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A new fossil conifer wood —Brachyoxylon currumilii sp. nov.— is described from the Lower—Middle Jurassic of Chubut Province (Argentina). The specimens were collected at a locality where the Cañadón Asfalto Formation is exposed, in the vicinity of the Cerro Cóndor village. The studied wood is characterized by mixed pitting in radial tracheid walls (predominantly uniseriate), araucarioid cross fields, low uniseriate rays and the absence of resin canals. The use of transmitted light and epifluorescence microscopy together with SEM imaging allowed the identification of additional characters such as the presence of pitting with torus-margo and compression wood. These characters are discussed in terms of their systematic relevance. On these grounds, the systematic affinity of the studied wood is discussed and linked to the extinct conifer family Cheirolepidiaceae, one of the dominant plant groups during the Jurassic and Cretaceous in Patagonia. Se describe una nueva especie de madera fósil de conífera, Brachyoxylon currumilii sp. nov., del Jurásico Inferior a Medio de la provincia de Chubut, Argentina. Los especímenes estudiados fueron coleccionados en una localidad donde aflora la Formación Cañadón Asfalto, en las cercanías de la aldea de Cerro Cóndor. Los troncos, estudiados, se caracterizan por el punteado radial de las traqueidas de tipo mixto, predominantemente uniseriado, campos de cruzamiento de tipo araucarioide, radios uniseriados bajos y ausencia de canales resiníferos. La observación bajo MEB y microscopio con luz transmitida y epifluorescencia permitió además la identificación de caracteres tales como la presencia de torus-margo en las punteaduras y estructuras de leño de compresión. Ambos caracteres son discutidos en relación a su relevancia sistemática. Sobre esta base, se discute la afinidad sistemática de la madera estudiada, la cual posee rasgos que la vincularían con la familia de coníferas extintas Cheirolepidiaceae, uno de los grupos de plantas dominantes durante el Jurásico y Cretácico de Patagonia. Fil: Bodnar, Josefina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Área Paleobotánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cúneo, Néstor Rubén. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gnaedinger, Silvia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentina

Several conifer species assigned to the Cheirolepidiaceae and one species assigned to the Taxodiaceae are described from the Early Cretaceous Puddledock locality, Virginia, eastern USA. The cuticular and gross morphology of the vegetative shoots indicates the presence of the genera Pseudofrenelopsis Nathorst, Frenelopsis Schenk and Athrotaxis D. Don. Most of these genera have been described from other Early Cretaceous localities in North America, South America, Europe, Africa and Asia. However, a study of the material from Puddledock has revealed some new morphological characters which allow an emended diagnosis of Pseudofrenelopsis . A new species of Pseudofrenelopsis is then described based on specimens combining characters of Pseudofrenelopsis and Frenelopsis . A new genus Watsoniocladus with Cupressinocladus valdensis (Seward) Seward as type species, has been established for cheirolepidiaceous shoots with opposite decussate or whorled phyllotaxis. Two new species and one undetermined species, have been assigned to the new genus. Taxodiaceous shoots referable to Athrotaxis ungeri (Halle) Florin, and a conifer shoot of unknown affinity are also described.

Nearly all data regarding land-plant turnover across the Cretaceous/Paleogene boundary come from western North America, relatively close to the Chicxulub, Mexico impact site. Here, we present a palynological analysis of a section in Patagonia that shows a marked fall in diversity and abundance of nearly all plant groups across the K/Pg interval. Minimum diversity occurs during the earliest Danian, but only a few palynomorphs show true extinctions. The low extinction rate is similar to previous observations from New Zealand. The differing responses between the Southern and Northern hemispheres could be related to the attenuation of damage with increased distance from the impact site, to hemispheric differences in extinction severity, or to both effects. Legacy effects of the terminal Cretaceous event also provide a plausible, partial explanation for the fact that Paleocene and Eocene macrofloras from Patagonia are among the most diverse known globally. Also of great interest, earliest Danian assemblages are dominated by the gymnosperm palynomorphs Classopollis of the extinct Mesozoic conifer family Cheirolepidiaceae. The expansion of Classopollis after the boundary in Patagonia is another example of typically Mesozoic plant lineages surviving into the Cenozoic in southern Gondwanan areas, and this greatly supports previous hypotheses of high latitude southern regions as biodiversity refugia during the end-Cretaceous global crisis.

