Bollettino della Società Paleontologica Italiana, 51 (2), 2012, 71-84. Modena, 28 settembre 2012

The Jurassic plant fossils of the Lovisato Collection: preliminary notes Giovanni Giuseppe Scanu, Evelyn Kustatscher & Paola Pittau G.G. Scanu, Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, via Trentino 51, I-09127 Cagliari, Italy; [email protected] E. Kustatscher, Museo di Scienze Naturali dell’Alto Adige, via dei Bottai 1, I-39100 Bolzano, Italy; [email protected] P. Pittau, Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, via Trentino 51, I-09127 Cagliari, Italy; [email protected]

KEY WORDS - Palaeobotanical collection, Domenico Lovisato, Middle Jurassic, Sardinia, Museo Sardo di Geologia e Paleontologia “D. Lovisato”. ABSTRACT - A preliminary account is presented herein of the revision of 473 slabs containing macrofossil plant remains from the Domenico Lovisato plant Collection. The latter is housed in the Museo Sardo di Geologia e Paleontologia “D. Lovisato” of the Università di Cagliari. The material examined encompasses palaeobotanical remains collected from the Genna Selole Formation and from the basal part of the Dorgali Formation, both of Jurassic age at a variety of localities in Barbagia and Sarcidano, eastern Sardinia. A reconstruction is given of the history of the collection, initiated in 1888, and the scientific studies of the flora by a variety of palaeobotanists. Based on a preliminary revision of the specimens the following genera are recognized: Phlebopteris Brongniart, 1836, Hausmannia Dunker, 1846, Coniopteris Brongniart, 1849, Cladophlebis Brongniart, 1849, Sagenopteris Presl in Sternberg, 1838, Cycadeospermum Saporta, 1875, Ptilophyllum Morris in Grant, 1840, Williamsonia Carruthers, 1870 emend. Harris, 1969, Weltrichia Braun, 1847 emend. Harris, 1969, Taeniopteris Brongniart, 1828, Czekanowskia Heer, 1876 emend. Harris et al., 1974, Brachyphyllum Brongniart, 1828, Elatocladus Halle, 1913 emend. Harris, 1979 and Carpolithes Brongniart, 1822. Some plant remains have been putatively assigned to the following genera: Ptilozamites Nathorst, 1878 emend. Antevs, 1914, Nilssonia Brongniart, 1825, Pterophyllum Brongniart, 1828 and Geinitzia Endlicher, 1847. Several of these genera are known also from the Jurassic flora of Yorkshire and from other Jurassic floras of Italy. RIASSUNTO - [La flora giurassica della Collezione Lovisato: nota preliminare] - In questo lavoro vengono presentati i dati preliminari della revisione sistematica di 473 reperti contenenti resti macroscopici di piante fossili della Collezione Lovisato, conservata presso il Museo di Geologia e Paleontologia Domenico Lovisato, dell’Università degli Studi di Cagliari. La collezione comprende resti fossili raccolti in diverse località del Sarcidano e della Barbagia, nella Sardegna orientale, e provenienti dalla Formazione di Genna Selole e dalla porzione basale della Formazione di Dorgali, entrambe di età medio giurassica. Viene ricostruita la storia della collezione e degli studi effettuati su di essa dai vari studiosi che si sono succeduti nel tempo, a partire dal 1888, anno di inizio delle raccolte e dei campionamenti da parte del Prof. Domenico Lovisato. La revisione tassonomica preliminare consente di fornire una lista aggiornata a livello generico delle forme riconosciute nella collezione, che sono: Phlebopteris Brongniart, 1836, Hausmannia Dunker, 1846, Coniopteris Brongniart, 1849, Cladophlebis Brongniart, 1849, Sagenopteris Presl in Sternberg, 1838, Cycadeospermum Saporta, 1875, Ptilophyllum Morris in Grant, 1840, Williamsonia Carruthers, 1870 emend. Harris, 1969, Weltrichia Braun, 1847 emend. Harris, 1969, Taeniopteris Brongniart, 1828, Czekanowskia Heer, 1876 emend. Harris et al., 1974, Brachyphyllum Brongniart, 1828, Elatocladus Halle, 1913 emend. Harris, 1979 e Carpolithes Brongniart, 1822. Anche i generi Ptilozamites Nathorst, 1878 emend. Antevs, 1914, Nilssonia Brongniart, 1825, Pterophyllum Brongniart, 1828 e Geinitzia Endlicher, 1847 possono essere dubitativamente segnalati per questa flora. Un numero consistente di generi segnalati per il Giurassico della Sardegna sono noti sia nella flora giurassica dello Yorkshire (Inghilterra) sia nelle altre flore giurassiche del territorio italiano, come ad esempio presso la località di Rotzo, in Veneto.

