Source: https://sp.lyellcollection.org/content/434/1/207
Timestamp: 2019-04-23 08:28:08+00:00

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A Late Cretaceous (Campanian) leaf megaflora from the Vomb Trough in southern Skåne, Sweden, has been investigated on the basis of collections held at the Swedish Museum of Natural History. The main plant-bearing locality is Köpinge, but single specimens originate from Högestad, Ingelstorp, Rödmölla, Svenstorps mölla and Tosterup. The fossil flora is dominated by the angiosperm (eudicot) Debeya (Dewalquea) haldemiana (Debey ex de Saporta & Marion) Halamski. Other dicots are cf. Dryophyllum sp., Ettingshausenia sp., Rarytkinia? sp., Dicotylophyllum friesii (Nilsson) comb. nov. and Salicites wahlbergii (Nilsson) Hisinger. Conifers are represented by cf. Aachenia sp. (cone scales), Pagiophyllum sp. and Cyparissidium sp. (leaves). Single poorly preserved specimens of ferns and monocots have also been identified. The terrestrial palynomorphs (the focus herein) clearly link to the megaflora, although with different relative abundances. The fern spore Cyathidites dominates along with the conifer pollen Perinopollenites elatoides and Classopollis. Angiosperm pollen comprise up to 15% of the assemblage, represented by monocolpate, tricolpate and periporate pollen and the extinct Normapolles group. The spores in the kerogen residue show a thermal alteration index (TAI) of 2+.
The flora probably represents mainly a coastal lowland Debeya/conifer forest, and is similar to approximately coeval assemblages from analogous palaeo-communities described from eastern Poland, western Ukraine and Westphalia.
Late Cretaceous terrestrial to shallow-marine rocks of Skåne, southern Sweden yield plant micro-, meso- and megafossils. The micro- and mesoflora have been the subject of several studies over the past three decades (mostly from northern Skåne: see the review by Friis et al. (2011, pp. 70–72)). The wood remains and fossil cones were described by Conwentz (1892), Nykvist (1957), Srinivasan & Friis (1989) and Herendeen (1991). However, the leaf megaflora has only been reported and briefly described in a few publications from the first half of the nineteenth century (Nilsson 1824, 1832; Hisinger 1837), and no palynological analyses have been performed on the Campanian successions from the Vomb Trough. This paper aims to revise the Campanian leaf flora from the Vomb Trough in southern Skåne (Fig. 1) and to compare the megaflora to the palynological assemblage recovered from the same strata. Santonian leaves and cones from the Kristianstad Basin in northern Skåne will be dealt with in a separate study.
Geographical and geological setting of the studied flora. (a) Present-day geography of northern and central Europe compared to Campanian palaeogeography (after Ron Blakey, from Csiki-Sava et al. (2015), modified after data in Chatziemmanouil (1982), Surlyk in Voigt et al. (2008) and Halamski (2013)), and the presumed location of the studied flora and of three other coeval palaeofloras (circle, Poland–Ukraine; square, Haldem in Westphalia; triangle, Grünbach in Austria). (b) Bedrock geological map of Skåne (Scania) and adjacent regions after Koistinen et al. (2001), Vajda & Gravesen (2008) and references therein. (c) Solid geological map of the Vomb Trough in southern Skåne showing the localities that have yielded the fossil flora studied, after Christensen (1986).
Fossil plants from the Late Cretaceous deposits of Skåne were first mentioned and illustrated by Nilsson (1824). Sven Nilsson (1787–1883) began collecting objects of natural history in his youth, becoming Associate Professor in Natural History at Lund University by 1812. He took up the directorship of the Swedish Museum of Natural History in Stockholm (NRM) in 1828, but in 1832 he returned to Lund taking up a professorship in natural history until 1856. During his time at NRM, he assembled a collection that served as the basis for the first detailed study of Swedish Cretaceous plants, with the description of five new species from Köpinge (Nilsson 1832). Nilsson's palaeozoological collections were donated to the museum in Lund and have been used by subsequent researchers (e.g. Lundgren 1865, p. 1, 1874, p. 70, 1880, p. 23). Among the palaeobotanical collections available to the present authors, only two specimens (S084165 and Lund s.n. (s.n., sine numero)), however, can be attributed unambiguously to the Nilsson collection. Some of his plant fossils are, perhaps, present amongst a collection of material originating from Lund but now (2015) registered at the NRM, but the documents detailing the collector(s) and transfer are lacking. This concerns, in particular, type and figured specimens that could not be traced for the purpose of the present study. Nilsson's specific descriptions were repeated by Hisinger (1837), who moreover introduced four new genera based on these species. He later relisted the four dicotyledonous species from Köpinge in a synoptic table of fossils from Skåne (Hisinger 1840, p. 58).
Another major collection from the studied area (available to the present authors) was assembled by a collector named Gustaf von Schmalensée (1842–1919), and was deposited in the NRM during the years 1879, 1880 and 1903. It partly derives from the Swedish Geological Survey (Sveriges Geologiska Undersökning) collections, as testified by a letter of Edvard Erdmann to Alfred Gabriel Nathorst, a professor at the NRM, dated 5 November 1902. Nathorst (1881) had already published a short nomenclatural remark on the most abundant species at Köpinge and apparently planned to undertake a more extensive study of this flora, based on the names attributed to him occurring on collection labels. However, these names have never been published.
‘Dewalquea nilssonii’ was listed among fossils from Köpinge by Moberg (1884). The flora of ‘Köpinge Sandstone’ was then briefly mentioned by Hartz (1909, p. 2), who described it as consisting of: ‘fragmentary rests of ferns, conifers, and angiosperm trees; the most common leaf being that of Dewalquea Nilssonii (Helleboreæ?)’. A similarly laconic remark was made by Ross (1949, p. 38), who stated: ‘a few dubious dicotyledonous fossils [Acerites, Alnites, Cycadites (Dewalquea), Salicites] from the Upper Cretaceous of Scania’. Unlike the floras from the Kristianstad Basin, Cretaceous plants from southern Skåne have not been studied for more than a century.