 Premise of the study: Seed cone morphology and anatomy refl ect some of the most important changes in the phylogeny and evolutionary biology of conifers. Reexamination of the enigmatic Jurassic seed cone Pararaucaria patagonica reveals previously unknown systematically informative characters that demonstrate affi nities with the Cheirolepidiaceae. This paper documents, for the fi rst time, internal anatomy for seed cones of this important extinct Mesozoic conifer family, which may represent the ghost lineage leading to modern Pinaceae.  Methods: Morphology and anatomy of cones from the Jurassic La Matilde Formation in Patagonia are described from a combination of polished wafers and thin section preparations. New photographic techniques are employed to reveal histological details of thin sections in which organic cell wall remains are not preserved. Specifi c terminology for conifer seed cones is proposed to help clarify hypotheses of homology for the various structures of the cones.  Key results: Specimens are demonstrated to have trilobed ovuliferous scale tips along with a seed enclosing pocket of ovuliferous scale tissue. Originally thought to represent a seed wing in P . patagonica , this pocket-forming tissue is comparable to the fl ap of tissue covering seeds of compressed cheirolepidiaceous cones and is probably the most diagnostic character for seed cones of the family.  Conclusions: Pararaucaria patagonica is assigned to Cheirolepidiaceae, documenting anatomical features for seed cones of the family and providing evidence for the antiquity of pinoid conifers leading to the origin of Pinaceae. A list of key morphological and anatomical characters for seed cones of Cheirolepidiaceae is developed to facilitate assignment of a much broader range of fossil remains to the family. This confi rms the presence of Cheirolepidiaceae in the Jurassic of the Southern Hemisphere, which was previously suspected from palynological records.

Macroscopical and microscopical observations on extant and fossil plants have been made. Observations on extant plants led to study the effects of volcanic gases on the cuticle ultrastructure of Pinus halepensis and Erica arborea sampled in the volcanic area of Phlegrean Italy. TEM observations on P. halepensis cuticles fumigated or not by volcanic gases revealed: 1) insignificant thickness variations of the cell wall plus cuticle among current- and first-year-old needles of both fumigated and not fumigated trees; 2) a calcium oxalate accumulation in fumigated leaves; 3) moreover, in respect to the cell surface, fibrils are disposed parallel to the surface of the cuticle. In specimens of E. arborea fumigated or not by volcanic gases, 1) the total thickness of cuticles varies significantly; 2) in plants experiencing chronic fumigation the A2 layer increases its thickness. As for fossil plants, the cuticles of Cretaceous Fossil-Lagertätten of Cusano Mutri and Pietraroja have been studied. In the former: 1) numerous taxa belonging to conifers have been identified; 2) the new species Frenelopsis cusanensis has been described; 3) Montsechia vidalii has been found outside of Spain. Taxonomical studies allowed the description of typical Euro-Sinian fossil plants. Sedimentological and taxonomical studies suggest semi-arid or arid conditions in a subtropical or tropical climate. It is worth noting as for Cusano Mutri locality, evidence of wildfire (fusain) suggests a periodic combination of arid periods, high temperatures and lightning strikes., Des observations macroscopiques et microscopiques sur les plantes actuelles et fossiles ont été effectuées. Sur les plantes actuelles ont été effectué des observations relativement aux effets des gaz volcaniques sur l’ultrastructure des cuticules de Pinus halepensis et de Erica arborea récoltés dans l’aire volcanique des Campi Flegrei, Italie. Les observations conduites au TEM sur les cuticules de P. halepensis, influencé et non influencé par les gaz volcaniques, ont montré que : 1) l'épaisseur totale de la CM (cuticule) + CW (paroi pectocellulosique) ne subit pas de variations significatives d'épaisseur ; 2) la cuticule des aiguilles influencée par les gaz volcaniques montre une accumulation d’oxalate de calcium ainsi que 3) un réarrangement des fibrilles disposées parallèlement à la surface. Les observations conduites sur E. arborea ont permis de 1) constater que les épaisseurs totales des cuticules, influencées ou non par les gaz, sont significativement différentes ; 2) en présence de gaz volcaniques la couche externe A2 subit un accroissement d’épaisseur significatif. Par rapport aux macro-restes végétaux fossiles, les localités du Crétacé de Cusano Mutri et Pietraroja ont été étudiées. Le première site fossilifère a permis 1) d’identifier plusieurs taxa appartenant aux conifères; 2) de décrire une nouvelle espèce de conifère: Frenelopsis cusanensis; 3) de trouver l’angiosperme ancestrale Montsechia vidalii. L’étude taxonomique a permis de décrire des entités typiques de la Province Euro-Sinienne. L’étude sédimentologique et systématique montre un climat plutôt tropical-subtropical, des abondants fusains montrant des incendies naturels.