INTRODUCTION The collection of the Sardinian Jurassic plant remains, housed at the Geological and Palaeontological Museum of Cagliari University (Sardinia, Italy), consists of several hundred specimens coming from fossiliferous levels distributed over a wide area (Fig. 1) representing lacustrine-fluvial to coastal transitional environments. From 1888 to 1916 Domenico Lovisato (Fig. 2), Professor of Mineralogy and Geology and Director of the Regio Museo Mineralogico e Geologico dell’Università di Cagliari, created a collection based on plant remains from several localities in the Sarcidano and Barbagia areas of central-eastern Sardinia; his original collection numbered about 1200 specimens. The collection was allocated in the Natural History section of the Regio Museo housed in the Belgrano Palace in Cagliari, property of the University. Bombings in the 2nd World War severely damaged the collections, that were transferred to a building in Ghilarza (province of Oristano) in 1946, some tens of kilometres ISSN 0375-7633

from Cagliari. In 1957 all the palaeontological and mineralogical collections returned to the University and were housed in the Dipartimento di Scienze Chimiche e Geologiche. During the fifties and sixties of the twentieth century, small additions were made to the original Lovisato Collection. From this collection, 473 slabs were chosen from those collected by Lovisato and Tornquist and specifically identified by Krasser (1912, 1913, 1920) and Edwards (1929). The aim of this study is to show the historical background of one of the most important Italian floras of the Jurassic and to give an overview on previous studies carried out on the historical collection of Lovisato and on other specimens collected from the same area. A brief, preliminary overview on the flora is given. Finally, this paper will show the high potential of this flora in order to gain a better picture of the Jurassic floras of Italy and of the palaeoenvironmental and palaeoclimatic reconstruction during this time period. doi:10.4435/BSPI.2012.9

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Fig. 1 - Schematic map of the Tacchi area with the locations of sampling: a) Dispensa Genna Selole; b) Fermata Cignoni; c) Nuraghe Sutta Corongiu (from Dieni & Massari, 1985 and Costamagna et al., 2007, modified).

LOVISATO’S PLANT COLLECTION Domenico Lovisato was born at Isola d’Istria (Izola, in Slovenian) in 1842 and came to Sardinia after he returned from the Patagonia and Tierra del Fuego expedition of the Società Geologica Italiana (1881-83), since the Austrian administration declared him politically inconvenient for his fervid Italian patriotic feeling. He gained the position as Professor of Geology and Mineralogy at the Regia Università di Cagliari where he died on February 1916 after a fruitful life spent for the geological research in the field. He was very interested in Sardinian geology, palaeontology and mineralogy and, together with Gennari (Botanist), added numerous collections of fossils and minerals to the Regio Museo dell’Università di Cagliari. Part of the collection will be discussed here. The materials collected by Lovisato and Tornquist and described by Tornquist, Krasser and Edwards (Tornquist,

1902, 1904a, b; Krasser, 1912, 1913, 1920; Edwards, 1929) comprise a set of about 1200 rock slabs and only 73 index cards of taxa (Fig. 3). The astonishing difference between the number of fossils and the small number of cards is due to their loss during the 2nd World War. The plant remains were kept in cardboard boxes and had been numbered. From 1960 onwards, Comaschi Caria created a new inventory list when she rearranged the whole museum collection after the war. Very recently, 293 slabs, stored at the the Lovisato Collection of the Museo Sardo di Geologia e Paleontologia “D. Lovisato” (MGPDL), have been numbered in accordance to their position in the ICCD General Catalogue (Central Institute of the Catalogue and the Documentation of the Italian Heritage Board). The name given in the original card often disagrees with the taxon name reported in the inventory list; some cards are annotated with titles of literature, and Lovisato’s or Krasser’s or Edwards’s remarks on the

G.G. Scanu et alii - Jurassic flora of Sardinia

Fig. 2 - Portrait of Professor Domenico Lovisato (1842-1916).

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Yuccites, Caulopteris and Pterophyllum (Lovisato, 1903). Sterzel suggested a Triassic age for this flora. Tornquist (1902), in his paper on the geology of Sardinia, identified Jurassic genera such as Ptilophyllum. In 1904 Tornquist studied specimens collected by Lovisato and, partly, by himself (Tornquist, 1904a, b). In these papers he identified Jurassic species such as Ptilophyllum (Williamsonia) pecten, Otozamites beani and Coniopteris cf. arguta and confirmed the Jurassic age. Few years later, Krasser (1912, 1913, 1920) studied the Lovisato Collection coming from Laconi’s sandstones and organic shales. He attributed many remains of male flowers and seeds to Cycadeospermum impressum based on the affinity to Williamsonia leckenbyi. New species, such as Cycadeospermum sardinicum, Cycadeospermum persica and Cycadeospermum lovisatoi were erected as well. The holotypes and paratypes of these species are indicated as stored at the University of Prague (Comaschi Caria, 1959) but are missing today (pers. comm., Jiří and Zlatko Kvaček, 2012). Edwards (1929) revised Krasser’s taxa and moved Krasser’s species Laconiella sardinica to Gristhorpia nathorsti, Cycadeospermum sardinicum to Araucarites sardinicum, Otozamites lovisatoi to O. veronensis and Cheirolepis setosa to Cryptomerites divaricatus. Sagenopteris goeppertiana was considered close to S. phillipsi and Podozamites lanceolatus to Eretmophyllum spp., also known from the Yorkshire flora (Edwards, 1929; Comaschi Caria, 1959). The revision of the whole

