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Ecology of some Late Triassic to Early Cretaceous ferns in Eurasia
Review of Palaeobotany and Palynology 119 (2002) 113^124 www.elsevier.com/locate/revpalbo
Ecology of some Late Triassic to Early Cretaceous ferns in Eurasia J.H.A. Van Konijnenburg-Van Cittert Laboratory of Palaeobotany and Palynology, University of Utrecht, Budapestlaan 4, 3584 CD Utrecht, The Netherlands
Abstract During the Late Triassic to Early Cretaceous the majority of ferns in Eurasia grew under warm (subtropical to tropical) conditions in moist environments, including peat-forming swamps, freshwater marshes, riverbanks and understorey vegetation in forests. Most of these ferns are assigned to families Marattiaceae, Osmundaceae, Schizaeaceae, Dicksoniaceae and Cyatheaceae. However, some ferns grew under much drier conditions or otherwise stress-related circumstances especially during the Jurassic and Early Cretaceous either as pioneer plants in coastal areas, on mountain slopes or on heathland. These include the Matoniaceae and Gleicheniaceae and to a lesser extent also the Dipteridaceae. Some species have so far been mainly or only recorded as fusain, indicating not only that wildfires occurred frequently at that time but also that ferns grew in such environments. Some specific taxa may have grown under different environmental circumstances in different, or even the same, periods. . 2002 Elsevier Science B.V. All rights reserved. Keywords: ecology; ferns; Late Triassic^Early Cretaceous; Eurasia
1. Introduction 1.1. Mesozoic environments and concepts of fern ecology The Mesozoic was an era of warm climate. Absence of polar icecaps and probably even belts of cold climate is indicated by ¢nds of thermophilic plant remains in the Arctic and Antarctic (Vakhrameev, 1991). After the recovery during the Early Triassic from the dramatic climatic changes and mass extinctions around the Permo/ Triassic boundary, the early-Middle Triassic cli* Corresponding author. Tel.: +31-30-253-2635; Fax: +31-30-253-5096. E-mail address: [email protected] (J.H.A. Van Konijnenburg-Van Cittert).
mate appears to have lacked climatic zonality and seems to have been more or less uniformly warm (Dobruskina, 1994). The latest Triassic and the Early and Middle Jurassic eras are marked by major climatic moistening, indicated for example by large-scale formation of coal. Climatic zonality is present and in general we can recognise a temperate^warm, a subtropical and a tropical belt during the rest of the Mesozoic (Vakhrameev, 1991). At the beginning of the Late Jurassic warming set in, followed by aridisation of the climate and during the Early Cretaceous extensive arid zones prevailed in both the Northern and Southern Hemispheres (Vakhrameev, 1991). Ideas on fern ecology during the Mesozoic are usually quite simple: ferns generally grew in relatively warm and moist environments, ranging from coal-forming swamps to riverbanks and
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formed the understorey £ora in the forest vegetation. Ferns were the dominant herbaceous plants during most of the Mesozoic and made their ¢rst major appearance in the Mesozoic open conifer forests where according to many authors (e.g. Thomas, 1985) they must have formed the understorey. Even Vakhrameev in his book on Jurassic and Cretaceous £oras and climates (1991) merely indicates that ferns are moisture-loving plants. However, this picture is too general, especially during the warmer and more arid Late Jurassic and Early Cretaceous, because we have found evidence of ferns that were able to adapt to these changing conditions. Some of these species have been preserved mainly or only as fusain, indicating not only that wild¢res had occurred frequently at that time but also that ferns grew in such stress-related environments. In the Late Jurassic of Sutherland these are, e.g. Phlebopteris dunkeri, Hausmannia buchii, Gleichenites cycadina (Van der Burgh and Van Konijnenburg-Van Cittert, 1984; Van Konijnenburg-Van Cittert and Van der Burgh, 1996). This is indeed also true in the Early Cretaceous in England where the most widespread fossils are charred fern leaf fragments of Weichselia, Gleichenia and Matonidium (Watson and Alvin, 1996). The aim of this paper is to give an overview of fern ecology in Eurasia during a large part of the Mesozoic (Late Triassic to Early Cretaceous). The paper will also assess if the ability of ferns to adapt to a more arid climate is widespread or only occurs in certain families or in just certain genera or species. 1.2. Peat-forming ferns In this respect, the di¡erent compositions of peat-forming fern £oras is interesting, especially during the Liassic when peat formation took place in various areas (e.g. Hungary, Romania, Iran). The ferns that partook in the mainly Liassic peat formation (resulting in coal) vary from area to area. Some fern species belong to the peatforming plants in one area, but grew along riverbanks in other areas. Thus, they were able to occupy various niches. A short overview of three Liassic fern £oras
where peat formation took place is presented in Table 1. As shown, some of the species occur in all £oras, others do not. Todites princeps, for example, is a peat-forming plant in Hungarian £ora but never occurs in this setting in the Iranian £oras. Marattia does not form peat in Romania and it is even a very rare member of that £ora. Clathropteris meniscoides is a very common fossil in the coal-bearing strata of Hungary and it occurs in both the Romanian and Iranian £oras but never formed peat there. In Romania, Cladophlebis denticulata is by far the most important fern in the coal layers. It occurs both in the Hettangian and Sinemurian and according to M.E. Popa (personal communication, 2000), it grew mainly when the marshes (in which Schizoneura carcinoides was by far the most important plant) were ¢lling with detrital material. During the rest of the time, C. denticulata stayed on the edges of the marsh, as did Thaumatopteris brauniana and Cladophlebis sp. nov. during the Hettangian and Phlebopteris woodwardii, Matonia braunii and Dictyophyllum nilssonii during the Hettangian and the base of the Sinemurian.
2. Taxonomic approach 2.1. Marattiaceae In the Triassic, the Marattiaceae are well represented by the genera Asterotheca and Danaeopsis, a forerunner of Angiopteris rather than Danaea (see Tidwell and Ash, 1994). The genus Marattiopsis was for the ¢rst time recorded in the Late Triassic and di¡ers only from the living genus Marattia in age. Therefore, some of its Jurassic species were reassigned to Marattia, especially when both sterile and fertile specimens were known. The genus Angiopteris was ¢rst recorded from the Middle Jurassic £ora of Yorkshire (Van Cittert, 1966; Hill, 1987; Hill and Camus, 1986). These marattialean ferns occur in Yorkshire mainly in £oodplain deposits and particularly in light-grey to yellowish clays (Harris, 1961; Hill, 1987; Van Konijnenburg-Van Cittert and Morgans, 1999).
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To my knowledge, the Mesozoic Marattiaceae have always lived under rather warm, moist circumstances often probably as understorey in forests. Possibly some species were tree ferns although this possibility has never been demonstrated by ¢nds of their trunks. The leaves of the marattialean ferns were usually large and rather thin, indicating a moist environment. Furthermore, as mentioned above, some were peatforming ferns in the Liassic. However, there may be one exception; Van Konijnenburg-Van Cittert and Passoni (1998) and Passoni and Van Konijnenburg-Van Cittert (submitted) are describing a Carnian leaf from northern Italy as a new species of Pseudodanaeopsis (see Plate I, 1). This leaf might have belonged to a seedfern because numerous, large sterile specimens have been found but no fertile fern material at all. However, it might also have been a fern that grew in or near a mangrove just like the living Acrostichum (Pteridaceae). The latter genus has venation that is comparable to that of the Pseudodanaeopsis n. sp. A (which demonstrates hair bases between the vein meshes as well, see Plate I, 1), and it forms sporangia only during a very short period of time when circumstances are favourable for spore dispersal. However, as it is not even certain that this Pseudodanaeopsis is a fern, we certainly cannot say that it might be a marattialean fern just because the venation is so like that of the living Danaeopsis. The fossiliferous layers in which this new Pseudodanaeopsis species
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was found consist of silty marls which were interpreted as bottom deposits from a lagoon interposed between deltas and carbonate platforms (Gnaccolini and Jadoul, 1988). This does not contradict the possibility of it being a fern living in or near a mangrove. 2.2. Osmundaceae The Osmundaceae have an extensive Mesozoic record of permineralised stems (Palaeosmunda, Ashicaulis, Millerocaulis, Osmundacaulis) and both sterile (Cladophlebis) and fertile (Osmundopsis, Todites, Raphaelia) foliage remains (Tidwell and Ash, 1994; Collinson, 1996). However, many Cladophlebis species are based only on sterile material and cannot, therefore, be assigned unequivocally to the family. A combination of trunk remains and foliage has been recorded from the Liassic of Romania (Popa, 2000), where carbonised trunks (diameter 10^30 cm) belonging to Cladophlebis denticulata were found in growth position in a palaeosol together with a monospeci¢c assemblage of C. denticulata foliage. During the Mesozoic, the Osmundaceae were probably ferns that grew under warm, humid circumstances, either along riverbanks, or in freshwater marshes where they often formed peat resulting in coal (see above) in the Liassic of Hungary, Romania and Iran. Even the few coaly layers that were found in the Middle Jurassic of Yorkshire contained a large amount of Osmunda-
Table 1 Major coal generating ferns in three Liassic coal beds Hungary Marattia hoerensis Cladophlebis spp.a Todites roessertiia Todites princepsa Thaumatopteris brauniana Dictyophyllum nilssoniia Clathropteris meniscoidesa Phlebopteris angustiloba Phlebopteris muensteri
Romania
Iran b
Cladophlebis denticulata Cladophlebis sp. nov.
Marattia intermediaa Cladophlebis nebbensis
Thaumatopteris brauniana Dictyophyllum nilssonii
Dictyophyllum nilssonii
Phlebopteris woodwardii Phlebopteris muensteri/Matonia braunii
Phlebopteris muensteria
The data from Romania were provided by Dr. M. Popa (Bucharest); those from Hungary by Dr. M. Barbacka from Budapest. a This indicates that these ferns form an important part of the £ora. b This means that they are the most dominant fern in the coal beds.