Nearly all data regarding land-plant turnover across the Cretaceous/Paleogene boundary come from western North America, relatively close to the Chicxulub, Mexico impact site. Here, we present a palynological analysis of a section in Patagonia that shows a marked fall in diversity and abundance of nearly all plant groups across the K/Pg interval. Minimum diversity occurs during the earliest Danian, but only a few palynomorphs show true extinctions. The low extinction rate is similar to previous observations from New Zealand. The differing responses between the Southern and Northern hemispheres could be related to the attenuation of damage with increased distance from the impact site, to hemispheric differences in extinction severity, or to both effects. Legacy effects of the terminal Cretaceous event also provide a plausible, partial explanation for the fact that Paleocene and Eocene macrofloras from Patagonia are among the most diverse known globally. Also of great interest, earliest Danian assemblages are dominated by the gymnosperm palynomorphs Classopollis of the extinct Mesozoic conifer family Cheirolepidiaceae. The expansion of Classopollis after the boundary in Patagonia is another example of typically Mesozoic plant lineages surviving into the Cenozoic in southern Gondwanan areas, and this greatly supports previous hypotheses of high latitude southern regions as biodiversity refugia during the end-Cretaceous global crisis. © 2012 Barreda et al. Fil:Barreda, V.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Cúneo, N.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Scasso, R.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Corollina sp. (Fig. 13M) OCCURRENCE. — Ashikajima and Kimigahama Fm. DESCRIPTION Pollen grain.Amb subspherical with poles flattened.At the proximal pole, a trilete mark is seen. At the distal pole, a pseudopore 3-7 µm in diameter is present.The rimula delimits a cap about 17-24 µm in diameter.No equatorial ridge is seen.The exine is psilate to slightly punctate. Equatorial diameter = 22-30 µm. REMARKS The genus Corollina gathers species from the Keuper without ridge, but it still remains used for the Cretaceous of southeastern Asia. BOTANICAL AFFINITIES Pinales, Cheirolepidiaceae (Couper 1958). Tekleva & Krassilov (2009) suggested an affinity with the Gnetales., Published as part of Legrand, Julien, Pons, Denise, Nishida, Harufumi & Yamada, Toshihiro, 2011, Barremian palynofloras from the Ashikajima and Kimigahama formations (Choshi Group, Outer Zone of south-west Japan), pp. 87-135 in Geodiversitas 33 (1) on page 115, DOI: 10.5252/g2011n1a6, http://zenodo.org/record/4597011, {"references":["COUPER R. A. 1958. - British Mesozoic microspores and pollen grains, a systematic and stratigraphic study. Palaeontographica 103 B: 75 - 179.","TEKLEVA M. V. & KRASSILOV V. A. 2009. - Comparative pollen morphology and ultrastructure of modern and fossil Gnetophytes. Review of Palaeobotany and Palynology 156: 131 - 139."]}