taxa with descriptions of the published and unpublished taxa (Fig. 3). PREVIOUS WORKS Meneghini (1857) was the first to note fossil plants from the Jurassic basin of central Sardinia that had been collected by Lamarmora, published and figured in the famous scientific diary “Voyage en Sardaigne” (Lamarmora, 1857). Meneghini kept in Pisa the studied material that was collected at Laconi and at San Antonio near Nuraghe Adòni (Sarcidano area) and near Tonara (Barbagia). He reported the presence of Brachyphyllum majus and Calamites lehmannianus. The flora was considered of Jurassic age. In a short note De Stefani (1891), Director of the Regio Museo di Fisica e Storia Naturale di Firenze, reported conifers (Voltzia sp.) and Equisetales (Equisetum cf. arenaceum) at the base of the dolomitic massifs at Tonara and Laconi, central Sardinia. This taxonomic interpretation led him to attribute the basal fluvial conglomerate with flora remains to the Triassic, analogous to the “Muschelsandstein” of Vosges. Lovisato never published the material collected by him, but many preliminary descriptions, with new species as well, were written by him in small cards added to the samples (Fig. 3). In 1902 Lovisato sent samples, collected in the Sarcidano area, to Sterzel in Chemnitz, who indicated the following genera for the flora: Albertia, Calamites,

Fig. 3 - Selection of some original taxa index cards (from the Historical Archive of the Museo Sardo di Geologia e Paleontologia “D. Lovisato”).

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genus Laccopteris (junior synonym of Phlebopteris) led the author to confirm the presence of L. polypoidioides and L. woodwardii. Finally, Comaschi Caria (1959) gave an overview on the Lovisato’s Collection and published a list of all fossil plants coming from Jurassic sediments of Sardinia. She indicated also several taxa from a new outcrop near Laconi (Nuraghe Enna): Chladophlebis denticulata, Equisetum arenaceum, Pachyphyllum araucarinum, Ptilophyllum (Williamsonia) pecten and Taeniopteris vittata. In the 60s, Prof. Charrier revised a very small part of the Lovisato Collection, studying only the specimens shown at the museum. He did not publish the systematic revision, but annotated the revised names on the small index taxa cards. The latest findings are reported in Dieni et al. (1983) in a paper on the Genna Selole Formation at Baunei (Ogliastra Province), where only Ptilophyllum hirsutum and Nilssonia orientalis are mentioned. For a detailed list of the species indicated by the various authors, see Tab. 1. Del Rio (1976, 1984) studied the palynomorphs revealing a higher number of taxa than recognized in the macro-remains. The general picture of the microflora corresponds to a Middle Jurassic flora developed in alluvial plains and coastal environments.

1. massive quartz conglomerate and stratified sandstone lenses representing deposits of distal alluvial fans and braided rivers are spread in the Laconi-Gadoni territories; 2. well-stratified fine sandstone, clayey siltites with organic shales and coal are very productive in plant remains. This facies crops out all over the surroundings of Nurri-Escalaplano territories and is the expression of alluvial, palustrine and upper delta plain sedimentation; 3. well stratified sandstones alternating with marls and marly limestones with thin wood coal beds yielding a lagoonal brackish and marine fauna including bivalves, brachiopods, gastropods, ostracods, foraminifers, charophytes and echinoderms. These facies develop from Ussassai - Perdasfogu - Baunei up to Tavolara representing deposits of littoral and deltaic setting, transitional to the marine Dorgali Formation. Its major development is to the south, in the Sarcidano area (Laconi and Nurallao plant fossiliferous sites) where it reaches a maximum thickness of 50 m. The conglomerate and sandstone of the Genna Selole Formation are of industrial interest; thus, quarries offer good sections to collect fossil plant remains. The fossil plant remains of the Lovisato Collection come from several quarries and natural sections at the base

GEOLOGY AND STRATIGRAPHY: BRIEF NOTES The Genna Selole Formation in the Tacchi area (Fig. 1) ranges from 5 to 50 m and contains the most abundant plant fossils found in Sardinia, where the entire Jurassic System can reach about 1000 m of thickness. During the Middle Jurassic (Bathonian) extensive areas in eastern Sardinia were subjected to a marine transgression that covered a thin succession of continental and transitional deposits (Genna Selole Formation), unconformably lying over the folded and flattened Palaeozoic Basement (Fig. 4). The Genna Selole Formation is continental at the base and evolves towards transitional and coastal sediments upwards. It starts with alluvial fan deposits consisting of conglomerates made of Permian volcanites and other Palaeozoic rocks; then, fluvial conglomerates mainly built by well-rounded quartz pebbles deriving from the erosion of the Palaeozoic phyllitic basement follow. These likely represent deposits of the middle and distal portion of alluvial fans (Dieni et al., 1983). The quartz sandstones and mudstones with grey and black pelitic layers are rich in macro-remains such as leaves, seeds, fructifications, small amber drops, and micro-remains like pollen grains, spores and foraminiferal linings. These sediments are interpreted as abandoned channels or temporary ponds (Dieni et al., 1983). The following transitional sediments are lagoonal tidallyinfluenced and include layers rich in brackish-water molluscs. The sandy-marly oolitic limestones of the basal Dorgali Formation with interlayered thick layers of black organic shales also hold abundant plant remains. The continental succession is overlain by a marine oolitic limestone of the Dorgali Formation that ranges 200-300 m in thickness (Fig. 4). The succession is laterally discontinuous and overall, in the area, three lithofacies-types are recognized (Costamagna et al., 2007):

Fig. 4 - Schematic representation of the Genna Selole Fm. and the basal part of the Dorgali Fm. (not in scale). Explanation of the legend: 1: Hercynian basement; 2: conglomerates; 3: pebbly sandstones; 4: sandstones; 5: pelites; 6: marly limestones; 7: limestones; 8: sandy oolitic dolostones; 9: oolitic dolostones; 10: dolostones; 11: seeds; 12: ferns and pteridosperms; 13: cycadophytes; 14: ginkgoes and conifers; 15: molluscs; 16: bioturbations.