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ceous remains (Muir, 1964; see Plate I, 2). However, the osmundaceous macroremains in Yorkshire were mainly found in £oodplain deposits, siltstones, clays, etc. (Van Konijnenburg-Van Cittert and Morgans, 1999). The Early and Middle Triassic fern Anomopteris mougeotii known from France and Italy has sporangial features that suggest a close relationship to the Osmundaceae, especially the living genus Todea and the fossil Todites. However, the presence of aphlebia at the pinna bases and a W-shaped vascular bundle do not occur in this family (Grauvogel-Stamm and Grauvogel, 1980). Anomopteris might have been adapted to living in ecologically unstable environments such as the borders of sedimentary basins (Grauvogel-Stamm and Grauvogel, 1980; personal observation in Anisian and Ladinian £oras in the Dolomites where volcanism was rather common and where large Anomopteris remains were found in close association with, e.g. fossil ¢sh, brachiopods, ammonites, etc.). 2.3. Schizaeaceae The ¢rst unequivocal occurrences of members of this family are in the Liassic (Stachypteris in China) or Middle Jurassic (Klukia all over the world; Plate I, 3). The a⁄nity of these genera lies with the living Lygodium rather than with Anemia, although the foliage does not resemble that of the former genus (Van Konijnenburg-
Plate I. 1.
2.
3.
4.
Pseudodanaeopsis sp.; U5.5. Detail of venation of this impression fossil. This plant may have been either a seedfern or possibly a mangrove fern comparable to the living Acrostichum. Note the dots between the vein meshes which indicate hair bases. Cladophlebis denticulata (Brongniart) Fontaine; U1. Part of a large sterile frond (compression). This species was often a coal former during the Jurassic. Klukia exilis (Philips) Raciborski; U1. Example of a Jurassic schizaeaceous fern (compression) that probably lived along riverbanks. Phlebopteris dunkeri (Schenk) Schenk; U2. This species is almost always preserved as fusain in the Late Jurassic £ora of Sutherland.
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Van Cittert, 1991). In the Early Cretaceous, the family became widespread with genera such as Ru¡ordia, Pelletixia and Schizaeopsis which are thought to be Anemia-like (Tidwell and Ash, 1994; Collinson, 1996) and members of the living genus Anemia have been recorded from strata of that age (e.g. Skog and Dilcher, 1994). As to the ecology of the Schizaeaceae, all these ferns probably preferred warm, humid environments as they were mainly recorded from sandstones and clays in the subtropical belt of the Northern Hemisphere (Vakhrameev, 1991). They may have grown along riverbanks or as understorey in forests (Dettmann and Cli¡ord, 1992; Skog and Dilcher, 1994; Watson and Alvin, 1996). Pelletixia had rather enclosed sori, perhaps comparable with the sporocarps of the water fern family Marsileaceae (Bierhorst, 1971). These sporocarps are highly resistant to desiccation and are known to retain viability over several years (Watson and Alvin, 1996). Crabtree (1988) suggested for the schizaeaceous ferns such as Anemia fremontii from the Mid-Cretaceous Albino member (MT, USA) an environment of swampy mud £ats or shallow, ephemeral lake beds situated on a delta adjacent to the mid-continental epeiric sea. So far, no record of coal-bearing strata with any of these fern genera is known. 2.4. Gleicheniaceae The family has been traced back to the Permian (Rothwell, 1996), although some of the older fossils, such as Oligocarpia and Sermeya, are now attributed to the fossil family Sermeyaceae (Tidwell and Ash, 1994; Collinson, 1996). Also there is some doubt about a de¢nite attribution to the family of some of the older fossils because they lack the pseudo-dichotomous branching pattern typical of the Gleicheniaceae. Living Gleicheniaceae often grow in open, sunny places but often with their rhizomes embedded in damp soil. In the tropics, they may cover vast, almost impregnable areas and are thus considered to be a very di⁄cult weed on agricultural ¢elds in those areas (Smith, 1955; Walker, 1994). The putative Permian and Triassic members of this family may well have lived under the ‘normal’
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humid, rather warm conditions that prevailed for most ferns. There is no evidence whatsoever that any of these fossils have lived under di¡erent circumstances. The Gleicheniaceae are not common in most Jurassic assemblages either, e.g. they are absent in the famous Yorkshire Jurassic £ora and only a few specimens of presumably Gleicheniaceous origin have been found in Iran. However, in the Late Jurassic £ora of Scotland Gleichenites cycadina is one of the most common fossils and it almost always occurs in rather small fragments of fusain (Plate II, 5). This latter occurrence probably represents ferns dwelling on upland areas that were often subject to ¢re (Van der Burgh and Van Konijnenburg-Van Cittert, 1984; Van Konijnenburg-Van Cittert and Van der Burgh, 1996). The same preservation has been reported for Gleichenites and Gleichenia species in the Wealden of England (Harris, 1981; Watson and Alvin, 1996). The Early Cretaceous species Gleichenia chaloneri might also have been living under stress (indicated by the presence of trichomes and sunken stomata ; Herendeen and Skog, 1998), but has also been preserved as fusain. The same applies to Late Cretaceous Boodlepteris-like material
Plate II. 1.
2.
3.
4.
5.
Dictyophyllum rugosum Lindley et Hutton; U0.5. Here associated with Todites williamsonii (Brongniart) Seward; both species (usually found as compressions which is the case here as well) are often preserved as large fronds, indicating probably a humid, subtropical climate. Hausmannia buchii Andrae; U2. This Hausmannia species is almost always preserved as fusain in the Late Jurassic £ora of Sutherland. Hausmannia dichotoma Dunker; U1. This Hausmannia species is never preserved as fusain in the Late Jurassic £ora of Sutherland but is a compression. Coniopteris simplex (Lindley et Hutton) Harris; U2. There is no indication that any Coniopteris species was a tree fern during the Jurassic. They are always found as smaller or larger frond fragments, either as impressions or as compressions. The latter is the case here. Gleichenites cycadina (Schenk) Seward; U1. This species is always preserved as fusain in the Late Jurassic £ora of Sutherland.
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(Gandolfo et al., 1997) and a Tertiary Gleichenia species from Australia (Blackburn and Sluiter, 1994). There the pinnules are often found charcoali¢ed whilst the scaly, woody rhizomes occupy laterally extensive beds. This fossil material is almost identical to the living G. dicarpa, a ¢re-tolerant species (Blackburn and Sluiter, 1994). However, Gleicheniaceous fossils from the Dakota Formation (Early Cretaceous, USA) occur as normal impressions and not as fusain. Skog and Dilcher (1994) suggested that these ferns grew in dense stands just as living Gleichenia, and that the tough fronds were transported over considerable distances before deposition. They might have been a major component of fern ‘savannahs or prairies’ according to Skog and Dilcher. Crabtree (1988) stated that especially gleicheniaceous ferns appear to be characteristic of various Mid-Cretaceous ash beds indicating that they were important components of an early successional (pioneer) vegetation. Cretaceous fern £oras from non-volcanic rocks typically lack gleicheniaceous ferns. 2.5. Matoniaceae This family, characterised by, e.g. a typical ‘pedal’ branching pattern for the fronds, was ¢rmly established from the Late Triassic onwards with members of the non-indusiate genus Phlebopteris, which then became widespread during the Jurassic. During the Jurassic more genera appeared, including members of the living genus Matonia with a well-developed indusium, Matonidium with a smaller indusium and Selenocarpus with non-indusiate crescent-shaped sori (Van Konijnenburg-Van Cittert, 1993; Tidwell and Ash, 1994; Collinson, 1996). In the Late Jurassic and Cretaceous bipinnate genera such as Piazopteris and Delosorus also appeared. The ecology of all these ferns can be quite variable ; some of the fronds must have been quite large and have certainly grown under humid conditions as understorey or along riverbanks. Examples of these are Selenocarpus muensterianus and Phlebopteris angustiloba in the Early Jurassic, P. polypodioides and P. tracyi in the Middle Jurassic (Ash, 1991; Philippe et al., 1998; personal observation). Others were more stress-adapted
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and the ecology of some ferns was quite variable even within one species. The most striking fern in this respect is Phlebopteris woodwardii. It is one of the peat generators in Romania (see Table 1) with beautifully preserved material that yielded in situ spores. In the Stones¢eld £ora (Bathonian, England; Seward, 1904), the species has been found as impression fragments and the fern probably grew along a riverbank. In the more or less contemporaneous Yorkshire Jurassic (where the type specimen originated; see Harris, 1961) and a £ora in northwest Scotland (Bateman et al., 2000), the species has been recorded only as fusain (charcoal), suggesting that P. woodwardii was an abundant plant of inland heaths which was only preserved in the delta as a result of burning and £ood. This situation would have been comparable to a modern English heath ¢re (Harris, 1981). A number of other Phlebopteris species were also preserved as fusain, e.g. P. dunkeri in the Late Jurassic of Scotland (Plate I, 4; Van Konijnenburg-Van Cittert and Van der Burgh, 1996) and Phlebopteris species in the English Wealden £ora (Harris, 1981; Watson and Alvin, 1996). Some members of the family were adapted to an arid climate in the Cretaceous. An example is the well-known Weichselia, which some authors classi¢ed into a separate family Weichseliaceae because of its reduced and well-protected sporangia (see Tidwell and Ash, 1994; Collinson, 1996). Weichselia remains especially have often been recorded as fusain (Harris, 1981; Vakhrameev, 1991; Watson and Alvin, 1996; Collinson et al., 1999). Another example is the genus Piazopteris that was growing in dry localities in tropical and subtropical areas during the Late Jurassic and Early Cretaceous. Both genera are absent from the warm^moderate zone of the Northern Hemisphere (sensu Vakhrameev, 1991). 2.6. Dipteridaceae This family, again with a typical frond-branching pattern resembling that of the Matoniaceae, is a very important one in the Mesozoic (especially Late Triassic and Jurassic), with many genera (e.g. Clathropteris, Dictyophyllum, Camptopteris,
Hausmannia, Kenderlykia, Goeppertella) all over the world (Tidwell and Ash, 1994; Collinson, 1996). The only extant genus, Dipteris, is restricted to the tropical Malaysian Archipelago similar to the living Matoniaceae. Extant Dipteris includes a species growing on streambanks where the canopy is open, and also species that are colonisers of disturbed sites and exposed ridges (Cantrill, 1995). During the Mesozoic the Dipteridaceae mainly occupied moist localities in the temperate^warm and subtropical zones. Some members of the family must have been quite large, e.g. some Dictyophyllum species judging by the long and stout petiole fragments (over 1 m long) and large frond remains that have been found (Plate II, 1; personal observation). According to Barale (1990) Dictyophyllum and Clathropteris migrated with the warm, humid climate from southeast Asia (Late Triassic) to southwestern Asia and Europe (Early Jurassic). During the Jurassic, some species, especially of Hausmannia, adapted to more stress-related environments. For example, Hausmannia dichotoma (Plate II, 3) might have occupied a brackish habitat in the Late Jurassic Sutherland £ora (Van Konijnenburg-Van Cittert and Van der Burgh, 1996), and Watson and Alvin (1996) record that this species had leathery leaves in the English Wealden. H. buchii has been recorded as fusain in the Sutherland £ora (Plate II, 2; Van Konijnenburg-Van Cittert and Van der Burgh, 1996), although it is also known as normal compressions in other Jurassic £oras (e.g. Popa, 2000). Rare fusain fragments of Hausmannia species were also recorded from Bathonian assemblages in Skye (northwest Scotland) by Bateman et al. (2000). Cantrill (1995) interpreted the Antarctic species Hausmannia papilio as a streamside dweller and coloniser of disturbed sites just like some extant Dipteris species. It is quite possible that, with the oncoming warming during the Cretaceous, members of the family could not adapt to these warmer and more arid circumstances. As a result they died out, except for the genus Hausmannia (the only genus recorded from the Cretaceous) which is indistinguishable from living Dipteris that survived in its refugium.