International audience; The Choshi Group, which crops out in the Outer Zone of south-west Japan, has been extensively studied for its rich macroflora by Makoto and Harufumi Nishida, among others, and was attributed to the Ryoseki-type Floristic Province by Kimura 0987). New microfloras were discovered in muddy, very fine-grained sandstones and mudstones of the marine Ashikajima and Kimigahama formations, representing the base of the Choshi Group. The authors provide a palynological inventory for these lithological units, which have been dated as Barremian on the basis of the ammonites recorded from them, and compare them with the paleofloristic associations of the South-Laurasian Province (Brenner 1976) and Euro-Sinian Region (Vakhrameev 1991). The studied assemblages yielded 53 genera and 89 species of spores and gymnosperm pollen grains, and also marine or freshwater al-gae and some epiphyllous fungi. No angiosperm pollen grain was observed. Four new species are described: Manumia japonica n. sp., Foveosporites gosekiensis n. sp., Nodosisporites choshiensis n. sp. and N makotoi n. sp. Other forms, probably new species, are described here in detail, but the scarcity of the specimens has led us to place them temporarily in open nomenclature. The spatio-temporal distributions of the genus Manumia Pocock, reported for the first time in Asia, and Cicatricosisporites sinuosus Hunt, 1985 are plotted on paleogeographical maps. With this palynological study, we add new data to the present knowledge of Barremian floras. This assemblage probably corresponds to a taphocenose. The authors suggest that the climate indicated had marked dry and more humid seasons, in accordance with the hypothesis of a moderate migration of the oceanic islands of the Outer Zone before their collision with the Eurasian continent, or moderate climatic change during the Early Cretaceous in Japan.

International audience; El Soplao outcrop, an Early Cretaceous amber deposit recently discovered in northern Spain (Cantabria), has been shown to be the largest site of amber with arthropod inclusions that has been found in Spain so far. Relevant data provided herein for biogeochemistry of the amber, palynology, taphonomy and arthropod bioinclusions complement those previously published. This set of data suggests at least two botanical sources for the amber of El Soplao deposit. The nrst (type A amber) strongly supports a source related to Cheirolepidiaceae, and the second (type B amber) shows non-specific conifer biomarkers. Comparison of molecular composition of type A amber with Frenelopsis leaves (Cheirolepidiaceae) strongly suggests a biochemical affinity and a common botanical origin. A preliminary palynologlcal study indicates a regional high taxonomical diversity, mainly of pteridophyte spores and gymnosperm pollen grains. According to the preliminary palynologlcal data, the region was inhabited by conifer forests adapted to a dry season under a subtropical climate. The abundant charcoalified wood associated with the amber in the same beds is evidence of paleofires that most likely promoted both the resin production and an intensive erosion of the litter, and subsequent great accumulation of amber plus plant cuticles. In addition, for the first time in the fossil record, charcoalified plant fibers as bioinclusions in amber are reported. Other relevant taphonomic data are the exceptional presence of serpulids and bryozoans on the surfaces of some amber pieces indicating both a long exposure on marine or brackish-water and a mixed assemblage of amber. Lastly, new findings of insect bioinclusions, some of them uncommon in the fossil record or showing remarkable adaptations, are reported. In conclusion, a documented scenario for the origin of the El Soplao amber outcrop is provided.