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G.G. Scanu et alii - Jurassic flora of Sardinia TAXA

Tornquist (1902, 1904b) Krasser (1912, 1913, 1920) Edwards (1929) Comaschi Caria (1959)

Albertia brauni Schimper, 1837

x

Albertia latifolia Schimper, 1837

x

Araucarites sardinicus (Krasser) Krasser, 1920

x

x

x

Baiera phillipsi Nathorst, 1880

x

x

x

x

x

x

x

Brachyphyllum expansum (Presl in Sternberg) Seward emend. Kendall, 1949 Brachyphyllum mammillare Brongniart, 1828

x

Calamites cistii Brongniart, 1828 Calamites sp.

x x

Carpolithes sp. Caulopteris sp.

x x

Cladophlebis denticulata (Brongniart) Fontaine, 1889 Coniopteris arguta (Lindley et Hutton) Seward, 1900

cf.

Coniopteris hymenophylloides (Brongniart) Seward emend. Harris, 1961

x x

x

x

x

x

cf.

x

x

x

x

x

Cryptomerites divaricatus Bunbury, 1851 Cycadeospermum impressum Nathorst, 1879

x

Cycadeospermum lovisatoi Krasser, 1912

x

Cycadeospermum persica Krasser, 1912

x

Cycadeospermum sardinicum Krasser, 1912

x

Czekanowskia murrayana (Lindley et Hutton) Seward, 1900

x

Dadoxilon sp.

x

x x

x

x

x

x

Dictyophyllum rugosum Lindley et Hutton, 1831

x

x

x

Equisetites columnaris Brongniart, 1928

x

x

x

Equisetum arenaceum (Jaeger) Schenk, 1864

x

Equisetum mougeoti Brongniart, 1928

x

x x

Eretmophyllum lovisatoi Edwards, 1929

x

x

Gristhorpia nathorsti Thomas, 1925

x

x

Klukia exilis (Phillips) Raciborski, 1890

x

x

x

Laccopteris woodwardi (Leckenby) Seward, 1899

x

x

x

Nageiopsis anglica Seward, 1900

x

x

x

x

x

Neocalamites lehmanianus Goeppert, 1836

x

Nilssonia compta Brongniart, 1828

x

Nilssonia orientalis Heer, 1878 Otozamites beani (Lindley et Hutton) Brongniart, 1849

x x

Otozamites lovisatoi Krasser, 1913

x

x

x

Otozamites veronensis Zigno, 1881

x

Pachyohyllum araucarinum (Pomel) Saporta, 1870

x x

Pagiophyllum williamsoni Brongniart, 1828

x

Phlebopteris polypoidioides Brongniart, 1836 Pterophyllum cf. braunianum Goeppert, 1844

x

x

x

x

x

Ptilophyllum hirsutum Thomas et Bancroft, 1913

x

Ptilophyllum pecten (Phillips) Morris, 1841

x

x

Sagenopteris goeppertiana Zigno, 1885

x

x

Sagenopteris phillipsii (Brongniart) Presl in Sternberg, 1838

x

Sagenopteris rhoifolia Presl, 1838 var. elongata Braun

x x

Taeniopteris sp.

x

Taeniopteris vittata Brongniart, 1831

x

Thuites expansus Sternberg, 1823

x

Todites williamsoni (Brogniart) Seward emend. Harris, 1961

x

x

x

x

x x

x

x x

Williamsonia leckenbyi Nathorst, 1911

x

Williamsonia pecten Phillips, 1829

x

Williamsonia sewardi Krasser, 1913

x

Williamsonia whitbiensis Nathorst, 1911

x

x x

x

x

x x

Yuccites dubius Schimper et Mougeot, 1844 Zamites sp.

x x

Williamsonia acuminata (Zigno) Krasser, 1920

Yuccites vogesiacus Schimper et Mougeot, 1844

x x

Sardoa robitschekii Krasser, 1920

Voltzia sp.

Dieni et al. (1983)

x x

x x

x

x

Tab. 1 - Summary of the taxa list of the Jurassic Sardinian flora, as enlisted in the historical papers (Tornquist, 1902, 1904b; Krasser, 1912, 1913, 1920; Edwards, 1929; Comaschi Caria, 1959; Dieni et al., 1983).