Skåne (also known as Scania) is a province of southern Sweden that incorporates the geological transition (Sorgenfrei–Tornquist Zone) between the Baltic (Fennoscandian) Shield and the Danish Basin within the Northwest European Craton. Mesozoic strata are known in Skåne from both outcrops and borings. Cretaceous deposits are known from several areas (Fig. 1b), the most important from a palaeobotanical perspective being the Kristianstad Basin, situated on the southernmost part of the Fennoscandian Shield, and the Vomb Trough, situated in the Fennoscandian Border Zone (Christensen 1984; Larsson et al. 2000). The Late Cretaceous landscape of Skåne consisted of several elongate islands and peninsulas (Fig. 1a) formed of basement (Precambrian–Palaeozoic) rocks surrounded by shallow-marine areas (Surlyk in Voigt et al. 2008, p. 940). Åsen, a well-known fossil site within the Kristianstad Basin, hosts charcoalified flowers within Santonian–lower Campanian fluvial deposits (Skarby 1968; Friis 1984; Friis et al. 2011). Within the Kristianstad Basin, the fluvial successions are overlain by marine glauconitic calcareous sandstones hosting a rich fossil biota, including a range of invertebrates (Einarsson et al. 2016), but also vertebrates including sharks and fish (Bazzi et al. 2015; Siversson et al. 2015), mosasaurs, plesiosaurs (Einarsson et al. 2010) and even non-avian dinosaurians (Poropat et al. 2015). Oysters were described from Åsen showing heteromorphic ornamentation interpreted as attachment in vivo to arborescent plants (presumably mangroves: Friis & Skarby (1981)).
The Vomb Trough (Fig. 1c) is a graben extending for about 55 km northwestwards and 25 km southeastwards from Ystad (Norling 1982). It is bordered by the Precambrian Romeleåsen Horst to the SW and by a lower Palaeozoic plateau to the NE: both were also areas of elevation in the Cretaceous (Chatziemmanouil 1982) and, thus, may be assumed to be the source of the flora described from the localities situated in that region. The Upper Cretaceous stratigraphy of the Vomb Trough was elaborated by Christensen (1986) on the basis of belemnites.
The richest Late Cretaceous megafloral assemblage in Skåne derives from Köpinge. The name of this locality (also Köpinge mölla) situated approximately 10 km NE of Ystad (not to be confused with Köpinge 10 km SE from Kristianstad) denotes a large number of small outcrops (see detailed description by Hägg (1954, pp. 11–13): most of them described as already inaccessible by Christensen (1986)) of a yellow calcareous sandstone rich in glauconite, the so-called ‘Köpinge sandstone’. Besides plants, the ‘Köpinge sandstone’ has yielded foraminifera (Brotzen 1938), molluscs (Schlüter 1870), brachiopods (Dalman 1828; Hägg 1954) and vertebrates (Nilsson (1835): see the list published by Moberg (1884, p. 35) and the bibliography in Christensen (1986, p. 9)). The rock is sufficiently characteristic to also be recognized among erratic boulders (Foth et al. 2011). The age of the ‘Köpinge sandstone’ (Christensen 1986) is latest early Campanian and middle late Campanian (strata of earliest late Campanian age are apparently absent). The locality Svenstorp (or Svenstorps mölla) is situated in the greater Köpinge area (Hägg 1954, pp. 11–12). Ingelstorp is situated immediately SE of Köpinge and the sandstone exposed in this parish is about the same age as that from the latter locality (Hägg 1954, p. 15). Högestad is situated about 10 km NW of Köpinge and strata exposed there belong to the middle part of the Campanian (Mucronatenkreide sensu Hägg (1954, pp. 11, 15); see also Christensen (1976, pp. 16–17)).
The localities Rödmölla and Tosterup, situated approximately 2 km east of Köpinge, require a slightly more detailed comment. A series of outcrops formerly existing in that area exposed several Upper Cretaceous beds (Christensen 1976, pp. 11–12; see also Moberg 1884, pp. 31–34). Some of them belong to strata older than the succession at Köpinge (Mamillatenkreide sensu Hägg 1954, p. 4); however, it may be assumed that the plant material comes from the Tosterup conglomerate dated to the latest early Campanian on the basis of belemnites (Christensen 1976, p. 13).
The studied material consists of 160 specimens, 147 of them (92%) derived from Köpinge. The absolute and relative abundances of the various taxa identified in this collection are summarized in Table 1. Plant fossils were studied entirely from historical collections, as the outcrops are long since inaccessible. Most of the name-bearing specimens (types) of Nilsson (1832) could not be found and are probably lost. This is particularly unfortunate because taxonomic interpretations of the relevant taxa will necessarily be hypothetical. Taxa that could not be identified due to a lack of specimens are Acerites cretaceus (Nilsson, 1832) Hisinger, 1837, Comptonites antiquus (Nilsson, 1832) Hisinger, 1837 and Cannophyllites septentrionalis Nilsson, 1832. The studied collection of 159 specimens is housed in the NRM in Stockholm. A single specimen is housed in the type collection at the Department of Geology, Lund University, Sweden.
The plant fossils are fragmentary or incomplete leaves preserved as imprints in calcareous sandstone (Figs 2, 3, 4, 5, 6, 7) and many are curved (i.e. not preserved along a single plane): this suggests high-energy sedimentation or bioturbation. The leaves are distinguished from the surrounding rock owing to their brownish coloration (Fig. 2a, c–f), likely to be a result of bacterially mediated ferric-oxide precipitation. Such preservation is rather similar to that of the coeval flora from eastern Poland and western Ukraine (Halamski 2013). Rare specimens are blackish (Figs 2b & 5c), suggesting a different type of preservation, but this has not been investigated in detail. Concerning the venation, in all leaves belonging to Ettingshausenia sp. tertiaries and quaternaries are preserved, and in Debeya haldemiana, two specimens bear faint traces of tertiaries (Fig. 5h), whereas in all other leaves only the midvein and the secondaries can be observed. Overall, the preservational state of the megaflora may be described as rather poor. Uncoated specimens were photographed under oblique and most often polarized light, using a Canon 350D digital camera either with a Canon EFS 17–85 mm lens or, if required, with a Canon EF 100 mm macro lens.