International audience; Pitt Island, a part of the Chathams Islands group, lies 700km east of New Zealand. Its geology includes the Tupuangi Formation, dated as Motuan to Teratan (late Albian to Santonian) on the basis of palynology. Samples of Tupuangi Formation mudstone yielded leaf cuticle assemblages dominated by araucarian and podocarp conifers and locally by angiosperms. The 12 distinguishable conifer taxa include a new species of Araucaria, A. rangiauriaensis, and the extinct genera Eromangia, Kakahuia (both Podocarpaceae), Otwayia (Cheirolepidiaceae), Paahake (Taxodiaceae or Taxaceae) and possibly Katikia (Podocarpaceae). Ginkgo and two types of dicotyledonous angiosperm cuticle are present. Based on the absence of bennettitaleans and rarity of Ginkgo, a Turonian or slightly younger age is inferred, making the Pitt Island assemblage the first Turonian plant macrofossils documented from New Zealand. The fossils provide a window into southern high-latitude (polar) vegetation of the mid-Cretaceous. Conifer charcoal (probably of Podocarpaceae) is locally abundant and suggests that fire was an important part of the ecosystem. A broad analogy with modern boreal conifer-deciduous angiosperm forests is suggested although clearly with warmer temperatures.

Resume Les marnes grises de l'Albien superieur de la region de Sainte-Anne-d'Evenos (Var, France) ont livre plusieurs fragments de bois fossiles flottes associes a des sediments marins ou abondent des organismes pelagiques. Deux structures homoxylees de Coniferales Cheirolepidiaceae ont ete identifiees: Brachyoxylon brachyphylloides (Torrey) Krausel et Brachyoxylon sp., Les bois etudies sont identiques a plusieurs specimens d'âge cretace inferieur decouverts a l'Est des U.S.A. et a l'emplacement du futur bras de mer Tethys-Benoue. Des conditions climatiques et ecologiques ont ete deduites de l'observation de certains caracteres (cernes d'accroissement) et de l'etude sedimentologique des sediments encaissants. Une reconstitution paleogeographique de la Basse-Provence a l'Albien superieur est proposee.

The paleoenvironmental and paleoclimatic significance of Cretaceous flora in the Neuquén Basin is summarized. Berriasian-Barremian terrestrial palynological assemblages are dominated by Araucariaceae and Cheirolepidiaceae, with subordinated podopcarps, ferns, lycopsids and bryophytes that progressed in a mild and humid climate. Tithonian-Barremian dinoflagellates mostly possess Mediterranean affinities. Upper Barremian evaporitic strata represent the final cycle of marine deposition related to the Pacific ocean in the basin. In the Aptian appear the first angiosperm pollen grains. Aptian-Cenomanian terrestrial palynological assemblages are characterized by the presence of northern Gondwana forms such as Afropollis and elaterate pollen grains. Tempskyaceae and Ginkgoales are also present in the late Early Cretaceous. Turonian-lower Campanian continental strata mostly include petrified wood and charophytes. Upper Campanian-Maastrichtian strata yield a rich terrestrial palynological assemblage composed by Nothofagaceae, Podocarpaceae, Cheirolepidiaceae, Araucariaceae, Salviniales and angiosperms, but also dinoflagellates that reflect the beginning of a marine transgression related to the Atlantic ocean. The presence of locally abundant cycads and palms suggests a warm and relatively humid climate towards the end of the Cretaceous. Fil:Ottone, E.G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Based on rich material from localities in W. Germany of Early Liassic age, coniferous remains assignable to Hirmeriella muensteri (family Cheirolepidiaceae) have been thoroughly studied with the aid of cuticle analysis. Detailed information of the ovuliferous dwarf-shoots, with emphasis on the nature of the inner cuticles combined with reinterpretation of the number of pollen sacs in the pollen cones, necessitates an emendation of the species diagnosis. Emendations at the generic and family level are also proposed. Based on the new data presented here, the ovule-covering structures in the Cheiropidiacae are interpreted as epimatia; these can be characterized by free margins (Hirmeriella) or margins fused with the dwarf-shoot (Frenelopsis). The lack of a pollen chamber combined with a new interpretation of the peculiar organization of Classopollis, indicates a rather modern pollination system.