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of the dolomitic massifs of central Sardinia, Barbagia and Sarcidano. Quarries for the extraction of quartz are located in the surroundings of the villages of Laconi, Nurri, Belvì and Nurallao (Fig. 1) and the natural sections crop out in the same area. They belong to the same basin and are accounted in the following localities: Dispensa Genna Selole, Fermata Cignoni, Nuraghe Sutta Corongiu (Fig. 1). PRESERVATION OF THE FOSSILS The plant fossils are preserved in different ways according to the environments in which they have been buried. Compressions and impressions are the most common preservation types. The compression fossils are in most cases represented by leaves with cuticles and are usually associated with fine-grained sediments such as silt, clay and marl, and/or with organic deposits like peat or coal. Mostly the seed ferns, cycadophytes and conifers yield well preserved cuticles for most species. Impressions are found frequently in the fine-grained rock matrix where remarkable details of the original form are preserved. Occasionally, impressions are also the counterparts of compression fossils containing the organic material when rock slabs are split apart. Sometimes the impressions are preserved in dirty coarsegrain sandstones mixed with silt and clay. In this case, the rock slab is generally not well consolidated and is formed in river and floodplain environments. The organic material is not preserved and has been replaced by a clay film that retains a detailed impression of the plant part. Dirty sand impressions are often record of leaves, shoots, fructifications and seeds. Compression and impression fossil plants, preserved in fine-grained and organic sediments, are found in the middle and upper part of the Genna Selole Formation and in the basal Dorgali Formation, whereas impression fossils in coarse grained-sediments are recorded in the basal continental lithofacies (Fig. 4). THE FLORA OF THE LOVISATO COLLECTION A systematic revision of the Jurassic plants of the Lovisato Collection is actually in progress. An updated list of the flora of the Lovisato Collection consists of 18 genera belonging to 7 divisions. The collection is dominated by

well-preserved cycadophytes. Conifers, ginkgophytes and ferns are abundant, while horsetails and seed ferns are rare. The sphenophytes (Pl. 1, fig. 1) are documented by some fragmentary stem impressions with distinct vascular bundles and nodes. The specimens have been attributed to the order Equisetales but due to the bad preservation of these remains, no attribution on generic level has been possible. Fern fragments have been attributed to the genera Phlebopteris Brongniart, 1836 (Pl. 1, fig. 2), Cladophlebis Brongniart, 1849 (Pl. 1, figs 3, 6), Hausmannia Dunker, 1846 (Pl. 1, fig. 4) and Coniopteris Brongniart, 1849 (Pl. 1, fig. 5). Some frond fragments with a basal dichotomy belong to the genus Phlebopteris. The pinnules are narrow and totally or broadly attached to the rachis. This genus has already been reported from Jurassic sediments with two species, Laccopteris (=Phlebopteris) polypoidioides and L. (=Phlebopteris) woodwardii (Edwards, 1929). The Cladophlebis fronds are bipinnate with smooth-edged pinnules. The veins extend for 2/3 of the lamina. One additional frond fragment has bigger pinnae and shows a very distinct midvein; unfortunately the secondary veins are too badly preserved to say if this specimen belongs to the genus Cladophlebis or perhaps to the genus Dictyophyllum. Krasser (1920), Edwards (1929) and Comaschi Caria (1959) enlisted already the genus Cladophlebis from the Jurassic of Sardinia. A specimen has been attributed to the genus Hausmannia. It shows a wedge-shaped structure with marked midribs. From the midrib secondary veins arise and form rectangular or square meshes measuring about 2 x 2 mm. At least two types of Coniopteris have been identified in the flora, with sterile and fertile pinnules. One frond type shows elongated, narrow pinnules, in the other one the pinnules are broad and with a rounded apex. The fertile fronds show terminal sporangia. Krasser (1920) reported C. hymenophylloides (Brongniart) Seward, 1900 emend. Harris, 1961 and C. cf. arguta (Lindley et Hutton) Seward, 1900 from the Jurassic flora of Sardinia, whereas Edwards (1929) indicated only C. hymenophylloides. One of the two frond types observed might indeed belong to C. hymenophylloides (Pl. 1, fig. 5) but only a detailed study will enable us to understand to which species the second sterile and type of fertile pinnae fragments belongs. Two different types of seed ferns have been identified as well, Sagenopteris Presl in Sternberg, 1838 (Pl. 1, fig. 7) and perhaps Ptilozamites Nathorst, 1878 emend.

EXPLANATION OF PLATE 1 Horsetails, ferns and seed ferns from the Jurassic of Sardinia. Fig. 1 - Sphenophyta indet. (NI - MGPDL 9350).

Fig. 5 - Coniopteris sp. (NI - MGPDL 9032).

Fig. 2 - Phlebopteris sp. (NI - MGPDL 9415).

Fig. 6 - Cladophlebis sp. (NI - MGPDL 9418).

Fig. 3 - Cladophlebis sp. (NI - MGPDL 9211).

Fig. 7 - Sagenopteris sp. (NI - MGPDL 9425).

Fig. 4 - Hausmannia sp. (NI - MGPDL 9415). Scale bar = 10 mm

G.G. Scanu et alii - Jurassic flora of Sardinia

Pl.77 1

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Antevs, 1914 (Pl. 2, fig. 1). Sagenopteris is characterized in leaflets with a marked midrib, although the preservation of the fragments does often not enable us to see the midrib clearly. Comaschi Caria (1959) enlisted two species for the Jurassic of Sardinia, S. goeppertiana De Zigno, 1885 and S. rhoifolia var. elongata Presl in Sternberg, 1838. Two leaf fragments show rhombic to slightly falcate segments inserted laterally to the rachis. The veins arise from the axis to the apex without forking. These specimens could be attributed to the seed fern Ptilozamites because of the thick cuticle with isodiametric cells or even to the bennettitalean leaf genus Anomozamites Schimper, 1870. Both genera have never been reported in Sardinia before. At least seven genera of cycadophytes have been distinguished in the collection. Several segment fragments with parallel, undivided secondary veins might belong to the genus Nilssonia Brongniart, 1825 (Pl. 2, fig. 6). Only cuticle analyses will permit a more detailed attribution. The leaves attributed putatively to the genus Pterophyllum Brongniart, 1828 show elongated segments with parallel veins and slightly expanded bases. The segments arise on the side of the rachis at almost right angle (Pl. 2, fig. 2). In the genus Ptilophyllum Morris in Grant, 1840 (Pl. 2, fig. 3) the segments are attached to the upper surface of the rachis at an angle of 55-80°; the venation frequency is about 9-12 per segment. Tornquist (1904b), Krasser (1920) and Comaschi Caria (1959) enlisted Ptilophyllum pecten (Phillips) Seward, 1904 from the Jurassic of Sardinia; a detailed cuticular analysis will be necessary to confirm this attribution. One leaf fragment can be assigned to Taeniopteris Brongniart, 1828 (Pl. 2, fig. 4). The entire-margined leaf shows a typical taeniopterid venation arising from the thick midrib. Unfortunately the margin is not preserved. Fructifications belonging to the cycadophytes have been identified as well. Impression