Taphonomy of the studied flora: (a) Rarytkinia? sp. co-occurring with a fragmentary leaf of Debeya (Dewalquea) haldemiana, specimen S085093, Köpinge; (b) three twigs of the conifer Pagiophyllum sp., specimen S083932, Köpinge; (c) the terrestrial angiosperm Salicites wahlbergii S084155 (neotype) co-occurring with a marine bivalve, Köpinge; (d) Pagiophyllum sp., a conifer twig, Lund s.n. (original of Nilsson 1832, pl. 2, fig. 7), Köpinge; (e) cf. Aachenia sp., a conifer cone scale, specimen S084113, Köpinge; (f) subcomplete compound leaf S166107 of Debeya (Dewalquea) haldemiana; and (g) fragmentary leaflets of Debeya (Dewalquea) haldemiana, the arrangement of which suggests that they come from a single compound leaf, specimen S084187, Köpinge.
(a) Ferns and (b)–(g) conifers from the studied flora. (a) Korallipteris sp., fragmentary twig S084170, Köpinge. (b)–(g) Pagiophyllum sp.: (b) twigs S083936, Köpinge; (c) twig S084212, Rödmölla; (d) twig S166168, Köpinge; (e) twig S166108, Köpinge; (f) twig S083929, Köpinge; (g) twig S166150 cut transversely, Köpinge.
Conifer Cyparissidium sp. Twig S084219, Svenstorps mölla.
Eudicot Debeya (Dewalquea) haldemiana (all figured specimens from Köpinge), the most common plant in the studied flora: (a) leaf fragment S084189, showing incomplete petiole and seven incomplete petiolules in pedate arrangement; (b) S084032, one of the largest leaflets in the material studied; (c) apical parts of two leaflets, specimen S084201; (d) incomplete compound leaf S083957, with a complete petiole and basal parts of five leaflets; (e) & (f) fragmentary compound leaves, S083948 and S083947; (g) accumulation of probably juvenile leaflets, specimen S084188; and (h) leaflet S084058, with preserved secondary brochidodromous venation.
(a) Monocots and (b)–(f) platanoid Ettinghsausenia sp. from the studied flora: (a) Monocotyledoneae ord., fam., gen. et sp. indet., leaf fragment S084048, Köpinge; (b) leaf fragment S166202 showing venation, Tosterup; (c) leaf fragment S084207 showing the margin, Rödmölla; (d) incomplete leaf S166203, Tosterup; and (e) leaf fragment S166204, Högestad.
Dicots from the Campanian of Köpinge: (a) Dicotylophyllum friesii, leaf fragment S083980 showing margin; (b), (c) & (e) Dicotylophyllum friesii, leaf S084030 (neotype), general view and enlargements of the margin and of the decurrent departure of secondaries; (d) & (f) cf. Dryophyllum sp., incomplete leaf S084140, apical part and general view; (g) Rarytkinia? sp., incomplete leaf S083990.
Two rock samples from the Köpinge locality (NRM-S089754 and NRM-S089755), each yielding leaf macrofossils, were selected for palynological analysis. Around 10 g of beige, fine-grained sandstone were processed according to standard palynological procedures at Global Geolab Ltd, Canada (e.g. see Vajda et al. 2013). The organic residue was sieved using a 5 µm mesh and mounted in epoxy resin on two microscopic slides. Three hundred pollen and spores were identified per sample and the percentage of each palynomorph taxon was calculated (Table 2) In addition, one kerogen slide was prepared from each sample (i.e. where the residue did not go through the oxidation or sieving processes) in order to estimate the thermal alteration index (TAI) of the palynomorphs.
Palynofacies analysis involved counting the relative abundance of organic particles based on 500 counts per slide. Classification of the palynological matter was based on the scheme developed by Batten (1996), and the groups identified were: (I) palynomorphs (pollen, spores, dinoflagellates and algae); (II) wood; (III) charcoal; (IV) plant cuticle; and (V) amorphous organic matter (AOM). The slides and residues are deposited in the palaeobiology collections of the NRM, Stockholm, and light micrographs of selected pollen and spores from the two studied samples are illustrated in Figure 8 and are identified by NRM numbers and England-finder coordinates.
Selected pollen and spores from samples SO89754 and SO89755 from the early Campanian Köpinge mölla locality. Specimens listed as: taxa, sample number and slide number, and England Finder Reference (EFR), scale bars are 10 µm. (a) Cingutriletes scanicus, NRM S089755-1, EFR-V32. (b) Gleicheniidites senonicus, NRM S089754-1, EFR-U28. (c) Cyathidites australis, NRM S089755-1, EFR-S32. (d) Pilosisporites sp., NRM S089754-1, EFR-T13. (e) Vitreisporites bjuvensis, NRM S089755-1, EFR-V34. (f) Chasmatosporites apertus, NRM S089755-2, EFR-S30. (g) Perinopollenites elatoides, NRM S089754-2, EFR-U32. (h) Araucariacites australis, NRM S089755-1, EFR-R33. (i) Alisporites thomasii, NRM S089754-2, EFR-O23. (j) Normapolles: Trudopollis sp. NRM S089754-2, EFR-V34. (k) Normapolles: Trudopollis variabilis, NRM S089755-1, EFR-X47. (l) Comptoniapollenites sp. NRM S089755-2, EFR-R32. (m) Tricolpites reticulatus NRM S089755-2, EFR-V36. (n) Tricolplites reticulatus NRM S089755-1, EFR-V34. (o) Normapolles: Extremipollis caminus NRM S089754-1, EFR-T28. (p) Normapolles: Extremipollis caminus (undeveloped), NRM S089754-1, EFR-U28. (q) Normapolles: Trudopollis sp. NRM 23-1, J32. (r:1) Platanuspollenites. (r:2) NRM S089754-1, EFR-T38.