A multidisciplinary analysis of palynofacies in a sequence-stratigraphical framework, TOC (total organic carbon) and TAI (thermal alteration index) analyses, has been applied to outcrop samples of the uppermost Los Molles Formation (Middle Jurassic), Neuquen Basin, Argentina, in order to characterise the palaeoenvironmental and palaeo-climatic conditions during the deposition of this unit. Five types of palynofacies (P-l to P-5) have been identified and are interpreted to indicate a restricted marine to inner neritic environment. In P-1 and P-4, a marine environment close to the terrestrial source area with moderate oxidizing conditions and energy, is suggested. In P-2, the assemblage of freshwater algae, acritarchs and prasinophytes suggest a marginal marine environment influenced by fluvial discharge. In P-3, the marine microplankton content reflects conditions ranging from a marginal-marine (sub-normal salinity) to an inner neritic environment. In P-5, a dysoxic marine environment (probably marginal) is suggested. Warm and relatively humid (abundance of Cheirolepidiaceae in association withAraucariaceae) and locally humid (presence of swamps or ponds, on the alluvial plains) conditions are inferred. TOC content (65% of the analyzed samples reach TOC values over 1%), TAI values (2 to 2+, transitional between an immature phase and the window of liquid petroleum generation) and kerogen type (P-1, P-2 and P-5 show transitional characteristics between kerogen type II and III, while P-3 and P-4 show characteristics of kerogen type III and occasionally type IV), suggest that, in the studied area, the Los Molles Formation has some hydrocarbon potential. However, kerogen state suggests that the anoxic-dysoxic conditions of the site of deposition were not optimum for its preservation.

Terpenoid resin is produced by all families and most genera of the order Coniferales (the conifers), and the distribution of terpenes present in most conifer resins is characteristic of the originating family. Analyses of early Cretaceous (Barremian) amber (fossil resin) from the English Wealden, Isle of Wight, southern England, by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), indicate a terpene distribution dominated by abietane- and labdane-type terpenes. Similar distributions are observed in some species of the extant family Pinaceae. The Pinaceae are well represented within the Wealden deposits of southern England, by only one (known) species, Pityites solmsii (Seward) Seward, whereas the macro-fossil record of these deposits is dominated by the extinct conifer family Cheirolepidiaceae, for which no resin chemistry has been reported. By analogy with modern materials, it is probable that the ambers found in these deposits are derived from an extinct member of the Pinaceae, but given the absence of evidence concerning the chemotaxonomy of the Cheirolepidiaceae, this family cannot be excluded a priori as a possible paleobotanical source. These ambers may therefore be assigned to either the Pinaceae or to the Cheirolepidiaceae. These samples are the oldest ambers to date to yield useful chemotaxonomic data.

An unusual combination of pollen characters imparts a unique identity to the Mesozoic Circumpolles: the absence of sacci, the tetrad or dyad configuration, heteropolarity marked by the aperturoid thinnings, a distal pore fortified by an endo-annulus, the occurrence of exinal filaments and spherules, the development-transition-diminution of supratectal sculpture, tectal complexity, grades of columellar complexity, the presence of lamellate nexine and the development, multiplication and disappearance of endoridges. Analogous or homologous pollen characteristics in other taxa belonging to various plant groups, as well as the functional significance of important features and their conjectured evolutionary trends and adaptive values are discussed. Characters such as tetrad or dyad configuration, exinal filaments and tectal complexity partly comparable with those in extant angiosperms, are not encountered in living gymnosperms.

Well over 150 spore and pollen taxa have been recorded in the literature from the Crato Formation and other slightly older and younger formations in the Chapada do Araripe, but detailed information on stratigraphic occurrences and relative abundances is mostly lacking. As a result, it is difficult to draw precise biostratigraphic and palaeoenvironmental conclusions, and impossible to recognize any changes in climate and depositional conditions upwards through the succession on the basis of the published record of these plant microfossils. By a process of elimination it is reasonable to suggest an age range of late Aptian to early Albian for the formation from the data presented. It may also be inferred that during the time it accumulated much of the surrounding vegetation was adapted to semi-arid conditions, although there must also have been some habitats that were able to sustain moisture-loving and aquatic plants. The latter is emphasized by the palynological composition of two samples examined specifically for consideration in this chapter, which are unequivocally from the Crato Formation. The assemblages recovered also suggest that the formation is more likely to be late Aptian than early Albian in age. In addition, evidence of reworking of Devonian deposits is apparent. A few of the spores and pollen grains recovered are illustrated (Figure 20.1 and Plate 32).