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2.7. Dicksoniaceae
2.8. Cyatheaceae
The Dicksoniaceae are sometimes included in the Cyatheaceae s.l. (e.g. Lovis, 1977), but other authors separate them on the basis of their marginal sori contrasting with the super¢cial sori in the Cyatheaceae s.s. (see Tidwell and Ash, 1994); this latter opinion is accepted here. The family ¢rst appeared in the Late Triassic and is especially abundant in the Jurassic and Early Cretaceous with leaf remains of many species, particularly of Coniopteris, all over the world. This genus, just as other fossil Mesozoic dicksoniaceous genera such as Eboracia, Kylikipteris and Dicksonia, has been recorded from clays, sandstones and siltstones, and the ferns probably preferred a warm, moist habitat (Plate II, 4) (Vakhrameev, 1991). Present-day Dicksoniaceae are tree ferns occurring in both tropical and temperate rain forests in the Southern Hemisphere. It is generally thought that the majority of the fossils were tree ferns as well and occupied more or less the same habitats as the living ones (Vakhrameev, 1991; Tidwell and Nishida, 1993). However, for at least the Late Triassic and the majority of the Jurassic fossils, there is no proof of this. The ¢rst possible tree fern stems that might be attributed to the Dicksoniaceae/Cyatheaceae (Cyatheaceae s.l.) date from the Late Jurassic (Tidwell and Nishida, 1993). There are more records in the Cretaceous, mainly from the USA (e.g. Tidwell and Nishida, 1993 from the Early Cretaceous of South Dakota; Lantz et al., 1999 from the Aptian of California ; Hilton et al., 1997 from the Late Cretaceous of California). Most of these fossils are stems that resemble living dicksoniaceous stems more closely than cyatheaceous stems. An exception in ecology may be the Late Jurassic^Early Cretaceous fern Onychiopsis psilotoides which reveals a remarkable protection of its sporangia as they are completely enclosed in thick-walled fertile bodies. Moreover, the sterile segments are coriaceous in texture and, therefore, this plant may have been adapted to high-stress environments at the margin of a more or less brackish bay (Friis and Pedersen, 1990).
The Cyatheaceae s.s. is a family of living tropical and subtropical tree ferns that is rather poorly represented by fossil remains. It is ¢rst recorded in the Jurassic from leaf remains in Poland (Alsophilites) and stems in Australia (Oguracaulis) (e.g. Tidwell and Ash, 1994; Collinson, 1996). Both stems and leaf remains are more common in the Cretaceous (e.g. Krassilov, 1978 from Mongolia), and the ¢rst record of sterile and fertile foliage attributed to the living genus Cyathea is from the Early Cretaceous of Patagonia (Villar de Seoane, 1999). It is thought that this family has not changed greatly morphologically and anatomically from that time to the present (Villar de Seoane, 1999). The same probably applies to the habitats where the plants lived. 2.9. Tempskyaceae This family is only known from large petri¢ed ‘false’ stems that actually consist of numerous single stems bound together by masses of adventitious roots (e.g. Tidwell and Ash, 1994; Collinson, 1996). These trunks have been reported mainly from Lower and Middle Cretaceous sediments in Laurasia. The associated fronds were described by Tidwell and Hebbert (1992) as thin and delicate when they reported the discovery of some trunks in the position of growth embedded in undisturbed carbonaceous shale. The presence of pyritic sulphur in the shale indicates a swampy habitat (Tidwell and Hebbert, 1992; Tidwell and Ash, 1994; Watson and Alvin, 1996). 2.10. Hymenophyllaceae There was no de¢nite Mesozoic record of the ‘¢lmy ferns’ until recently, when Deng (1997) described Eogonocormus cretaceum from the Early Cretaceous of northeast China. This thalloid fossil leaf resembles the Hepaticae, but detailed study of the leaf, sorus, sporangium and spore morphology revealed that this plant has to be attributed to the Hymenophyllaceae. Eogonocormus is a small fern with fronds only several centimetres high and a creeping rhizome bearing slender, hair-like roots.
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Many of the fronds were connected with the rhizomes, covering the surface of the mudstone in which the fossils were found. This suggests that they were fossilised more or less in situ, and that the fern, like its living relatives, probably grew in humid areas close to water. 2.11. Leptosporangiate ferns with vertical annuli Very few convincing ‘polypodiaceous’ ferns have been described from the earlier parts of the Mesozoic (Tidwell and Ash, 1994; Collinson, 1996), although many specimens have been assigned to this group in the past. One of the problems is the lack of diagnostic characters. The main character of the group is the leptosporangiate sporangium that has a vertical annulus and usually contains 64 spores. Furthermore, the sporangia in a sorus do not mature at the same time, a feature that is often di⁄cult to observe in fossil material. The earliest known representative so far is Aspidistes thomasii, ¢rst described from the Middle Jurassic of Yorkshire (Harris, 1961), with a tentative assignment to ?Aspideae. Lovis (1977) concluded that it might represent a member of the Thelypteridaceae. Based on re-examination of the type material, Collinson (1996) proposed that A. thomasii could best be treated as ?Thelypteridaceae. Two other species of Aspidistes (A. beckeri from the Jurassic of Israel and A. sewardii from the Cretaceous of England) most likely belong to the Matoniaceae (Lovis, 1977). There are more records of polypodiaceous fossils from the Early Cretaceous, e.g. members of the genera Australopteris (showing the vertical annulus and comparable to the living genus Drynaria) and Onoclea. The latter is especially poorly characterised (Tidwell and Ash, 1994). Deng (1995) summarised several polypodiaceous species from China, i.e. a species of Athyrium, one of Asplenium and two of Dryopteris. All fossils yielded the monolete spores typical of many Polypodiaceae and the sporangia demonstrated a vertical annulus as well. These ferns have mediumsized thin fronds usually found in coal-bearing sediments (mostly mudstones or siltstones), which led Deng (2002) suggest that the parent ferns lived
under warm, humid conditions close to a wetland depositional site. The only other Mesozoic member of this group is fertile fern foliage from the Early Cretaceous of Antarctica described by Cantrill (1998) as Lophosoria cupulatus. The foliage is morphologically similar to that of the form genus Gleichenites but has been assigned by him to the monospeci¢c fern family Lophosoriaceae. This assignment was based on the absence of the pseudo-dichotomous branching pattern (with a sleeping bud) typical for the living Gleicheniaceae, and on the presence of the distinctive spore morphology (cingulate with proximal contact faces having a raised foveolate pad) typical of the living Lophosoria. Moreover, the soral features also supported placement in the Lophosoriaceae. The living L. quadripinnata is an opportunist invading disturbed, open areas and the fossil L. cupulatus might have occupied a similar habitat (Cantrill, 1998).
3. Conclusions ^ The ecology of the majority of Mesozoic ferns con¢rms the common view that they grew under moist, rather warm conditions either in marshes, along riverbanks or as understorey in forests. This is especially true in the case of the Marattiaceae, Osmundaceae, Cyatheaceae, Tempskyaceae, Dipteridaceae, Dicksoniaceae and Schizaeaceae, although in the latter three families some mainly Cretaceous taxa may have been opportunists colonising disturbed ground after volcanic eruptions. ^ Ferns forming peat (resulting in coal) were common, especially in the Early Jurassic. However, the composition of these fern £oras was markedly di¡erent in various regions (see Table 1), although members of the Osmundaceae, Matoniaceae and Dipteridaceae were always present. Marattiaceous ferns partook in peat formation only in some areas, whilst members of other families played an unimportant role in the peat-forming process or have never been recorded from these £oras (e.g. Schizaeaceae, Gleicheniaceae). ^ Members of certain families, especially Matoniaceae (some Phlebopteris species and Weichse-
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lia) and Gleicheniaceae (Gleichenites), were able to adapt to the more stress-related semiarid and ¢re-prone conditions that developed since the Late Jurassic. Of course, this does not imply that all members of these families showed the same ecological adaptations. ^ In the genus Hausmannia of the Dipteridaceae, some species (e.g. H. dichotoma) developed an adaptation to brackish habitats, others (e.g. H. buchii) were recorded as fusain in some £oras but as compression fossils in other £oras. ^ Onychiopsis psilotoides from the Dicksoniaceae might also have been adapted to high-stress environments, judging from the coriaceous texture of its fronds and the remarkable protection of its sporangia. ^ Assuming correct taxonomic determinations, some taxa (e.g. Phlebopteris woodwardii, Hausmannia buchii) grew under di¡erent environmental circumstances at di¡erent times, or even during the same periods.