Type species. Korallipteris argentinica (Berry) Vera & Passalia (2012, p. 423, figs 1A–D, 2)≡Gleichenia argentinica Berry (1924, p. 18, pl. 1, figs 1–5). Meseta Baqueró, Santa Cruz Province, Argentina; Baqueró Group (Aptian).
Description. The single available specimen is a frond fragment approximately 25 mm long. The pinnules are 2–2.5 mm long and of about the same width, alternate to subopposite, pecopteroid, integrimarginate, with a main vein perpendicular to the rachis and a few secondary veins branching at high angles therefrom.
Remarks. Fern frond fragments reported herein under Korallipteris are very similar (although not identical) to those reported as Microphyllopteris by Halamski (2013).
Type species. Aachenia debeyi Knobloch (1972, p. 401, figs 1–10). Aachen, Germany; lower Campanian.
Description. Ovuliferous cone scale 14 mm long and 12 mm wide, triangular in outline, with an attenuate apex and an inconspicuous keel. The basal region of the scale bears three impressed depressions probably representing seeds attached at the base of the scale. The seeds are ovoid, 4–5 mm long and 2–3 mm wide. It is unclear whether the lack of a basal stalk characteristic of Aachenia is a preservation artefact or if the stalk was originally missing.
Remarks. This ovuliferous scale is broadly similar to scales described as Aachenia debeyi from the Late Cretaceous of Aachen (Knobloch 1972) and A. knoblochii Wagner from the Maastrichtian of Mexico (Weber 1985). However, a basal stalk diagnostic of Aachenia is missing in the studied specimens: hence, the material is reported under open nomenclature.
Type species. Pagiophyllum circinicum Heer (1881, p. 11, pl. 10, fig. 6); Portugal; Upper Jurassic.
1832 fructification af en Cycadit – Nilsson: 8; pl. 2, figs 4–7.
Material. Köpinge: S083923, 083925–083929, 083931, 083932–083936, 084122, 084169, 084173–084177, 084203, 084204, 084217, 084222 (cast), 085088, 085089, 085102, 166108–166111, 166113, 166150, 166151, 166168, Lund s.n. (original to Nilsson 1832, pl. 2, fig. 7). Rödmölla: S084212.
Description. Fragments of isolated branches with helically arranged leaves. Leaves obovate, typically 0.5–2×1–5 mm. A perpendicularly broken specimen (Fig. 3g) has a quite flat obovate lamina without a pronounced keel. Branch diameter ranges from 7 mm (S84217) to 12 mm (S84212).
Remarks. Leaves are longer than wide, a characteristic feature of Pagiophyllum as reintroduced by Harris (1969). There are numerous similar fragmentary sterile branches described from several Cretaceous deposits globally (e.g. from the Campanian of Grünbach: Herman & Kvaček (2010); Campanian of James Ross Island, Antarctica: Kvaček & Sakala (2012), Kvaček & Vodrážka (2016)). The studied material has leaves similar in shape to Brachyphyllum patens (Miquel, 1853) (van der Ham & van Konijnenburg-van Cittert in van der Ham et al. 2003), and Brachyphyllum sp. 1 and sp. 2 (van der Ham & van Konijnenburg-van Cittert in van der Ham et al. 2003) from the Maastrichtian of The Netherlands and Belgium.
Type species. Widdringtonites gracilis Heer, 1868; West Greenland; Cretaceous (Heer 1868, p. 83).
Remarks. We employ this genus in the sense of its emendation by Harris (1969, pp. 248–249; see also Harris 1979, p. 77).
Description. The single available specimen represents a fragment of a leafy twig 23 mm long with numerous, dense, helically arranged, needle-like leaves. The leaves are 0.7×3 mm and appressed to the axis, forming a branch 3 mm in diameter.
Discussion. The studied material is similar to Cyparissidium bohemicum Bayer and Cyparissidium minimum Vel. from the Cenomanian of the Bohemian Cretaceous Basin (Velenovský 1885; Bayer 1914, 1920; Kvaček 1999). It is particularly similar to C. minimum based on its very delicate needles. However, both mentioned species have epidermal features preserved, so these names are inappropriate for the Skåne specimen.
Type species. Dewalquea haldemiana Debey ex de Saporta & Marion, 1873; Late Cretaceous, Haldem, Westphalia.
1824 en bladform – Nilsson: 147; pl. 2, figs 4, 6.
non 1825 Cycadites nilsoni Sternberg: XXXII; pl. 47, fig. 1.
1873 Dewalquea haldemiana (Araliophyllum haldemianum Deb. Ms.) – de Saporta & Marion: 60–61; pl. 7, 1–2.
v* 1880 Dewalquea haldemiana Sap. & Mar. var. latifolia; Hosius & von der Marck 1880: 173; pls 35: 114, 34: 115.
v. 1880 Dewalquea haldemiana Sap. & Mar. var. angustifolia; Hosius & von der Marck 1880: 173; pls 33: 116–117, 34: 118–121.
? 1883 Dewalquea haldemiana Sap. et Mar. – Heer: 37; pl. 55, figs 19a, 20; pl. 62, figs 2–4.
1884 Dewalquea Nilssoni – Moberg: 35.
v. 1907 Dewalquea haldemiana Sap. et Mar.; Nowak 1907: 53; pl. 1, figs 7, 13.
v. 2013 Debeya haldemiana (Debey ex de Saporta & Marion, 1873) Knobloch, 1964 – Halamski: 422, figs 7B, G, 8, 9C, D, E, 10C.
v. 2013 Debeya (Dewalquea) haldemiana (Debey ex de Saporta & Marion, 1873) Halamski 2013 – Halamski & Kvaček: 83, text-fig. 1.