The Heiligkreuz-Santa Croce Formation (also known as Durrenstein Formation, Upper Triassic) in the Dolomites contains one of the most ancient and substantial Triassic amber deposits in the world. The amber is found in sandstones and paleosols. It has an affinity to the conifer family Cheirolepidiaceae, and amber samples from the Julian and Carnic Alps (Southern Alps) also show an affinity to this family. Physico-chemical investigations of the amber from the Dolomites by solid-state Fourier-transform infrared analysis (FTIR), nuclear magnetic resonance (NMR), pyrolysis-gaschromatography/mass-spectrometry (pyr-GCIMS), thermogravimetry (TG), differential thermogravimetry (DTG), and automatized elemental analysis yielded a complete characterization of the amber, and allowed comparison with other ambers and younger resins (copals). FTIR revealed absorption bands typical of all fossil resins, and the spectrum region from 8-10 mu m provided a fingerprint of the Triassic amber that differs front other known resins. The NMR spectrum also shows a typical pattern for fossil resins, but peculiar peak abundances permitted further characterization of the Triassic amber, both in the saturated (10-70 ppm) and unsaturated carbon region (100-160 ppm). The amber also lacks exomethylene resonances found in younger resins at 110 and 150 ppm. Pyrolysis-gas-chromatography/mass-spectrometry (pyr-GCIMS) experiments showed the amber was of class II, with some components of Class L Thermogravimetric (TG) and differential thermogravimetric (DTG) analyses of combustion behavior of Triassic amber indicated a main exothermal event near 437 degrees C, higher than that of other known resins. The elemental composition of Triassic amber is consistent with wellknown constituents of natural resins, although the sulfur content was higher, likely due to high sulfur content in the embedding sediment. Triassic amber from the Dolomites appears to be a new kind of fossil resin with unique stratigraphical and physico-chemical characteristics.

Stomatal characteristics of an extinct Cretaceous conifer, Pseudofrenelopsis parceramosa (Fontaine) Watson, are used to reconstruct atmospheric carbon dioxide (pCO2) over a time previously inferred to exhibit major fluctuations in this greenhouse gas. Samples are from nonmarine to marine strata of the Wealden and Lower Greensand Groups of England and the Potomac Group of the eastern United States, of Hauterivian to Albian age (136-100 Ma). Atmospheric pCO2 is estimated from the ratios between stomatal indices of fossil cuticles and those from four modern analogs (nearest living equivalent plants). Using this approach, and two calibration methods to explore ranges, results show relatively low and only slightly varying pCO2 over the Hauterivian-Albian interval: a low of ∼560-960 ppm in the early Barremian and a high of ∼620-1200 ppm in the Albian. Data from the Barremian Wealden Group yield pCO2 values indistinguishable from a soil-carbonate-based estimate from the same beds. The new pCO2 estimates are compatible with sedimentological and oxygen-isotope evidence for relatively cool mid-Cretaceous climates. © 2005 Geological Society of America.

