous according to Hosius and von der Marck (1880); this character was not observable during its examination by ATH in 2012 Halamski 2013: fig. 7A, C). The venation pattern of leaves from Lower Silesia is similar to that described by Hosius and von der Marck (1880). Dewalquea aquisgranensis de Saporta and Marion, 1873 , originally described from the Aachen Formation (sables d’Aix-la-Chapelle, Robaszynski et al. 2002), the age of which is middle Santonian to probable earliest Campanian ( Batten and Li 1987; Batten et al. 1988; Streel et al. 1994; the confusion resulting from deal- ing with a Cretaceous plant in a monograph devoted to Paleocene flora was stressed already by Stockmans 1946: 28–29), has the same leaf organisation and similarly shaped leaflets, but the venation pattern is very different, with secondaries forming numerous anastomoses (de Saporta and Marion 1873: pl. 8: 5–7). Dewalquea pulchella Knowlton, 1917 , from the Frontier Formation of Wyoming ( USA) is similar in shape, with the exception of leaflets being subsessile and 5(–6) in number.

The plant material from the Campanian to Maastrichtian of eastern Poland reported under D. insignis by Halamski 2013: fig. 9A, F) is entire-margined and probably represents different species. D. haldemiana , the most common representative of Dewalquea in the studied material, has narrower and entire-margined leaflets.

Stratigraphic and geographic range. —Santonian of the Liège-Limburg Basin, Belgium and Lower Silesia, Poland.

Dewalquea aff. gelindenensis de Saporta and Marion, 1873

Figs. 12, 15A.

Material.—Bolesławiec, Assemblage 8, lower–middle Santon ian: MGUWr 2880p (coll. Jonas 1885; figured by Roemer 1889: pl. 12: 3 as Debeya haldemiana ), MGUWr 2881p (coll. F. Roemer 1886), MGUWr 6150p.

Description.—Leaves compound, pedate, petiolate, of (five to?) seven petiolulate leaflets. Petiole distally widened

Fig. 10A 3). Petiolules short(never exceeding 5mm).Leaflets symmetric, with marginal blade attachment, notophyll, up to ca. 25 mm in width, preserved length ca. 7 cm, estimated length> 10 cm, estimated length-to-width ratio 4–5. The median leaflet always the widest, the lateral ones narrower; sometimes, but apparently not always, leaflet width gradually decreasing from the median leaflet towards the external ones. Base cuneate, apex possibly straight. Margin unlobed, untoothed (Fig. 10A 2, XB 3). Venation pattern pinnate camptodromous (Fig. 10A 2); midvein stout; secondaries excurrent, departing at (45–)60–90°, gently curving, quite irregularly spaced, 1–3 per cm; finer venation not preserved.

Remarks.—The described material is distinguished from both co-occurring representatives of Dewalquea in having wider leaflets, and from D. aquisgranensis in lacking marginal serration (see Table 1).

To date, three entire-margined species of Dewalquea with more than three leaflets per leaf have been described: D. gelindenensis de Saporta and Marion, 1873 , from the Paleocene of Belgium, as well as D. reniformis Krassilov in Krassilov et al., 2005, and D. gerofitica ( Dobruskina, 1997) Krassilov in Krassilov et al., 2005 from the Turonian of Negev ( Krassilov et al. 2005). The former is relatively close to the material described herein in leaflet shape and venation; however, the Paleocene species has always slightly emarginate apices (de Saporta and Marion 1873: pl. 9: 1, 4, 5). This character is difficult to check in plants from Lower Silesia, but a single leaflet seems to show a straight apex; one cannot be certain, however, that this is not a preservational artefact. In all other leaflets apices are not preserved. The two Turonian species differ from the material described herein in terms of leaf organisation (high divergence angle of leaflets for the former, leaf composed of four, more seldom five leaflets for the latter). To sum up, the material described here might represent a new species, but is described under open nomenclature due to insufficient preservation.

Leaves from eastern Poland described as Debeya insignis by Halamski (2013: figs. 8, 9A, F), but differing in having entire margins (see above), may represent the same species, although their preservation is rather fragmentary.

Genus Dalbergites ( Velenovský, 1885) Halamski and Kvaček, 2015

Type: Dalbergites atavius ( Velenovský, 1885) Halamski and Kvaček, 2015 ≡ Cassia atavia Velenovský, 1885 ; Coniacian, Upper Cretaceous; Idzików, Kłodzko region, Poland.

Dalbergites sp.

Fig. 17F.

Material.—Rakowice Małe, Assemblage 5, upper Coniacian?–lower Santonian?: MB.Pb.2018/0068. Żerkow ice,Assemblage 5, upper Coniacian?–lower Santonian?: MB.Pb. 2018/0023.

Description.—Lamina incompletely preserved, ca. 20 mm longand13mmwide,mediallyasymmetrical.Baserounded? Apex not preserved. Venation pinnate, secondaries poorly

Fig. 12. Eudicot angiosperm Dewalquea aff. gelindenensis de Saporta and Marion, 1873 from Bolesławiec, North Sudetic Basin, Lower Silesia, Poland, → Assemblage 8 (lower–middle Santonian). A. Incomplete compound leaf MGUWr 2881p; general view (A 1), note a small fragmentary compound leaf of Dewalquea haldemiana in the bottom left corner; enlargement of the middle part a leaflet showing venation (A 2) and of the basal part with petiole and petiolules (A 3). B. Subcomplete compound leaf MGUWr 2880p (specimen figured by Roemer 1889: pl. 12: 3 as Debeya haldemiana ); general view (B 1), enlargement of the distal part of a leaflet (B 2; interpretation uncertain, apex or taphonomic bias); enlargement of the middle part of a leaflet showing venation (B 3) and of the basal part with petiole and petiolules (B 4). C. Fragmentary compound leaf MGUWr 6150p.

preserved, proximally decurrent, distally excurrent(?), departing at an angle of 50–80°. Margin unlobed, untoothed.

Remarks.—Small asymmetric phyllomes are interpreted as leaflets of pinnately compound leaves ( Halamski and Kvaček 2015).

Figures

Fig. 11. Taphonomy of the eudicot angiosperm Dewalquea insignis Hosius and von der Marck, 1880 from the North Sudetic Basin, Lower Silesia, Poland. A. Fragmentary compound leaf MB.Pb.2008/325.1, Bolesławiec, Assemblage 8 (Santonian); general view (A1) and enlargement of fragments of two leaflets to show venation and teeth (A2). B.Accumulation of leaflets (presumably from the same compound leaf) MGUWr 5639p accompanied by Salicites? sp. and unidentified vegetal remains, Ulina?, Assemblage 8? (Santonian?).