Material. Köpinge: S083947, 083948, 083957–083963, 083968–083971, 083975–083979, 084005, 084016, 084018, 084021–084027, 084031–084033, 084035, 084040, 084041, 084058, 084077, 084078, 084091, 084099, 0840101, 0840103, 0840115, 0840117, 0840123, 0840124, 0840126, 0840127, 0840129, 0840138, 0840139, 0840142, 0840143, 0840150, 0840151, 0840158, 084165, 084187–084195, 0840197–0840202, 0840205, 085090, 085091, 085098, 166107, 166297, 16123, 166124, 166126, 166128, 166114, 166116, 166121–166122, 166127, 166129, 166131, 166134–166136, 166139, 166140, 166142–166144, 166147, 166155–166158, 166163–166164, 166179, 166180, 166182.
Description. Leaves pedately compound, with presumably from five to nine leaflets. Petiole 20–25 mm long, relatively slender, weakly enlarged proximally. Leaflets subsessile, linear, usually 4–10 mm wide (maximum recorded width 16 mm), total length unknown (exceeding 9 cm in a leaflet 4 mm wide). Base cuneate, apex not preserved. Margin entire. Midvein straight, strong; secondaries generally not preserved, brochidodromous, subopposite, excurrent; tertiaries observed in two specimens (Fig. 5h), leaving the proximal side of secondaries at a right angle.
Remarks. Debeya haldemiana is by far the most common plant species in the material studied. The specimens are usually leaflets showing no organic connection, only rarely do they represent incomplete leaves (apical parts always lacking). In comparison to other localities from which this species was reported (Haldem, Potylicz), the striking feature of the Köpinge material is the common occurrence of small leaves (up to 4 mm in width compared with presumably adult leaves 10 mm or more wide).
Debeya from Köpinge was first mentioned and illustrated (without formal description) by Nilsson (1824). The name Cycadites Nilsoni was first published by Sternberg (1825, in 1820–38, p. XXXII; pl. 47, fig. 1) for a Late Triassic or Early Jurassic cycadophyte (holotype: S087452; correct name: Nilssonia brevis Brongn.; Brongniart (1824, p. 218); Sternberg's name is thus a nomen illegitimum, Kvaček & Straková (1997, p. 109)). The same name (spelt Cycadites Nilsonii) was then published by Brongniart (1828, p. 204) in a synoptic table of Cretaceous plants from various localities. An indication of the locality and the collector was given, but neither diagnosis nor description: it might be a matter of contention as to whether such a reference to a previous illustration is sufficient for this name to be valid, had it not been preoccupied by Sternberg's illegitimate name (Brongniart's name is, in any case, a homonym). The diagnosis and figure of the Cretaceous angiosperm described as Cycadites Nilssonii was first published by Nilsson (1832), with authorship credited to Brongniart. The conclusion about the identity between Cycadites nilssonii and Dewalquea haldemiana was presented by Nathorst (1881, pp. 83–84), who also introduced the combination Dewalquea nilssonii (Nathorst, 1881, p. 84). Heer cited Nathorst's paper in an appendix to the second part of his Greenland flora monograph (Heer 1883, p. 274): in the main text, he used the name D. haldemiana (at least a large part of his material from Greenland being not conspecific with the plant from Köpinge and Haldem). In the index to the aforementioned work, Heer (1883, p. 268) made a lapsus calami, misspelling the name as D. nielssenii. This error was repeated by van der Burgh (2008, p. 12), who moreover misattributed the authorship of the combination Dewalquea nilssonii to Heer. The name Dewalquea nilssoni was mentioned by Lundgren (1885, p. 84). In summary, the name Cycadites nilssonii Brongn. was preoccupied by Cycadites nilssonii Sternb. and thus is illegitimate, so the correct name for the discussed taxon is Debeya (Dewalquea) haldemiana.
Type species. Dryophyllum subcretaceum Debey ex de Saporta, 1865. Sézanne, France; Eocene.
Material. S084140, 085096 (part and counterpart).
Description. The single available specimen is an incomplete leaf (basal region lacking; preserved length c. 7 cm). Leaf size microphyll (estimated total length c. 10 cm, estimated total width c. 4 cm, thus a length to width ratio of c. 2.5), shape elliptical. Base not preserved, apex acute. Margin serrate, teeth regular, 2–3 per cm. Venation pattern pinnate; secondaries craspedodromous, spaced at approximately 5–9 mm, spacing irregular and asymmetric, departure angle 30°–60°.
Remarks. This specimen is compared to Dryophyllum (as emended by Halamski & Kvaček 2015) on account of its elliptical shape, pinnate craspedodromous venation and asymmetry of the secondaries, suggesting that it is, in fact, a leaflet of a pinnately compound leaf. However, interpretation of the single poorly preserved specimen is equivocal at best.
Type species. Credneria cuneifolia Bronn, 1835–37; Upper Cretaceous, Cenomanian, Niederschöna, Saxony, Germany.
Rödmölla: S084206, 084207, 084210, 084211.
Description. Leaves entire-margined or with few teeth, trilobate with lobes poorly developed. The fragments vary in size, the smallest being 40×20 mm and the largest over 50 mm wide, suggesting that complete leaves were relatively small (c. 7 cm in width and length). Leaf lamina obovate. Apex acute (Fig. 6e); base probably cuneate as fragmentarily preserved (Fig. 6c). Lobes very small (Fig. 6e) or nearly absent (specimen S084207). Petiole preserved in a single specimen (Fig. 6d).
Venation palmately pinnate semibrochidodromous. Midvein stout, terminating in the leaf apex. Two pairs of suprabasal secondary veins emerging obliquely from the midvein. No infrabasal secondary vein. Secondaries semibrochidodromous (Fig. 6e). Tertiary veins prominent, straight or slightly curved, percurrent.