Acknowledgements I gratefully acknowledge the help of Dr. Maria Barbacka, Budapest, and Dr. Mihai Popa, Bucharest, who provided me with the data on Liassic coal formation in Hungary and Romania, respectively. Discussions with Dr. Margaret Collinson are very much appreciated. This paper benefited greatly from remarks and suggestions made by Dr. Sid Ash and Dr. Joan Watson. References Ash, S., 1991. A new Jurassic Phlebopteris (Plantae, Filicales) from the Wallowa Terrane in the Snake River Canyon, Oregon and Idaho. J. Paleontol. 65, 322^329. Barale, G., 1990. Les strate¤gies adaptives chez les ve¤ge¤taux du Trias supe¤rieur au Cre¤tace¤ infe¤rieur dans l’aire eurosinienne, en relation avec l’e¤volution du climat. C.R. Acad. Sci. Paris 311, Ser. II, 265^269. Bateman, R.M., Morton, N., Dower, B.L., 2000. Early Middle Jurassic plant communities in northwest Scotland: Paleoecological and Paleoclimatic signi¢cance. Geores. Forum 6, 501^512. Bierhorst, D.W., 1971. Morphology of Vascular Plants. Macmillan, New York, 500 pp.
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Blackburn, D.T., Sluiter, I.R.K., 1994. The Oligo^Miocene £oras of southeastern Australia. In: Hill, R.S. (Ed.), History of the Australian Vegetation: Cretaceous to Recent. Cambridge University Press, Cambridge, pp. 328^367. Cantrill, D.J., 1995. The occurrence of the fern Hausmannia Dunker (Dipteridaceae) in the Cretaceous of Alexander Island, Antarctica. Alcheringa 19, 243^254. Cantrill, D.J., 1998. Early Cretaceous fern foliage from President Head, Snow Island, Antarctica. Alcheringa 22, 241^ 258. Collinson, M.E., 1996. ‘What use are fossil ferns?’ ^ 20 years on: with a review of the fossil history of extant Pteridophyte families and genera. In: Camus, J.M., Gibby, M., Johns, R.J. (Eds.), Pteridology in Perspective. Royal Botanic Gardens, Kew, pp. 349^394. Collinson, M.E., Featherstone, C., Cripps, J.A., Nichols, G.J., Scott, A.C., 1999. Charcoal-rich plant debris accumulations in the Lower Cretaceous of the Isle of Wight, England. Acta Palaeobot. Suppl. 2, 93^105. Crabtree, D.R., 1988. Mid-Cretaceous ferns in situ from the Albino member of the Mowry Shale, southwestern Montana. Palaeontographica B 209, 1^27. Deng, S., 1995. New materials of the Early Cretaceous monolete spore ferns and their taxonomic study. Acta Bot. Sin. 37, 483^491. Deng, S., 1997. Eogonocormus ^ a new Early Cretaceous fern of Hymenophyllaceae from China. Aust. Syst. Bot. 10, 59^ 67. Deng, S., 2002. Ecology of the Early Cretaceous ferns of Northeast China. Rev. Palaeobot. Palynol. 119, 93^112. Dettmann, M.E., Cli¡ord, H.T., 1992. Phylogeny and biogeography of Ru¡ordia, Mohria and Anemia (Schizaeaceae) and Ceratopteris (Pteridaceae): evidence from in situ and dispersed spores. Alcheringa 16, 269^314. Dobruskina, I.A., 1994. Triassic Floras of Eurasia. Oesterr. Akad. Wiss. Schriftenr. Erdwiss. Komm. 10, 422 pp. Friis, E.M., Pedersen, K.R., 1990. Structure of the Lower Cretaceous fern Onychiopsis psilotoides from Bornholm, Denmark. Rev. Palaeobot. Palynol. 66, 47^63. Gandolfo, M.A., Nixon, K.C., Crepet, W.L., Ratcli¡e, G.E., 1997. A new fossil fern assignable to Gleicheniaceae from Late Cretaceous sediments of New Jersey. Am. J. Bot. 84, 483^493. Gnaccolini, M., Jadoul, F., 1988. Un sistema deposizionale delta^laguna^piattaforma carbonatica nel Carnico Lombardo (Triassico superiore, Alpi meridionali, Italia). Riv. Ital. Paleontol. Stratigr. 93, 447^468. Grauvogel-Stamm, L., Grauvogel, L., 1980. Morphologie et anatomie d’Anomopteris mougeoti Brongniart, une fouge're du Buntsandstein supe¤rieure des Vosges (France). Sci. Geol. Bull. 33, 53^66. Harris, T.M., 1961. The Yorkshire Jurassic Flora, I. Thallophyta^Pteridophyta. British Museum (Natural History), London, 212 pp. Harris, T.M., 1981. Burnt ferns from the English Wealden. Proc. Geol. Assoc. 92, 47^58. Herendeen, P.S., Skog, J., 1998. Gleichenia chaloneri ^ a new
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fossil fern from the Lower Cretaceous (Albian) of England. Int. J. Plant Sci. 159, 870^879. Hill, C.R., 1987. Jurassic Angiopteris (Marattiales) from North Yorkshire, UK. Rev. Palaeobot. Palynol. 51, 65^94. Hill, C.R., Camus, J.M., 1986. Evolutionary cladistics of marattialean ferns. Bull. Br. Mus. (Nat. Hist.) Bot. 14, 219^300. Hilton, R., Antuzzi, P., Arens, N.C., Erwin, D., 1997. A tree fern from the Late Cretaceous Chico Formation of Northern California. Geological Society of America, Boulder, CO, Abstr. Progr., p. A-97. Krassilov, V.A., 1978. Mesozoic lycopods and ferns from the Bureja Basin. Palaeontographica B 166, 16^29. Lantz, T.C., Rothwell, G.W., Stockey, R.A., 1999. Conantiopteris schuchmanii, gen. et sp. nov., and the role of fossils in resolving the phylogeny of Cyatheaceae s.l.. J. Plant Res. 112, 361^381. Lovis, J.D., 1977. Evolutionary patterns and process in ferns. Adv. Bot. Res. 4, 230^424. Muir, M.D., 1964. The Palaeoecology of the Small Spores of the Middle Jurassic of Yorkshire. Ph.D. Thesis, University of London (unpublished). Passoni, L., Van Konijnenburg-Van Cittert, J.H.A. submitted. New taxa of fossil Carnian plants from Mount Pora (Bergamasc Alps; Northern Italy) Rev. Palaeobot. Palynol.. Philippe, M., Thevenard, F., Barale, G., Ferry, S., Guignard, G., 1998. Middle Bathonian £oras and phytocoenoses of France. Palaeogeogr., Palaeoclimatol., Palaeoecol. 143, 135^158. Popa, M.E., 2000. Early Jurassic Land£ora of the Getic Nappe. Ph.D. Thesis, University of Bucharest (unpublished). Rothwell, G.W., 1996. Phylogenetic relationships of ferns: a palaeobotanical perspective. In: Camus, J.M., Gibby, M., Johns, R.J. (Eds.), Pteridology in Perspective. Royal Botanic Gardens, Kew, pp. 395^404. Seward, A.C., 1904. The Jurassic Flora, II. Liassic and Oolithic Floras of England. Catalogue of the Mesozoic Plants in the Department of Geology, British Museum (Natural History), London, 192 pp. Skog, J.E., Dilcher, D.L., 1994. Lower vascular plants of the Dakota Formation in Kansas and Nebraska, USA. Rev. Palaeobot. Palynol. 80, 1^18. Smith, G., 1955. Cryptogamic Botany, Vol. II. Bryophytes and Pteridophytes. McGraw-Hill, Tokyo, 399 pp. Thomas, B.A., 1985. Pteridophyte success and past biota ^ a palaeobotanist’s approach. Proc. R. Soc. Edinburgh 86B, 423^430.
Tidwell, W.D., Ash, S.R., 1994. A review of selected Triassic to Early Cretaceous ferns. J. Plant Res. 107, 417^442. Tidwell, W.D., Hebbert, N., 1992. Species of the Cretaceous tree fern Tempskya from Utah. Int. J. Plant Sci. 153, 513^ 528. Tidwell, W.D., Nishida, H., 1993. A new fossilized tree fern stem, Nishidacaulis burgii gen. et sp. nov., from Nebraska, South Dakota, USA. Rev. Palaeobot. Palynol. 78, 55^67. Vakhrameev, V.A., 1991. Jurassic and Cretaceous Floras and Climates of the Earth. Cambridge University Press, Cambridge, 318 pp. Van Cittert, J.H.A., 1966. Palaeobotany of the Mesophytic, II. New and noteworthy Jurassic ferns from Yorkshire. Acta Bot. Neerl. 15, 284^289. Van der Burgh, J., Van Konijnenburg-Van Cittert, J.H.A., 1984. A drifted £ora from the Kimmeridgian (Upper Jurassic) of Lothbeg Point, Sutherland, Scotland. Rev. Palaeobot. Palynol. 43, 359^396. Van Konijnenburg-Van Cittert, J.H.A., 1991. Diversi¢cation of spores in fossil and extant Schizaeaceae. In: Blackmore, S., Barnes, S.H. (Eds.), Pollen and Spores. Clarendon Press, Oxford, pp. 103^118. Van Konijnenburg-Van Cittert, J.H.A., 1993. A review of the Matoniaceae based on in situ spores. Rev. Palaeobot. Palynol. 78, 235^267. Van Konijnenburg-Van Cittert, J.H.A., Morgans, H.S., 1999. The Jurassic Flora of Yorkshire. Palaeontological Association Field Guides to Fossils 8, The Palaeontological Association, London, 134 pp. Van Konijnenburg-Van Cittert, J.H.A., Van der Burgh, J., 1996. Review of the Kimmeridgian £ora of Sutherland, Scotland, with reference to the ecology and in situ pollen and spores. Proc. Geol. Assoc. 107, 97^105. Van Konijnenburg-Van Cittert, J.H.A., Passoni, L., 1998. Carnian (Triassic) £ora from Mount Pora (Northern Italy). The 5th European Palaeobotanical and Palynological Conference, Cracow, Abstr. Vol., p. 189. Villar de Seoane, L., 1999. Estudio comparado de Cyathea cyathifolia comb. nov. del Cretacico inferior de patagonia, Argentina. Rev. Esp. Paleontol. 14, 157^163. Walker, L.R., 1994. E¡ects of fern thickets on woodland development on landslides in Puerto Rico. J. Veg. Sci. 5, 525^ 532. Watson, J., Alvin, K.L., 1996. An English Wealden £oral list, with comments on possible environmental indicators. Cretaceous Res. 17, 5^26.