fossils with a round-oval shape and a scale-like structure have been attributed to Cycadeospermum Saporta, 1875 (Pl. 2, fig. 7); sometimes also small fragments of organic material have been preserved. Krasser (1912) described three different species from the Jurassic of Sardinia: Cycadeospermum sardinicum, Cycadeospermum persica and Cycadeospermum lovisatoi. So far we could not identify different forms in this group. The genus Williamsonia Carruthers, 1870 emend. Harris, 1969 (Pl. 2, fig. 8) includes bennettitalean female fructifications with a gynoecium with a minutely reticulated surface surrounded by interseminal scales (Pl. 2, figs 5-8). Krasser (1912, 1913, 1920), Edwards (1929) and Comaschi Caria (1959) described Williamsonia leckenbyi Nathorst, 1880 from the Jurassic of Sardinia. Some cup-like structures with extensive lobes can be attributed to the genus Weltrichia Braun, 1847 emend. Harris, 1969 (Pl. 3, fig. 1). As already indicated by Krasser (1913), some leaf fragments attributed to Czekanowskia Heer, 1876 emend. Harris et al., 1974 (Pl. 3, fig. 2) have also been identified in the flora. These elongated and linear leaves are sometimes dichotomously divided, but not more than one dichotomy has been observed in each segment, so far. Conifers are well represented in the flora, with at least three different genera. In Brachyphyllum Brongniart, 1828 (Pl. 3, fig. 3) the leaves are generally wider than long and helically arranged. The shoots with larger leaves (1.5-2 x 1.2 x 1.5 mm) could belong to Brachyphyllum mamillare Brongniart, 1828 enlisted already by Krasser (1913, 1920), Edwards (1929) and Comaschi Caria (1959). Only cuticular analyses can confirm this attribution as well as the presence of a second species, Brachyphyllum expansum (Sternberg) Seward, 1919 in the Jurassic of Sardinia. Shoot fragments with elongated, falcate leaves with an acute apex (up to 5 mm long and 1 mm wide)

EXPLANATION OF PLATE 2 Seed ferns and cycadophytes from the Jurassic of Sardinia. Fig. 1 - ?Ptilozamites sp. (NI - MGPDL 9328).

Fig. 5 - Williamsonia sp. (NI - MGPDL 9223).

Fig. 2 - ?Pterophyllum sp. (NI - MGPDL 9430).

Fig. 6 - ?Nilssonia sp. (NI - MGPDL 9349).

Fig. 3 - Ptilophyllum sp. (NI - MGPDL 246).

Fig. 7 - Cycadeospermum sp. (NI - MGPDL 9050).

Fig. 4 - Taeniopteris sp. (NI - MGPDL 9334).

Fig. 8 - Williamsonia sp. (NI - MGPDL 9419).

Scale bar = 10 mm

EXPLANATION OF PLATE 3 Cycadophytes, ginkgophytes and conifers from the Jurassic of Sardinia. Fig. 1 - Weltrichia sp. (NI - MGPDL 9345).

Fig. 4 - ?Geinitzia sp. (NI - MGPDL 9416).

Fig. 2 - Czekanowskia sp. (NI - MGPDL 9274).

Fig. 5 - Elatocladus sp. (NI - MGPDL 9373).

Fig. 3 - Brachyphyllum sp. (NI - MGPDL 9375).

Fig. 6 - Carpolithes sp. (NI - MGPDL 9442).

Scale bar = 10 mm

G.G. Scanu et alii - Jurassic flora of Sardinia

Pl.79 2

80 Pl. 3

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G.G. Scanu et alii - Jurassic flora of Sardinia TAXA

Yorkshire (Van Konijnenburg-van Cittert & Morgans, 1999)

Androstrobus Schimper, 1870

x

Angiopteris Hoffmann, 1796

x

Anomozamites Schimper, 1870

x

Araucarites Presl in Sternberg, 1838

x

Aspidistes Harris ,1961

x

Baiera Braun, 1843

x

Bilsdalea Harris, 1952

x

Brachyphyllum Brongniart, 1828

x

Rotzo (Wesley, 1966)

Roverè di Velo (Bartiromo & Barone Lumaga, 2009)