Remarks. The studied material is very similar in general venation style and size to Ettingshausenia gruenbachiana Herman & Kvaček, 2010 from the lower Campanian of Grünbach. It differs in its more angular leaf form and less pronounced lobes. The studied material differs from Ettingshausenia? lublinensis (Karczmarz & Popiel, 1971) Halamski, 2013 from the late Campanian of Poland in having an entire-margined lamina without any strongly pronounced lobes. Ettingshausenia sp. differs from Ettingshausenia onomasta (Bayer, 1896) Kvaček & Halamski in Halamski & Kvaček 2015 from the Coniacian of Idzików in having more pronounced tertiary venation and less pronounced lobes.
Type species. Rarytkinia terechovae Vassilevskaya & Golovneva in Golovneva & Abramova 1990; Rarytkin Formation, upper Maastrichtian–Danian, Koryak Upland, NE Russia.
Material. Köpinge: S083988, 083990, 085092–085093 (part and counterpart), 085099.
Description. Blade attachment marginal, laminar size mesophyll (two fragmentary specimens are 10 cm long, the estimated total length is thus about 15 cm), estimated laminar length to width ratio of approximately 2.5, laminar shape unknown, possibly either elliptical or ovate. Base and apex unknown. Primary venation pinnate, possibly craspedodromous. In the basal region, a secondary vein departing at 65° is evident; more distally, secondaries depart at 45°–55°, excurrent. Spacing of secondaries irregular, 1–2 cm between successive veins; intersecondaries absent. Margin not preserved.
Remarks. This leaf is tentatively ascribed to Rarytkinia on the basis of its large size and the departure angle of the secondary veins being significantly high in the basal region, but low and constant in the rest of the leaf. A coeval representative of the genus is the insufficiently known Rarytkinia polonica (Karczmarz & Popiel) Halamski from eastern Poland (Halamski 2013), which differs from the form described here in its wider shape and denser secondaries. Some leaves in the collection are labelled ‘Protophyllum suecicum Nath. mscr.’, but this name has never been published and, thus, has no nomenclatural status; the available material is insufficient for a formal description.
Type species. Unknown (see Halamski 2013, pp. 429–430).
Remarks. Alnites Hisinger is a synonym of Alnites Goeppert (1836, p. 564, pl. 41, figs 1–7 – type Alnites kefersteinii Goeppert), which is recognized as a member of the genus Alnus – Alnus kefersteinii (Mai & Walther, 1978) and thus seems inappropriate for our material. Alnites Deane (1902) from the Tertiary of Australia is another synonym. The most appropriate genus to accommodate these Skåne leaves appears to be Dicotylophyllum, based on their few generalized characters.
Dicotylophyllum friesii (Nilsson, 1832) comb. nov.
*1832 Phyllites (Alnus? Friesii) – Nilsson: 346; pl. 1, figs 7.
Neotype. S084030 from Köpinge (selected herein).
Basionym. Phyllites friesii Nilsson, 1832, p. 346, pl. 1, figs 7.
Description. The available material consists of leaf fragments, one representing the basal and median regions of the lamina, and the other the apical region: the base and apex themselves, however, were not preserved. Leaf elliptical, estimated length of approximately 8–10 cm, estimated width approximately 2 cm. Midvein straight. Secondary veins partly decurrent and partly excurrent (Fig. 7e), alternate, angle decreasing from c. 60° in the basal region through to c. 40° in the middle of the lamina to c. 30° in the apical region; spacing irregular. Margin serrate with one order of teeth and three teeth per cm; teeth short, proximal side convex, distal side weakly concave.
Remarks. In the absence of the holotype, the interpretation of the simple description and somewhat schematic figure given by Nilsson (1832) is not easy. However, the finely serrate (‘subcrenatus’) margin and the elliptical shape make the conspecificity of the material described here with Nilsson's species probable. A neotype is selected to fix the usage of the species name.
Type species. Phyllites wahlbergii Nilss.; Köpinge, Skåne; Campanian.
Emended diagnosis. See Halamski & Kvaček (2015).
*1832 Phyllites (Salix? Wahlbergii) – Nilsson: 345; pl. 1, figs 5, 6.
Neotype. S084155 from Köpinge (selected herein).
Material. Köpinge: S084000, 084001, 084011, 084185.
Description. Blade attachment marginal, leaf petiolate. Laminar size microphyll (maximum preserved length c. 60 mm). Laminar shape elliptical, asymmetrical. Base and apex weakly convex. Margin entire. Venation pattern pinnate, midvein straight; secondaries weak brochidodromous, excurrent, spacing slightly irregular, departure angle 40–60°; higher-order venation not preserved.
Remarks. Again, the interpretation of Nilsson's species in the absence of types is not easy. However, the absence of teeth and the irregular spacing of secondary veins is consistent with the figure in the protologue.
Monocotyledoneae ord., fam., gen. et sp. indet.
Material. Köpinge: S084048, 084051 (part and counterpart).
Description. The single available specimen consists of two leaf fragments on a single rock sample, one fragment is approximately 17 mm long and 5.5 mm wide, and the other is approximately 15 mm long and 8 mm wide. The margins of the smaller fragment run parallel to each other; four parallel veins are present in the specimen. The larger fragment preserves only one margin and six parallel veins.
Remarks. The parallel venation allows a reasonably secure placement within monocots; no more detailed systematic analysis is possible given the fragmentary state of the specimen. Parallel veins without any forking distinguishes it from most cycad or bennettite foliage, which have forked veins.
Well-preserved palynological assemblages were recovered from two samples: 47 miospore taxa were recorded, of which 18 taxa constitute spores, 18 gymnosperm pollen and 11 angiosperm pollen. In addition, the freshwater alga Botryococcus occurs in both samples. Most taxa in these samples are long ranging with a mix of typical Jurassic holdovers, such as representatives of Cyathidites, Classopollis, Perinopollenites, Araucariacites and Alisporites, together with typical Late Cretaceous angiosperm pollen. The relatively high abundance of tricolpate and periporate angiosperm pollen (up to 15%) including Normapolles and Alnipollenites sp. (Table 2) suggests an age not older than Campanian and not younger than Maastrichtian, which is consistent with previous age determinations.