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Ecology of some Late Triassic to Early Cretaceous ferns in Eurasia J.H.A. Van Konijnenburg-Van Cittert Laboratory of Palaeobotany and Palynology, University of Utrecht, Budapestlaan 4, 3584 CD Utrecht, The Netherlands
Abstract During the Late Triassic to Early Cretaceous the majority of ferns in Eurasia grew under warm (subtropical to tropical) conditions in moist environments, including peat-forming swamps, freshwater marshes, riverbanks and understorey vegetation in forests. Most of these ferns are assigned to families Marattiaceae, Osmundaceae, Schizaeaceae, Dicksoniaceae and Cyatheaceae. However, some ferns grew under much drier conditions or otherwise stress-related circumstances especially during the Jurassic and Early Cretaceous either as pioneer plants in coastal areas, on mountain slopes or on heathland. These include the Matoniaceae and Gleicheniaceae and to a lesser extent also the Dipteridaceae. Some species have so far been mainly or only recorded as fusain, indicating not only that wildfires occurred frequently at that time but also that ferns grew in such environments. Some specific taxa may have grown under different environmental circumstances in different, or even the same, periods. . 2002 Elsevier Science B.V. All rights reserved. Keywords: ecology; ferns; Late Triassic^Early Cretaceous; Eurasia
1. Introduction 1.1. Mesozoic environments and concepts of fern ecology The Mesozoic was an era of warm climate. Absence of polar icecaps and probably even belts of cold climate is indicated by ¢nds of thermophilic plant remains in the Arctic and Antarctic (Vakhrameev, 1991). After the recovery during the Early Triassic from the dramatic climatic changes and mass extinctions around the Permo/ Triassic boundary, the early-Middle Triassic cli* Corresponding author. Tel.: +31-30-253-2635; Fax: +31-30-253-5096. E-mail address: [email protected] (J.H.A. Van Konijnenburg-Van Cittert).
mate appears to have lacked climatic zonality and seems to have been more or less uniformly warm (Dobruskina, 1994). The latest Triassic and the Early and Middle Jurassic eras are marked by major climatic moistening, indicated for example by large-scale formation of coal. Climatic zonality is present and in general we can recognise a temperate^warm, a subtropical and a tropical belt during the rest of the Mesozoic (Vakhrameev, 1991). At the beginning of the Late Jurassic warming set in, followed by aridisation of the climate and during the Early Cretaceous extensive arid zones prevailed in both the Northern and Southern Hemispheres (Vakhrameev, 1991). Ideas on fern ecology during the Mesozoic are usually quite simple: ferns generally grew in relatively warm and moist environments, ranging from coal-forming swamps to riverbanks and
0034-6667 / 02 / $ ^ see front matter . 2002 Elsevier Science B.V. All rights reserved. PII: S 0 0 3 4 - 6 6 6 7 ( 0 1 ) 0 0 1 3 2 - 4
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formed the understorey £ora in the forest vegetation. Ferns were the dominant herbaceous plants during most of the Mesozoic and made their ¢rst major appearance in the Mesozoic open conifer forests where according to many authors (e.g. Thomas, 1985) they must have formed the understorey. Even Vakhrameev in his book on Jurassic and Cretaceous £oras and climates (1991) merely indicates that ferns are moisture-loving plants. However, this picture is too general, especially during the warmer and more arid Late Jurassic and Early Cretaceous, because we have found evidence of ferns that were able to adapt to these changing conditions. Some of these species have been preserved mainly or only as fusain, indicating not only that wild¢res had occurred frequently at that time but also that ferns grew in such stress-related environments. In the Late Jurassic of Sutherland these are, e.g. Phlebopteris dunkeri, Hausmannia buchii, Gleichenites cycadina (Van der Burgh and Van Konijnenburg-Van Cittert, 1984; Van Konijnenburg-Van Cittert and Van der Burgh, 1996). This is indeed also true in the Early Cretaceous in England where the most widespread fossils are charred fern leaf fragments of Weichselia, Gleichenia and Matonidium (Watson and Alvin, 1996). The aim of this paper is to give an overview of fern ecology in Eurasia during a large part of the Mesozoic (Late Triassic to Early Cretaceous). The paper will also assess if the ability of ferns to adapt to a more arid climate is widespread or only occurs in certain families or in just certain genera or species. 1.2. Peat-forming ferns In this respect, the di¡erent compositions of peat-forming fern £oras is interesting, especially during the Liassic when peat formation took place in various areas (e.g. Hungary, Romania, Iran). The ferns that partook in the mainly Liassic peat formation (resulting in coal) vary from area to area. Some fern species belong to the peatforming plants in one area, but grew along riverbanks in other areas. Thus, they were able to occupy various niches. A short overview of three Liassic fern £oras
where peat formation took place is presented in Table 1. As shown, some of the species occur in all £oras, others do not. Todites princeps, for example, is a peat-forming plant in Hungarian £ora but never occurs in this setting in the Iranian £oras. Marattia does not form peat in Romania and it is even a very rare member of that £ora. Clathropteris meniscoides is a very common fossil in the coal-bearing strata of Hungary and it occurs in both the Romanian and Iranian £oras but never formed peat there. In Romania, Cladophlebis denticulata is by far the most important fern in the coal layers. It occurs both in the Hettangian and Sinemurian and according to M.E. Popa (personal communication, 2000), it grew mainly when the marshes (in which Schizoneura carcinoides was by far the most important plant) were ¢lling with detrital material. During the rest of the time, C. denticulata stayed on the edges of the marsh, as did Thaumatopteris brauniana and Cladophlebis sp. nov. during the Hettangian and Phlebopteris woodwardii, Matonia braunii and Dictyophyllum nilssonii during the Hettangian and the base of the Sinemurian.
2. Taxonomic approach 2.1. Marattiaceae In the Triassic, the Marattiaceae are well represented by the genera Asterotheca and Danaeopsis, a forerunner of Angiopteris rather than Danaea (see Tidwell and Ash, 1994). The genus Marattiopsis was for the ¢rst time recorded in the Late Triassic and di¡ers only from the living genus Marattia in age. Therefore, some of its Jurassic species were reassigned to Marattia, especially when both sterile and fertile specimens were known. The genus Angiopteris was ¢rst recorded from the Middle Jurassic £ora of Yorkshire (Van Cittert, 1966; Hill, 1987; Hill and Camus, 1986). These marattialean ferns occur in Yorkshire mainly in £oodplain deposits and particularly in light-grey to yellowish clays (Harris, 1961; Hill, 1987; Van Konijnenburg-Van Cittert and Morgans, 1999).
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To my knowledge, the Mesozoic Marattiaceae have always lived under rather warm, moist circumstances often probably as understorey in forests. Possibly some species were tree ferns although this possibility has never been demonstrated by ¢nds of their trunks. The leaves of the marattialean ferns were usually large and rather thin, indicating a moist environment. Furthermore, as mentioned above, some were peatforming ferns in the Liassic. However, there may be one exception; Van Konijnenburg-Van Cittert and Passoni (1998) and Passoni and Van Konijnenburg-Van Cittert (submitted) are describing a Carnian leaf from northern Italy as a new species of Pseudodanaeopsis (see Plate I, 1). This leaf might have belonged to a seedfern because numerous, large sterile specimens have been found but no fertile fern material at all. However, it might also have been a fern that grew in or near a mangrove just like the living Acrostichum (Pteridaceae). The latter genus has venation that is comparable to that of the Pseudodanaeopsis n. sp. A (which demonstrates hair bases between the vein meshes as well, see Plate I, 1), and it forms sporangia only during a very short period of time when circumstances are favourable for spore dispersal. However, as it is not even certain that this Pseudodanaeopsis is a fern, we certainly cannot say that it might be a marattialean fern just because the venation is so like that of the living Danaeopsis. The fossiliferous layers in which this new Pseudodanaeopsis species
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was found consist of silty marls which were interpreted as bottom deposits from a lagoon interposed between deltas and carbonate platforms (Gnaccolini and Jadoul, 1988). This does not contradict the possibility of it being a fern living in or near a mangrove. 2.2. Osmundaceae The Osmundaceae have an extensive Mesozoic record of permineralised stems (Palaeosmunda, Ashicaulis, Millerocaulis, Osmundacaulis) and both sterile (Cladophlebis) and fertile (Osmundopsis, Todites, Raphaelia) foliage remains (Tidwell and Ash, 1994; Collinson, 1996). However, many Cladophlebis species are based only on sterile material and cannot, therefore, be assigned unequivocally to the family. A combination of trunk remains and foliage has been recorded from the Liassic of Romania (Popa, 2000), where carbonised trunks (diameter 10^30 cm) belonging to Cladophlebis denticulata were found in growth position in a palaeosol together with a monospeci¢c assemblage of C. denticulata foliage. During the Mesozoic, the Osmundaceae were probably ferns that grew under warm, humid circumstances, either along riverbanks, or in freshwater marshes where they often formed peat resulting in coal (see above) in the Liassic of Hungary, Romania and Iran. Even the few coaly layers that were found in the Middle Jurassic of Yorkshire contained a large amount of Osmunda-
Table 1 Major coal generating ferns in three Liassic coal beds Hungary Marattia hoerensis Cladophlebis spp.a Todites roessertiia Todites princepsa Thaumatopteris brauniana Dictyophyllum nilssoniia Clathropteris meniscoidesa Phlebopteris angustiloba Phlebopteris muensteri
Romania
Iran b
Cladophlebis denticulata Cladophlebis sp. nov.
Marattia intermediaa Cladophlebis nebbensis
Thaumatopteris brauniana Dictyophyllum nilssonii
Dictyophyllum nilssonii
Phlebopteris woodwardii Phlebopteris muensteri/Matonia braunii
Phlebopteris muensteria
The data from Romania were provided by Dr. M. Popa (Bucharest); those from Hungary by Dr. M. Barbacka from Budapest. a This indicates that these ferns form an important part of the £ora. b This means that they are the most dominant fern in the coal beds.