Lovisato’s Collection (this paper)

x

x

x

Carpolithes Brongniart, 1822

x

Caytonia Thomas,1925

x

Cladophlebis Brongniart, 1849

x

Coniopteris Brongniart, 1849

x

Ctenis Lindley et Hutton, 1834

x

Ctenozamites Nathorst, 1886

x

x x

x

Cycadeospermum Saporta, 1874

x

Cycadolepis Saporta, 1873

x

Cycadopteris Schimper, 1869

x

Cyparissidium Heer, 1874

x

Czekanowskia Heer, 1876

x

Dactylethrophyllum Wesley, 1956 Deltolepis Harris, 1942

x

x x

x x

x

Desmiophyllum Lesquereux, 1878

x

Dichopteris de Zigno, 1864

x

Dicksonia L’Héritier, 1789

x

x

Dictyophyllum Lindley et Hutton, 1834

x

x

Eboracia Thomas, 1911

x

Elatocladus Halle, 1913

x

Equisetites Sternberg, 1833

x

x

x

Equisetum Linnaeus, 1753

x

Eretmophyllum Thomas, 1913

x

Geinitzia Endlicher, 1847

x

Ginkgo Linnaeus, 1771

x

Gleichenites Bolchovitina, 1959

? x

Hausmannia Dunker, 1846

x

Hepaticites Walton, 1925

x

Hirmeriella Hörhammer, 1933

x

Hymenophyllites Göppert, 1836

x

Klukia Raciborski, 1890

x

Leptostrobus Heer, 1876

x

Lindleycladus Harris, 1979

x

Lomatopteris Schimper, 1879

x

Marattia Presl, 1845

x

Marskea Florin, 1958

x

Marzaria de Zigno, 1867

x

Matonia Stephenson et Churchill, 1831

x

Nilssonia Brongniart, 1825

x

Nilssoniopteris Nathorst, 1909

x

Osmundopsis Harris, 1931

x

Otozamites Braun in Münster, 1843

x

Pachypteris Karelin et Kirilow, 1842

x

Pagiophyllum Heer, 1881

x

Paracycas Harris, 1964

x

Phlebopteris Brongniart, 1837

x

Phyllotheca Brongniart, 1828 Pityanthus (Nathorst) Seward, 1919

x

x

x

x

x

x x x

Pseudosagenopteris Potonié, 1900 Pteroma Harris, 1964

x

x

Protorhipis Andrae, 1855 Pseudoctenis Seward, 1911

?

x x

Tab. 2 - Comparison at generic level of the Jurassic floras from Veneto (after Wesley, 1966; Bartiromo & Barone Lumaga, 2009), Sardinia (this paper) and Yorkshire (after Van Konijnenburg-van Cittert & Morgans, 1999).

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Pterophyllum Brongniart, 1825

x

x

Ptilophyllum Morris in Grant, 1840

x

x

? x

Ptilozamites Nathorst, 1878 Sagenopteris Presl in Sternberg, 1838

x

Scarburgia Harris, 1979

x

Solenites Lindley et Hutton, 1834

x

Sphenobaiera Florin, 1936

x

Sphenozamites (Brongniart) Miquel, 1851 Stenopteris Saporta, 1872

x

x

x

x x

Taeniopteris Brongniart, 1828

x

Todites Seward, 1900

x

Weltrichia Braun, 1847 emend. Harris, 1969

x

Williamsonia Carruthers, 1870

x

Yuccites Schimper et Mougeot, 1844 Zamites Brongniart, 1828

x ?

x x x

x

Tab. 2 - continue

could belong to the genus Geinitzia Endlicher, 1847 (Pl. 3, fig. 4). The shoot fragments of Elatocladus Halle, 1913 emend. Harris, 1979 (Pl. 3, fig. 5) are characterized by elongated leaves (4 x 1.3 mm) arranged in a large spiral. Additionally various seeds, putatively attributed to the genus Carpolithes Brongniart, 1822 (Pl. 3, fig. 6), occur in the sediments. THE FLORA OF SARDINIA AND OTHER EUROPEAN AND ITALIAN FLORAS The Early and Middle Jurassic floras, owing to their close inter-relations, share the same set of plant communities over a wide geographical area (Vakhrameev, 1964, 1991). From England in the west, France and Sardinia in the south, throughout the Germanic Basin, Poland, western Ukraine and the Volgi area, Donbas, the southern Urals (Vakhrameev, 1991) and Romania (Dragastan & Barbulescu, 1977-78; Popa & Van Konijnenburg-van Cittert, 2006) the fossil floras share a high number of genera in common with the flora of Yorkshire (Harris, 1961, 1964, 1969, 1979; Harris et al., 1974; Van Konijnenburg-van Cittert & Morgans, 1999) and differences are mainly at a specific level (Vakhrameev, 1991). A first comparison between the Jurassic flora of Sardinia and Yorkshire was done by Krasser (1920). The author showed a close relationship between the two floras concluding that of the 37 taxa from the Jurassic of Sardinia, 23 were in common with the Yorkshire Jurassic flora and only seven “endemic” from Sardinia, such as Otozamites lovisatoi Krasser, 1913, Zamites sp., Laconiella sardinica Krasser, 1920, Cycadeospermum lovisatoi Krasser, 1912, Cycadeospermum persica Krasser, 1912, Araucarites sardinicus (Krasser) Krasser, 1920 and Sardoa robitschekii Krasser, 1920 (Comaschi Caria, 1959). Krasser (1920) considered Sagenopteris goeppertiana Zigno, 1885 and Williamsonia acuminata (Zigno) Krasser, 1920, ancestral forms of the flora of the Oolites of the Veneto Alps and the genus Otozamites characteristic for the Jurassic flora of Yorkshire, France and of northern Italy.