Sample NRM S089754 derives from the Köpinge locality and consists of fine-grained calcareous sandstone, and the organic residue yielded 32 species of pollen and spores (Table 2). The 11 spore taxa constitute 32% of the assemblage, the 15 gymnosperm pollen taxa represent 46% and the nine angiosperm pollen taxa embody 15%. In addition, the freshwater alga Botryococcus reaches 7% abundance. The spore component is highly dominated by the trilete fern spore Cyathidites (23%). Individual bryophyte and lycophyte taxa do not reach 1%. The gymnospermous component is represented by two important genera, Perinopollenites elatoides (9%) and Classopollis sp. (7%), but several other taxa reach significant levels (3–4% or above) (e.g. Cedripites, Sciadopitys, Pinuspollenites, Araucariacites and Alisporites) (Table 3).
The microscopic organic matter in this sample is dominated (56%) by non-marine palynomorphs and phytoclasts (pollen, spores, wood remains, leaf cuticle and Botryococcus): the rest is represented by dinoflagellates (17%) and AOM (27%: Table 3). No charcoal was identified. The kerogen sample indicates a thermal alteration index (TAI) of 2+, equivalent to 5 on the spore colour index (SCI) chart.
Sample NRM S089755 consists of fine-grained sandstone to siltstone. It yielded 33 pollen and spore taxa (Table 2). The spores are represented by 13 taxa and constitute 46% of the assemblage, gymnosperm pollen grains are represented by 15 taxa and attain 37%, and angiosperm pollen (c. 12%) are represented by seven taxa.
As in the previous sample, the spore assemblage is strongly dominated by Cyathidites (31%), followed by Deltoidospora and Gleicheniidites senonicus (Table 2). In this sample, lycophyte spores reach over 4% and are represented mainly by Retitriletes. The relative abundance of the various gymnosperm taxa is more evenly distributed in this sample compared to NRM S089754, and Perinopollenites elatodies dominates with 10%, followed by unidentified bisaccate pollen grains, Classopollis, Alisporites and Araucariacites: all reach relative abundances of about 3%.
The organic matter in this sample is also dominated by non-marine palynomorphs, but at the significantly higher relative abundance of 80%. Dinoflagellates reach only 4% in this sample, and AOM typical of marine environments reaches only 16% (Table 3). The kerogen sample indicates a TAI of 2+, equivalent to 5 on the SCI chart.
The Köpinge flora was unequivocally preserved in a near-shore marine environment, as evidenced by the significant dinoflagellate component in the palynological assemblages and the co-occurrence of abundant marine invertebrates together with the leaf fossils (Fig. 2c). Despite the evidently allochthonous character of the described fossil flora, analogies to better-preserved fossil assemblages allow some general remarks on the Skåne Campanian plant communities. The angiosperm Debeya haldemiana dominates the macroflora in the available collection (Table 1). The apparent dominance of Debeya haldemiana may be biased by the fact that even small fragments of these distinctive leaves may be identified, whereas scraps of other angiosperm leaves cannot. However, even if the true percentage of fossils belonging to this species is perhaps lower, its dominance in the studied assemblage is undeniable. The abundance of Debeya haldemiana in marine sandstones at Köpinge suggests that this species dominated a coastal lowland forest similar to those described from the Cenomanian of Crimea and the Late Cretaceous ‘Senonian’ of Sakhalin by Krassilov (1979, 1984; Debeyo-Dryophylletum sensu Krassilov, 1997).
Within the palynoflora, however, the gymnosperm pollen grains and the fern spores dominate, which is to be expected as these are wind dispersed and have a much higher spore/pollen production compared to angiosperms, which commonly are insect pollinated. The angiosperm pollen is well represented in the palynoflora, but Debeya pollen is unknown, so no palynomorph can be linked to these megafossils. The fern component is visible in both the spore and the megafloral record.
The local abundance of Perinopollenites elatoides (pollen assigned to Cupressaceae) and Classopollis (pollen attributed to Cheirolepidiaceae) does not show an obvious link to the local megaflora. Although Perinopollenites might be affiliated with the relatively abundant Pagiophyllum, the producers of the Classopollis grains are uncertain. Classopollis derives from cheirolepidiacean conifers, particularly Frenelopsis, which typically occurs in Late Cretaceous marine-influenced habitats (Uličný et al. 1997). This type of conifer is characteristic of Late Cretaceous halophytic habitats (Uličný et al. 1997; Kvaček 2000). However, megafossils of Frenelopsis were not recorded in the Swedish assemblages. This could be due to their lower fossilization potential compared, for example, to Pagiophyllum (cf. Riera et al. 2010). Alternatively, Classopollis might be affiliated with non-frenelopsid cheirolepids, which could conceivably include some species of Pagiophyllum or similar awl-shaped coniferous foliage (e.g. Otwayia Pole, 2000) based on foliar anatomical characters and associated pollen from both the northern and southern hemispheres (Pole 2000; van der Ham et al. 2003; Tosolini et al. 2015).
By contrast, Ettingshausenia sp., known from a single leaf fragment at the richest locality of Köpinge and from more numerous specimens at Rödmölla and Tosterup (localities closer to the Palaeozoic plateau (Fig. 1c) and, arguably, to the Cretaceous shoreline), is best interpreted as a tree of riparian forests, as generally interpreted for platanoids (Doyle & Hickey 1976; Upchurch et al. 1994; Wing & Boucher 1998; Wing 2000; Coiffard et al. 2006).