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ceous remains (Muir, 1964; see Plate I, 2). However, the osmundaceous macroremains in Yorkshire were mainly found in £oodplain deposits, siltstones, clays, etc. (Van Konijnenburg-Van Cittert and Morgans, 1999). The Early and Middle Triassic fern Anomopteris mougeotii known from France and Italy has sporangial features that suggest a close relationship to the Osmundaceae, especially the living genus Todea and the fossil Todites. However, the presence of aphlebia at the pinna bases and a W-shaped vascular bundle do not occur in this family (Grauvogel-Stamm and Grauvogel, 1980). Anomopteris might have been adapted to living in ecologically unstable environments such as the borders of sedimentary basins (Grauvogel-Stamm and Grauvogel, 1980; personal observation in Anisian and Ladinian £oras in the Dolomites where volcanism was rather common and where large Anomopteris remains were found in close association with, e.g. fossil ¢sh, brachiopods, ammonites, etc.). 2.3. Schizaeaceae The ¢rst unequivocal occurrences of members of this family are in the Liassic (Stachypteris in China) or Middle Jurassic (Klukia all over the world; Plate I, 3). The a⁄nity of these genera lies with the living Lygodium rather than with Anemia, although the foliage does not resemble that of the former genus (Van Konijnenburg-
Plate I. 1.
2.
3.
4.
Pseudodanaeopsis sp.; U5.5. Detail of venation of this impression fossil. This plant may have been either a seedfern or possibly a mangrove fern comparable to the living Acrostichum. Note the dots between the vein meshes which indicate hair bases. Cladophlebis denticulata (Brongniart) Fontaine; U1. Part of a large sterile frond (compression). This species was often a coal former during the Jurassic. Klukia exilis (Philips) Raciborski; U1. Example of a Jurassic schizaeaceous fern (compression) that probably lived along riverbanks. Phlebopteris dunkeri (Schenk) Schenk; U2. This species is almost always preserved as fusain in the Late Jurassic £ora of Sutherland.
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Van Cittert, 1991). In the Early Cretaceous, the family became widespread with genera such as Ru¡ordia, Pelletixia and Schizaeopsis which are thought to be Anemia-like (Tidwell and Ash, 1994; Collinson, 1996) and members of the living genus Anemia have been recorded from strata of that age (e.g. Skog and Dilcher, 1994). As to the ecology of the Schizaeaceae, all these ferns probably preferred warm, humid environments as they were mainly recorded from sandstones and clays in the subtropical belt of the Northern Hemisphere (Vakhrameev, 1991). They may have grown along riverbanks or as understorey in forests (Dettmann and Cli¡ord, 1992; Skog and Dilcher, 1994; Watson and Alvin, 1996). Pelletixia had rather enclosed sori, perhaps comparable with the sporocarps of the water fern family Marsileaceae (Bierhorst, 1971). These sporocarps are highly resistant to desiccation and are known to retain viability over several years (Watson and Alvin, 1996). Crabtree (1988) suggested for the schizaeaceous ferns such as Anemia fremontii from the Mid-Cretaceous Albino member (MT, USA) an environment of swampy mud £ats or shallow, ephemeral lake beds situated on a delta adjacent to the mid-continental epeiric sea. So far, no record of coal-bearing strata with any of these fern genera is known. 2.4. Gleicheniaceae The family has been traced back to the Permian (Rothwell, 1996), although some of the older fossils, such as Oligocarpia and Sermeya, are now attributed to the fossil family Sermeyaceae (Tidwell and Ash, 1994; Collinson, 1996). Also there is some doubt about a de¢nite attribution to the family of some of the older fossils because they lack the pseudo-dichotomous branching pattern typical of the Gleicheniaceae. Living Gleicheniaceae often grow in open, sunny places but often with their rhizomes embedded in damp soil. In the tropics, they may cover vast, almost impregnable areas and are thus considered to be a very di⁄cult weed on agricultural ¢elds in those areas (Smith, 1955; Walker, 1994). The putative Permian and Triassic members of this family may well have lived under the ‘normal’
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humid, rather warm conditions that prevailed for most ferns. There is no evidence whatsoever that any of these fossils have lived under di¡erent circumstances. The Gleicheniaceae are not common in most Jurassic assemblages either, e.g. they are absent in the famous Yorkshire Jurassic £ora and only a few specimens of presumably Gleicheniaceous origin have been found in Iran. However, in the Late Jurassic £ora of Scotland Gleichenites cycadina is one of the most common fossils and it almost always occurs in rather small fragments of fusain (Plate II, 5). This latter occurrence probably represents ferns dwelling on upland areas that were often subject to ¢re (Van der Burgh and Van Konijnenburg-Van Cittert, 1984; Van Konijnenburg-Van Cittert and Van der Burgh, 1996). The same preservation has been reported for Gleichenites and Gleichenia species in the Wealden of England (Harris, 1981; Watson and Alvin, 1996). The Early Cretaceous species Gleichenia chaloneri might also have been living under stress (indicated by the presence of trichomes and sunken stomata ; Herendeen and Skog, 1998), but has also been preserved as fusain. The same applies to Late Cretaceous Boodlepteris-like material
Plate II. 1.
2.
3.
4.
5.
Dictyophyllum rugosum Lindley et Hutton; U0.5. Here associated with Todites williamsonii (Brongniart) Seward; both species (usually found as compressions which is the case here as well) are often preserved as large fronds, indicating probably a humid, subtropical climate. Hausmannia buchii Andrae; U2. This Hausmannia species is almost always preserved as fusain in the Late Jurassic £ora of Sutherland. Hausmannia dichotoma Dunker; U1. This Hausmannia species is never preserved as fusain in the Late Jurassic £ora of Sutherland but is a compression. Coniopteris simplex (Lindley et Hutton) Harris; U2. There is no indication that any Coniopteris species was a tree fern during the Jurassic. They are always found as smaller or larger frond fragments, either as impressions or as compressions. The latter is the case here. Gleichenites cycadina (Schenk) Seward; U1. This species is always preserved as fusain in the Late Jurassic £ora of Sutherland.
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(Gandolfo et al., 1997) and a Tertiary Gleichenia species from Australia (Blackburn and Sluiter, 1994). There the pinnules are often found charcoali¢ed whilst the scaly, woody rhizomes occupy laterally extensive beds. This fossil material is almost identical to the living G. dicarpa, a ¢re-tolerant species (Blackburn and Sluiter, 1994). However, Gleicheniaceous fossils from the Dakota Formation (Early Cretaceous, USA) occur as normal impressions and not as fusain. Skog and Dilcher (1994) suggested that these ferns grew in dense stands just as living Gleichenia, and that the tough fronds were transported over considerable distances before deposition. They might have been a major component of fern ‘savannahs or prairies’ according to Skog and Dilcher. Crabtree (1988) stated that especially gleicheniaceous ferns appear to be characteristic of various Mid-Cretaceous ash beds indicating that they were important components of an early successional (pioneer) vegetation. Cretaceous fern £oras from non-volcanic rocks typically lack gleicheniaceous ferns. 2.5. Matoniaceae This family, characterised by, e.g. a typical ‘pedal’ branching pattern for the fronds, was ¢rmly established from the Late Triassic onwards with members of the non-indusiate genus Phlebopteris, which then became widespread during the Jurassic. During the Jurassic more genera appeared, including members of the living genus Matonia with a well-developed indusium, Matonidium with a smaller indusium and Selenocarpus with non-indusiate crescent-shaped sori (Van Konijnenburg-Van Cittert, 1993; Tidwell and Ash, 1994; Collinson, 1996). In the Late Jurassic and Cretaceous bipinnate genera such as Piazopteris and Delosorus also appeared. The ecology of all these ferns can be quite variable ; some of the fronds must have been quite large and have certainly grown under humid conditions as understorey or along riverbanks. Examples of these are Selenocarpus muensterianus and Phlebopteris angustiloba in the Early Jurassic, P. polypodioides and P. tracyi in the Middle Jurassic (Ash, 1991; Philippe et al., 1998; personal observation). Others were more stress-adapted
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and the ecology of some ferns was quite variable even within one species. The most striking fern in this respect is Phlebopteris woodwardii. It is one of the peat generators in Romania (see Table 1) with beautifully preserved material that yielded in situ spores. In the Stones¢eld £ora (Bathonian, England; Seward, 1904), the species has been found as impression fragments and the fern probably grew along a riverbank. In the more or less contemporaneous Yorkshire Jurassic (where the type specimen originated; see Harris, 1961) and a £ora in northwest Scotland (Bateman et al., 2000), the species has been recorded only as fusain (charcoal), suggesting that P. woodwardii was an abundant plant of inland heaths which was only preserved in the delta as a result of burning and £ood. This situation would have been comparable to a modern English heath ¢re (Harris, 1981). A number of other Phlebopteris species were also preserved as fusain, e.g. P. dunkeri in the Late Jurassic of Scotland (Plate I, 4; Van Konijnenburg-Van Cittert and Van der Burgh, 1996) and Phlebopteris species in the English Wealden £ora (Harris, 1981; Watson and Alvin, 1996). Some members of the family were adapted to an arid climate in the Cretaceous. An example is the well-known Weichselia, which some authors classi¢ed into a separate family Weichseliaceae because of its reduced and well-protected sporangia (see Tidwell and Ash, 1994; Collinson, 1996). Weichselia remains especially have often been recorded as fusain (Harris, 1981; Vakhrameev, 1991; Watson and Alvin, 1996; Collinson et al., 1999). Another example is the genus Piazopteris that was growing in dry localities in tropical and subtropical areas during the Late Jurassic and Early Cretaceous. Both genera are absent from the warm^moderate zone of the Northern Hemisphere (sensu Vakhrameev, 1991). 2.6. Dipteridaceae This family, again with a typical frond-branching pattern resembling that of the Matoniaceae, is a very important one in the Mesozoic (especially Late Triassic and Jurassic), with many genera (e.g. Clathropteris, Dictyophyllum, Camptopteris,
Hausmannia, Kenderlykia, Goeppertella) all over the world (Tidwell and Ash, 1994; Collinson, 1996). The only extant genus, Dipteris, is restricted to the tropical Malaysian Archipelago similar to the living Matoniaceae. Extant Dipteris includes a species growing on streambanks where the canopy is open, and also species that are colonisers of disturbed sites and exposed ridges (Cantrill, 1995). During the Mesozoic the Dipteridaceae mainly occupied moist localities in the temperate^warm and subtropical zones. Some members of the family must have been quite large, e.g. some Dictyophyllum species judging by the long and stout petiole fragments (over 1 m long) and large frond remains that have been found (Plate II, 1; personal observation). According to Barale (1990) Dictyophyllum and Clathropteris migrated with the warm, humid climate from southeast Asia (Late Triassic) to southwestern Asia and Europe (Early Jurassic). During the Jurassic, some species, especially of Hausmannia, adapted to more stress-related environments. For example, Hausmannia dichotoma (Plate II, 3) might have occupied a brackish habitat in the Late Jurassic Sutherland £ora (Van Konijnenburg-Van Cittert and Van der Burgh, 1996), and Watson and Alvin (1996) record that this species had leathery leaves in the English Wealden. H. buchii has been recorded as fusain in the Sutherland £ora (Plate II, 2; Van Konijnenburg-Van Cittert and Van der Burgh, 1996), although it is also known as normal compressions in other Jurassic £oras (e.g. Popa, 2000). Rare fusain fragments of Hausmannia species were also recorded from Bathonian assemblages in Skye (northwest Scotland) by Bateman et al. (2000). Cantrill (1995) interpreted the Antarctic species Hausmannia papilio as a streamside dweller and coloniser of disturbed sites just like some extant Dipteris species. It is quite possible that, with the oncoming warming during the Cretaceous, members of the family could not adapt to these warmer and more arid circumstances. As a result they died out, except for the genus Hausmannia (the only genus recorded from the Cretaceous) which is indistinguishable from living Dipteris that survived in its refugium.