In 1929, Edwards revised Krasser’s work and discussed the strong resemblance with the plant remains from England (21 out of 31 taxa). Edwards indicated also that on a generic level, Sardoa is the only taxon lacking in both floras. This preliminary study makes a new comparison at generic level between the floras of Yorkshire, Rotzo and Roverè di Velo, the latter two from northern Italy, necessary (Tab. 2). The Yorkshire Jurassic flora is one of the classic and most abundant Jurassic floras in the world. Fossil plants buried in Yorkshire sediments have been studied for example by Harris (1961, 1964, 1969, 1979), Harris et al. (1974), Van Konijnenburg-van Cittert & Morgans (1999) and Cleal et al. (2001) since the early XX century. Comparing this flora with the Sardinian one, ten genera have been found in common in both floras after the first preliminary revision: Brachyphyllum, Cladophlebis, Coniopteris, Czekanowskia, Elatocladus, Phlebopteris, Ptilophyllum, Sagenopteris, Weltrichia and Williamsonia. Only a detailed study will enable us to understand if the doubtful genera (indicated with the “?” in Tab. 2) are present in the Lovisato Collection or not. These taxa are: Geinitzia, Nilssonia, Pterophyllum and Ptilozamites. The historical flora from the Oolite limestone of Rotzo is the most famous flora from Italy. It has been studied mostly in the 19th century and became famous after the studies by De Zigno (1856-67, 1873-85). Later, Grandori (1913), Wesley (1956, 1958, 1966, 1974), Barale (1982) and Thévenard et al. (2005), revised partially the flora, with special interest in the bennettitaleans and pteridosperms. Additionally, the historical collection from Roverè di Velo, housed at the Museo di Paleontologia of the Università di Napoli “Federico II” , has recently been revised (Bartiromo & Barone Lumaga, 2009). The comparison of the Sardinian flora with the combined list of the revised flora of Wesley (1966) and Bartiromo & Barone Lumaga (2009) shows differences in the floral compositions that could be due to different growing conditions and environmental features. Conifers with scale-like leaves such as Brachyphyllum or falcate leaves (Pagiophyllum) dominated the Venetian Alps flora but are rare elements in Sardinia. Bennettitales of

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the Southern Alps account Otozamites and Ptilophyllum and the seed fern genera Cycadopteris, Dichopteris and Sagenopteris. Only Ptilophyllum and Sagenopteris have been found also in the Sardinian flora. Ferns and horsetails are rare in the Rotzo flora (Wesley, 1966); equisetales remains are also rare in the Sardinian flora but the ferns are common. Whether the difference between these two floras are based on climatic or evolutionary changes can be explained only after a throughout taxonomic study. CONCLUSIONS The 473 slabs with fossil plant remains from the Lovisato Collection, housed at the Geological and Palaeontological Museum of Cagliari University, represent an important historical collection of Jurassic age, which has been studied in the past by Italian geologists (Meneghini, 1857; De Stefani, 1891) but attracted the interest also from outstanding palaeobotanists such as Sterzel, Tornquist, Krasser and Edwards. A reorganisation of the palaeobotanical collection of the Palaeontological Museum showed that this flora needs, however, an extensive study using also cuticle analyses, which were done previously only partially by Edwards (1929). The preliminary study evidenced that some of the genera identified in literature cannot be confirmed for the collection such as for example Calamites Brongniart, 1828, Equisetites Sternberg, 1833, Klukia Raciborski, 1890, Gristhorpia (=Caytonia) Thomas, 1925, Baiera Braun in Münster, 1843, Otozamites Braun in Münster, 1843, Voltzia Brongniart, 1828, Yuccites (=Pelourdea) Schimper et Mougeot, 1844, Albertia Schimper, 1837 and Araucarites Presl in Sternberg, 1838. On the other hand, genera such as Hausmannia, Weltrichia and Elatocladus are here reported for the first time from Sardinia and also the dubitative record of Ptilozamites would represent the first occurrence in the Jurassic of Sardinia. In the future it will be necessary to complete the taxonomic analyses in order to identify the remains also at species level. Only then, it will be possible to compare the flora of Sardinia with the famous flora of Yorkshire. For a comparison with the historical flora of Rotzo a revision of the groups not studied in detail by Wesley (1966) will be necessary in order to gain a modern picture of the flora of southern Europe during the Jurassic. Additionally, it will be useful to compare the macroflora with palynological data from the Jurassic of Sardinia since the latter show a noticeable variety of fern spores (Gleicheniaceae, Schizaeaceae, Osmundaceae, Cyatheaceae, Dipteridaceae, Matoniaceae) and conifer pollen (Araucariacites, Classopollis, Spheripollenites, Pinuspollenites) (Del Rio, 1976; Dieni et al., 1983; Ashraf et al., 1984; Del Rio, 1984). ACKNOWLEDGEMENTS The manuscript has greatly benefited from constructive and explicative comments by Myriam del Rio (Univ. Cagliari), Johanna H.A. Van Konijnenburg-van Cittert (Univ. Leiden and Utrecht) and Mihai Popa (Bucharest). Financial support was provided by PRIN 2007 grant to A. Funedda.

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Manuscript received 19 April 2012 Revised manuscript accepted 5 July 2012 Published online 28 September 2012 Editor Edoardo Martinetto