It is problematic to link the angiosperm pollen taxa to the megaflora from the Köpinge site and currently we can only speculate. Monocolpate, reticulate Liliacidites pollen (monocotyledonous) is present in the palynoflora, but more abundant are representatives of the Normapolles Group, which make up 12–14% of the miospore assemblages yet are only represented by four taxa. Normapolles is a very diverse group with over 100 described species that had their greatest diversity during the Santonian and Campanian within the northern hemisphere (Skarby 1968; Friis et al. 2006, 2011), but were affected by the Cretaceous–Palaeogene mass extinction event, during which the group lost its diversity (Vajda & Bercovici 2014). The only extant plant-producing Normapolles-like pollen is Rhoiptelea (Friis et al. 2011) within Rhoipteleaceae, Fagales – an order that is represented within the megaflora at Köpinge.
The Campanian flora of southern Skåne may be compared with three approximately coeval floras: from eastern Poland and western Ukraine (mainly late Campanian: Halamski 2013); from Grünbach in Austria (early Campanian: Kvaček & Herman 2004; Herman & Kvaček 2010); and from Haldem in Westphalia (Hosius & von der Marck 1880), even if only the first two have been revised recently. Debeya haldemiana is a species shared between the floras of Skåne and Poland–Ukraine (although it is not so abundant in the latter regions). Other shared genera (but probably represented by different species) include Ettingshausenia, and probably also Rarytkinia and Korallipteris. Debeya haldemiana is also shared with the Haldem flora (see Halamski & Kvaček 2013), whereas cf. Dryophyllum sp. from Skåne is quite similar to the leaves reported by Hosius & von der Marck (1880) as species of Quercus. It is also notable that Ettingshausenia and probably Korallipteris occur at Haldem (Hosius & von der Marck 1880, pls 38–39, 42, fig. 176ff). Distinct similarities between these three floras (Skåne, Poland-Ukraine and Westphalia) reflect analogous palaeoecological settings within the same palaeoclimatic (palaeovegetation) zone. By contrast, the flora described herein is very different from that at Grünbach, which constitutes a thermophilic assemblage from a wet environment.
A comparison between the studied flora and an older (Coniacian) assemblage from the Sudetes (localities Idzików/Kieslingswalde and Nowy Waliszów/Neuwaltersdorf: Halamski & Kvaček 2015; Kvaček et al. 2015) shows that Korallipteris (earlier described as Microphyllopteris), Debeya, Ettingshausenia, Dryophyllum and Salicites are common to both floras, possibly reflecting similar palaeoecological conditions. Ettingshausenia is characteristic of Late Cretaceous floodplain vegetation (Kvaček & Herman 2004; Greguš & Kvaček 2015). The abundance of conifers in the Köpinge assemblage favours a source from a floodplain swamp vegetation. The occurrence of Classopollis pollen reflects a contribution from halophytic vegetation in the region, although macrofossil elements of this community are not obviously represented in the Skåne megaflora.
Palaeoclimatic inferences based on six dicotyledonous angiosperm taxa can be only very general. However, the approximately equal abundance of entire-margined and serrate/dentate taxa in the studied flora (3:3 if Ettingshausenia sp. is counted as entire-margined and 2:4 if it has a dentate margin) suggests an intermediate character of the vegetation between thermophilic and polar floras. This aspect is consistent with the coeval assemblages from Poland and Ukraine (Halamski 2013, p. 435). The palaeovegetation of a broad transitional zone situated in the European archipelago between approximate palaeolatitudes of 40–45° N (Poland) and 45–50° N (Skåne) thus seems to have been relatively uniform.
Campanian marine calcareous sandstones from the Vomb Trough in southern Skåne (main locality: Köpinge) yielded a relatively low-diversity vascular flora with one fern, three conifer species (one cone scale and two foliage taxa), six dicotyledonous angiosperms and one monocot angiosperm.
A well-preserved miospore assemblage was recovered from the same sediments as the megaflora, and 47 pollen and spore species were identified. In terms of abundance, the palynoflora is dominated by Cyathidites spores and gymnosperm pollen related to taxodiaceous Cupressaceae. Furthermore, angiosperm pollen is of relatively high diversity and, in terms of abundance, is mainly represented by pollen belonging to the Normapolles complex.
The megafossil assemblage is quantitatively dominated by the angiosperm Debeya (Dewalquea) haldemiana (Deb. ex Sap. & Marion) Halamski [=D. nilssonii (Brongn. ex Nilsson) Nath. non Sternberg, 1824], which constitutes up to 90% of the specimens. The conifer Pagiophyllum sp. is also a relatively abundant element of the flora.
Neotypes of Dicotylophyllum friesii (Nilsson, 1832) comb. nov. and Salicites wahlbergii (Nilsson, 1832) Hisinger, 1837 are selected.
The palaeoenvironment is interpreted on the basis of the mega- and palynoflora to represent a nearshore, possibly lagoonal, setting. This is more specifically corroborated by the relatively high abundance of dinoflagellates, together with the freshwater to brackish-water alga Botryococcus (which favours calm environments). The angiosperm Debeya haldemiana is interpreted as having formed coastal lowland forests.
The described flora is broadly similar to the approximately coeval assemblages from analogous palaeocommunities described from eastern Poland and western Ukraine (Halamski 2013) and Westphalia (Hosius & von der Marck 1880).
This study would have never been completed without the help of several colleagues in Stockholm and Lund who arranged the stay of ATH and JK at the NRM and Lund University, traced unregistered collections, provided data on the topography and stratigraphy of Skåne, translated texts from Swedish, and offered various other help; these are: Thomas Denk, Mats Eriksson, Kent Larsson, Anders Lindskog and Steve McLoughlin. The stay of ATH in Stockholm was financed by the European Union's Seventh Framework Programme (FP7/2007–2013) under grant agreement no. 226506 (SYNTHESYS). The project was also financially supported by the Ministry of Culture of the Czech Republic (DKRVO 2016/05, National Museum, 00023272) to JK and by the Swedish Research Council, through Lund University Carbon Cycle Centre (LUCCI). The two anonymous referees are thanked for their constructive criticism and valuable input to this manuscript.
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