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2.7. Dicksoniaceae
2.8. Cyatheaceae
The Dicksoniaceae are sometimes included in the Cyatheaceae s.l. (e.g. Lovis, 1977), but other authors separate them on the basis of their marginal sori contrasting with the super¢cial sori in the Cyatheaceae s.s. (see Tidwell and Ash, 1994); this latter opinion is accepted here. The family ¢rst appeared in the Late Triassic and is especially abundant in the Jurassic and Early Cretaceous with leaf remains of many species, particularly of Coniopteris, all over the world. This genus, just as other fossil Mesozoic dicksoniaceous genera such as Eboracia, Kylikipteris and Dicksonia, has been recorded from clays, sandstones and siltstones, and the ferns probably preferred a warm, moist habitat (Plate II, 4) (Vakhrameev, 1991). Present-day Dicksoniaceae are tree ferns occurring in both tropical and temperate rain forests in the Southern Hemisphere. It is generally thought that the majority of the fossils were tree ferns as well and occupied more or less the same habitats as the living ones (Vakhrameev, 1991; Tidwell and Nishida, 1993). However, for at least the Late Triassic and the majority of the Jurassic fossils, there is no proof of this. The ¢rst possible tree fern stems that might be attributed to the Dicksoniaceae/Cyatheaceae (Cyatheaceae s.l.) date from the Late Jurassic (Tidwell and Nishida, 1993). There are more records in the Cretaceous, mainly from the USA (e.g. Tidwell and Nishida, 1993 from the Early Cretaceous of South Dakota; Lantz et al., 1999 from the Aptian of California ; Hilton et al., 1997 from the Late Cretaceous of California). Most of these fossils are stems that resemble living dicksoniaceous stems more closely than cyatheaceous stems. An exception in ecology may be the Late Jurassic^Early Cretaceous fern Onychiopsis psilotoides which reveals a remarkable protection of its sporangia as they are completely enclosed in thick-walled fertile bodies. Moreover, the sterile segments are coriaceous in texture and, therefore, this plant may have been adapted to high-stress environments at the margin of a more or less brackish bay (Friis and Pedersen, 1990).
The Cyatheaceae s.s. is a family of living tropical and subtropical tree ferns that is rather poorly represented by fossil remains. It is ¢rst recorded in the Jurassic from leaf remains in Poland (Alsophilites) and stems in Australia (Oguracaulis) (e.g. Tidwell and Ash, 1994; Collinson, 1996). Both stems and leaf remains are more common in the Cretaceous (e.g. Krassilov, 1978 from Mongolia), and the ¢rst record of sterile and fertile foliage attributed to the living genus Cyathea is from the Early Cretaceous of Patagonia (Villar de Seoane, 1999). It is thought that this family has not changed greatly morphologically and anatomically from that time to the present (Villar de Seoane, 1999). The same probably applies to the habitats where the plants lived. 2.9. Tempskyaceae This family is only known from large petri¢ed ‘false’ stems that actually consist of numerous single stems bound together by masses of adventitious roots (e.g. Tidwell and Ash, 1994; Collinson, 1996). These trunks have been reported mainly from Lower and Middle Cretaceous sediments in Laurasia. The associated fronds were described by Tidwell and Hebbert (1992) as thin and delicate when they reported the discovery of some trunks in the position of growth embedded in undisturbed carbonaceous shale. The presence of pyritic sulphur in the shale indicates a swampy habitat (Tidwell and Hebbert, 1992; Tidwell and Ash, 1994; Watson and Alvin, 1996). 2.10. Hymenophyllaceae There was no de¢nite Mesozoic record of the ‘¢lmy ferns’ until recently, when Deng (1997) described Eogonocormus cretaceum from the Early Cretaceous of northeast China. This thalloid fossil leaf resembles the Hepaticae, but detailed study of the leaf, sorus, sporangium and spore morphology revealed that this plant has to be attributed to the Hymenophyllaceae. Eogonocormus is a small fern with fronds only several centimetres high and a creeping rhizome bearing slender, hair-like roots.
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Many of the fronds were connected with the rhizomes, covering the surface of the mudstone in which the fossils were found. This suggests that they were fossilised more or less in situ, and that the fern, like its living relatives, probably grew in humid areas close to water. 2.11. Leptosporangiate ferns with vertical annuli Very few convincing ‘polypodiaceous’ ferns have been described from the earlier parts of the Mesozoic (Tidwell and Ash, 1994; Collinson, 1996), although many specimens have been assigned to this group in the past. One of the problems is the lack of diagnostic characters. The main character of the group is the leptosporangiate sporangium that has a vertical annulus and usually contains 64 spores. Furthermore, the sporangia in a sorus do not mature at the same time, a feature that is often di⁄cult to observe in fossil material. The earliest known representative so far is Aspidistes thomasii, ¢rst described from the Middle Jurassic of Yorkshire (Harris, 1961), with a tentative assignment to ?Aspideae. Lovis (1977) concluded that it might represent a member of the Thelypteridaceae. Based on re-examination of the type material, Collinson (1996) proposed that A. thomasii could best be treated as ?Thelypteridaceae. Two other species of Aspidistes (A. beckeri from the Jurassic of Israel and A. sewardii from the Cretaceous of England) most likely belong to the Matoniaceae (Lovis, 1977). There are more records of polypodiaceous fossils from the Early Cretaceous, e.g. members of the genera Australopteris (showing the vertical annulus and comparable to the living genus Drynaria) and Onoclea. The latter is especially poorly characterised (Tidwell and Ash, 1994). Deng (1995) summarised several polypodiaceous species from China, i.e. a species of Athyrium, one of Asplenium and two of Dryopteris. All fossils yielded the monolete spores typical of many Polypodiaceae and the sporangia demonstrated a vertical annulus as well. These ferns have mediumsized thin fronds usually found in coal-bearing sediments (mostly mudstones or siltstones), which led Deng (2002) suggest that the parent ferns lived
under warm, humid conditions close to a wetland depositional site. The only other Mesozoic member of this group is fertile fern foliage from the Early Cretaceous of Antarctica described by Cantrill (1998) as Lophosoria cupulatus. The foliage is morphologically similar to that of the form genus Gleichenites but has been assigned by him to the monospeci¢c fern family Lophosoriaceae. This assignment was based on the absence of the pseudo-dichotomous branching pattern (with a sleeping bud) typical for the living Gleicheniaceae, and on the presence of the distinctive spore morphology (cingulate with proximal contact faces having a raised foveolate pad) typical of the living Lophosoria. Moreover, the soral features also supported placement in the Lophosoriaceae. The living L. quadripinnata is an opportunist invading disturbed, open areas and the fossil L. cupulatus might have occupied a similar habitat (Cantrill, 1998).
3. Conclusions ^ The ecology of the majority of Mesozoic ferns con¢rms the common view that they grew under moist, rather warm conditions either in marshes, along riverbanks or as understorey in forests. This is especially true in the case of the Marattiaceae, Osmundaceae, Cyatheaceae, Tempskyaceae, Dipteridaceae, Dicksoniaceae and Schizaeaceae, although in the latter three families some mainly Cretaceous taxa may have been opportunists colonising disturbed ground after volcanic eruptions. ^ Ferns forming peat (resulting in coal) were common, especially in the Early Jurassic. However, the composition of these fern £oras was markedly di¡erent in various regions (see Table 1), although members of the Osmundaceae, Matoniaceae and Dipteridaceae were always present. Marattiaceous ferns partook in peat formation only in some areas, whilst members of other families played an unimportant role in the peat-forming process or have never been recorded from these £oras (e.g. Schizaeaceae, Gleicheniaceae). ^ Members of certain families, especially Matoniaceae (some Phlebopteris species and Weichse-
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lia) and Gleicheniaceae (Gleichenites), were able to adapt to the more stress-related semiarid and ¢re-prone conditions that developed since the Late Jurassic. Of course, this does not imply that all members of these families showed the same ecological adaptations. ^ In the genus Hausmannia of the Dipteridaceae, some species (e.g. H. dichotoma) developed an adaptation to brackish habitats, others (e.g. H. buchii) were recorded as fusain in some £oras but as compression fossils in other £oras. ^ Onychiopsis psilotoides from the Dicksoniaceae might also have been adapted to high-stress environments, judging from the coriaceous texture of its fronds and the remarkable protection of its sporangia. ^ Assuming correct taxonomic determinations, some taxa (e.g. Phlebopteris woodwardii, Hausmannia buchii) grew under di¡erent environmental circumstances at di¡erent times, or even during the same periods.
Acknowledgements I gratefully acknowledge the help of Dr. Maria Barbacka, Budapest, and Dr. Mihai Popa, Bucharest, who provided me with the data on Liassic coal formation in Hungary and Romania, respectively. Discussions with Dr. Margaret Collinson are very much appreciated. This paper benefited greatly from remarks and suggestions made by Dr. Sid Ash and Dr. Joan Watson. References Ash, S., 1991. A new Jurassic Phlebopteris (Plantae, Filicales) from the Wallowa Terrane in the Snake River Canyon, Oregon and Idaho. J. Paleontol. 65, 322^329. Barale, G., 1990. Les strate¤gies adaptives chez les ve¤ge¤taux du Trias supe¤rieur au Cre¤tace¤ infe¤rieur dans l’aire eurosinienne, en relation avec l’e¤volution du climat. C.R. Acad. Sci. Paris 311, Ser. II, 265^269. Bateman, R.M., Morton, N., Dower, B.L., 2000. Early Middle Jurassic plant communities in northwest Scotland: Paleoecological and Paleoclimatic signi¢cance. Geores. Forum 6, 501^512. Bierhorst, D.W., 1971. Morphology of Vascular Plants. Macmillan, New York, 500 pp.
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Blackburn, D.T., Sluiter, I.R.K., 1994. The Oligo^Miocene £oras of southeastern Australia. In: Hill, R.S. (Ed.), History of the Australian Vegetation: Cretaceous to Recent. Cambridge University Press, Cambridge, pp. 328^367. Cantrill, D.J., 1995. The occurrence of the fern Hausmannia Dunker (Dipteridaceae) in the Cretaceous of Alexander Island, Antarctica. Alcheringa 19, 243^254. Cantrill, D.J., 1998. Early Cretaceous fern foliage from President Head, Snow Island, Antarctica. Alcheringa 22, 241^ 258. Collinson, M.E., 1996. ‘What use are fossil ferns?’ ^ 20 years on: with a review of the fossil history of extant Pteridophyte families and genera. In: Camus, J.M., Gibby, M., Johns, R.J. (Eds.), Pteridology in Perspective. Royal Botanic Gardens, Kew, pp. 349^394. Collinson, M.E., Featherstone, C., Cripps, J.A., Nichols, G.J., Scott, A.C., 1999. Charcoal-rich plant debris accumulations in the Lower Cretaceous of the Isle of Wight, England. Acta Palaeobot. Suppl. 2, 93^105. Crabtree, D.R., 1988. Mid-Cretaceous ferns in situ from the Albino member of the Mowry Shale, southwestern Montana. Palaeontographica B 209, 1^27. Deng, S., 1995. New materials of the Early Cretaceous monolete spore ferns and their taxonomic study. Acta Bot. Sin. 37, 483^491. Deng, S., 1997. Eogonocormus ^ a new Early Cretaceous fern of Hymenophyllaceae from China. Aust. Syst. Bot. 10, 59^ 67. Deng, S., 2002. Ecology of the Early Cretaceous ferns of Northeast China. Rev. Palaeobot. Palynol. 119, 93^112. Dettmann, M.E., Cli¡ord, H.T., 1992. Phylogeny and biogeography of Ru¡ordia, Mohria and Anemia (Schizaeaceae) and Ceratopteris (Pteridaceae): evidence from in situ and dispersed spores. Alcheringa 16, 269^314. Dobruskina, I.A., 1994. Triassic Floras of Eurasia. Oesterr. Akad. Wiss. Schriftenr. Erdwiss. Komm. 10, 422 pp. Friis, E.M., Pedersen, K.R., 1990. Structure of the Lower Cretaceous fern Onychiopsis psilotoides from Bornholm, Denmark. Rev. Palaeobot. Palynol. 66, 47^63. Gandolfo, M.A., Nixon, K.C., Crepet, W.L., Ratcli¡e, G.E., 1997. A new fossil fern assignable to Gleicheniaceae from Late Cretaceous sediments of New Jersey. Am. J. Bot. 84, 483^493. Gnaccolini, M., Jadoul, F., 1988. Un sistema deposizionale delta^laguna^piattaforma carbonatica nel Carnico Lombardo (Triassico superiore, Alpi meridionali, Italia). Riv. Ital. Paleontol. Stratigr. 93, 447^468. Grauvogel-Stamm, L., Grauvogel, L., 1980. Morphologie et anatomie d’Anomopteris mougeoti Brongniart, une fouge're du Buntsandstein supe¤rieure des Vosges (France). Sci. Geol. Bull. 33, 53^66. Harris, T.M., 1961. The Yorkshire Jurassic Flora, I. Thallophyta^Pteridophyta. British Museum (Natural History), London, 212 pp. Harris, T.M., 1981. Burnt ferns from the English Wealden. Proc. Geol. Assoc. 92, 47^58. Herendeen, P.S., Skog, J., 1998. Gleichenia chaloneri ^ a new
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J.H.A. Van Konijnenburg-Van Cittert / Review of Palaeobotany and Palynology 119 (2002) 113^124
fossil fern from the Lower Cretaceous (Albian) of England. Int. J. Plant Sci. 159, 870^879. Hill, C.R., 1987. Jurassic Angiopteris (Marattiales) from North Yorkshire, UK. Rev. Palaeobot. Palynol. 51, 65^94. Hill, C.R., Camus, J.M., 1986. Evolutionary cladistics of marattialean ferns. Bull. Br. Mus. (Nat. Hist.) Bot. 14, 219^300. Hilton, R., Antuzzi, P., Arens, N.C., Erwin, D., 1997. A tree fern from the Late Cretaceous Chico Formation of Northern California. Geological Society of America, Boulder, CO, Abstr. Progr., p. A-97. Krassilov, V.A., 1978. Mesozoic lycopods and ferns from the Bureja Basin. Palaeontographica B 166, 16^29. Lantz, T.C., Rothwell, G.W., Stockey, R.A., 1999. Conantiopteris schuchmanii, gen. et sp. nov., and the role of fossils in resolving the phylogeny of Cyatheaceae s.l.. J. Plant Res. 112, 361^381. Lovis, J.D., 1977. Evolutionary patterns and process in ferns. Adv. Bot. Res. 4, 230^424. Muir, M.D., 1964. The Palaeoecology of the Small Spores of the Middle Jurassic of Yorkshire. Ph.D. Thesis, University of London (unpublished). Passoni, L., Van Konijnenburg-Van Cittert, J.H.A. submitted. New taxa of fossil Carnian plants from Mount Pora (Bergamasc Alps; Northern Italy) Rev. Palaeobot. Palynol.. Philippe, M., Thevenard, F., Barale, G., Ferry, S., Guignard, G., 1998. Middle Bathonian £oras and phytocoenoses of France. Palaeogeogr., Palaeoclimatol., Palaeoecol. 143, 135^158. Popa, M.E., 2000. Early Jurassic Land£ora of the Getic Nappe. Ph.D. Thesis, University of Bucharest (unpublished). Rothwell, G.W., 1996. Phylogenetic relationships of ferns: a palaeobotanical perspective. In: Camus, J.M., Gibby, M., Johns, R.J. (Eds.), Pteridology in Perspective. Royal Botanic Gardens, Kew, pp. 395^404. Seward, A.C., 1904. The Jurassic Flora, II. Liassic and Oolithic Floras of England. Catalogue of the Mesozoic Plants in the Department of Geology, British Museum (Natural History), London, 192 pp. Skog, J.E., Dilcher, D.L., 1994. Lower vascular plants of the Dakota Formation in Kansas and Nebraska, USA. Rev. Palaeobot. Palynol. 80, 1^18. Smith, G., 1955. Cryptogamic Botany, Vol. II. Bryophytes and Pteridophytes. McGraw-Hill, Tokyo, 399 pp. Thomas, B.A., 1985. Pteridophyte success and past biota ^ a palaeobotanist’s approach. Proc. R. Soc. Edinburgh 86B, 423^430.
Tidwell, W.D., Ash, S.R., 1994. A review of selected Triassic to Early Cretaceous ferns. J. Plant Res. 107, 417^442. Tidwell, W.D., Hebbert, N., 1992. Species of the Cretaceous tree fern Tempskya from Utah. Int. J. Plant Sci. 153, 513^ 528. Tidwell, W.D., Nishida, H., 1993. A new fossilized tree fern stem, Nishidacaulis burgii gen. et sp. nov., from Nebraska, South Dakota, USA. Rev. Palaeobot. Palynol. 78, 55^67. Vakhrameev, V.A., 1991. Jurassic and Cretaceous Floras and Climates of the Earth. Cambridge University Press, Cambridge, 318 pp. Van Cittert, J.H.A., 1966. Palaeobotany of the Mesophytic, II. New and noteworthy Jurassic ferns from Yorkshire. Acta Bot. Neerl. 15, 284^289. Van der Burgh, J., Van Konijnenburg-Van Cittert, J.H.A., 1984. A drifted £ora from the Kimmeridgian (Upper Jurassic) of Lothbeg Point, Sutherland, Scotland. Rev. Palaeobot. Palynol. 43, 359^396. Van Konijnenburg-Van Cittert, J.H.A., 1991. Diversi¢cation of spores in fossil and extant Schizaeaceae. In: Blackmore, S., Barnes, S.H. (Eds.), Pollen and Spores. Clarendon Press, Oxford, pp. 103^118. Van Konijnenburg-Van Cittert, J.H.A., 1993. A review of the Matoniaceae based on in situ spores. Rev. Palaeobot. Palynol. 78, 235^267. Van Konijnenburg-Van Cittert, J.H.A., Morgans, H.S., 1999. The Jurassic Flora of Yorkshire. Palaeontological Association Field Guides to Fossils 8, The Palaeontological Association, London, 134 pp. Van Konijnenburg-Van Cittert, J.H.A., Van der Burgh, J., 1996. Review of the Kimmeridgian £ora of Sutherland, Scotland, with reference to the ecology and in situ pollen and spores. Proc. Geol. Assoc. 107, 97^105. Van Konijnenburg-Van Cittert, J.H.A., Passoni, L., 1998. Carnian (Triassic) £ora from Mount Pora (Northern Italy). The 5th European Palaeobotanical and Palynological Conference, Cracow, Abstr. Vol., p. 189. Villar de Seoane, L., 1999. Estudio comparado de Cyathea cyathifolia comb. nov. del Cretacico inferior de patagonia, Argentina. Rev. Esp. Paleontol. 14, 157^163. Walker, L.R., 1994. E¡ects of fern thickets on woodland development on landslides in Puerto Rico. J. Veg. Sci. 5, 525^ 532. Watson, J., Alvin, K.L., 1996. An English Wealden £oral list, with comments on possible environmental indicators. Cretaceous Res. 17, 5^26.
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