We document a new species of ovulate cone (Pararaucaria collinsonae) on the basis of silicified fossils from the Late Jurassic Purbeck Limestone Group of southern England (Tithonian Stage: ca. 145 million years). Our description principally relies on the anatomy of the ovuliferous scales, revealed through X-ray synchrotron microtomography (SRXMT) performed at the Diamond Light Source (UK). This study represents the first application of SRXMT to macro-scale silicified plant fossils, and demonstrates the significant advantages of this approach, which can resolve cellular structure over lab-based X-ray computed microtomography (XMT). The method enabled us to characterize tissues and precisely demarcate their boundaries, elucidating organ shape, and thus allowing an accurate assessment of affinities. The cones are broadly spherical (ca. 1.3 cm diameter), and are structured around a central axis with helically arranged bract/scale complexes, each of which bares a single ovule. A three-lobed ovuliferous scale and ovules enclosed within pocket-forming tissue, demonstrate an affinity with Cheirolepidiaceae. Details of vascular sclerenchyma bundles, integument structure, and the number and attachment of the ovules indicate greatest similarity to P. patagonica and P. carrii. This fossil develops our understanding of the dominant tree element of the Purbeck Fossil Forest, providing the first evidence for ovulate cheirolepidiaceous cones in Europe. Alongside recent discoveries in North America, this significantly extends the known palaeogeographic range of Pararaucaria, supporting a mid-palaeolatitudinal distribution in both Gondwana and Laurasia during the Late Jurassic. Palaeoclimatic interpretations derived from contemporaneous floras, climate sensitive sediments, and general circulation climate models indicate that Pararaucaria was a constituent of low diversity floras in semi-arid Mediterranean-type environments.

Serial sections for light microscopy or transmission electron microscopy of two Classopollis pollen tetrads show that the exine structure, except for the nexine, has radially arranged rodlike units interwoven with transverse subunits. The nexine consists of strands or thin sheets except in the equatorial infratectal striate band area, where it is up to ca. 1 μm thick. Nexine is absent in the areas of the distal cryptopore and the subequatorial circumpolar infratectal canal. It is very thin or absent in the tetrad scar. Native contrast and reactivity to stain disappeared on immersion of thin sections in 1 M NaOH or HCl or in water. Reactivity to stains was regained after oxidizing the sections in KMnO4. Reactivity to stains appears to be dependent upon non-sporopollenin molecules embedded within exines. The above immersions remove stain reactive sites. Oxidative etching of sporopollenin exposes new sites. The specimens of Classopollis classoides Pflug studied and illustrated were picked from an Upper Jurassic sample (CRC 31519-2) collected at Osmington Mills locality, Dorset, England.

Remains of Pseudofrenelopsis parceramosa (Fontaine) Watson (Cheirolepidiaceae) from the Wealden of the Isle of Wight have been examined from the point of view of the branching and mode of growth of the plant. Evidence is presented that the tree exhibited seasonal growth and that the young extension shoots bore numerous temporary ultimate branch? is of limited growth. The tree was probably adapted to warm seasonally arid conditions.

Flat, frond-like conifer shoots from the Upper Cretaceous of the eastern United States have been described in the past as three species of the genus Androvettia Hollick & Jeffrey. The characteristics of Androvettia are discussed and compared with descriptions of Moriconia Dehey & Ettingshausen. Specimens of all three species, including new material, have been studied by light and scanning electron microscopy. It is concluded that only one species, Androvettia statenensis Hollick & Jeffrey, is represented. The morphology and phyllotaxis of the shoots, which are phylloclades, are illustrated and discussed. Two forms of branches are present which it is suggested represent shoots of determinate and indeterminate growth. Membership of the family Cheirolepidiaceae is tentatively suggested.

New material of Pagiophyllum maculosum Kendall from Cloughton Wyke is described, including large axes and branched leafy shoots and male cones. The male cones are described as Classostrobus cloughtonensis sp. nov. The male cones and pollen of the Cheirolepidiaceae are compared and summarized in a table.

Conifers of the Cheirolepidiaceae, on the basis of palynological evidence, extended from the Triassic to the Late Cretaceous or perhaps to the Early Tertiary. They were geographically widespread and especially important in the Jurassic and Early Cretaceous at low palaeolatitudes. Recent research on both pollen (Classopollis) and macroremains has demonstrated considerable diversity within the group. Aspects of pollen-exine structure, seed-cone organization as well as vegetative morphology and anatomy suggest high degrees of biological specialization. A number are believed to have been tropical halophytes but others probably occupied a wide range of warm habitats prior to the rise to dominance of angiosperms.

This paper reports the organic attachment of male and female cones to twigs previously described as Tomaxellia biforme Archangelsky. The male cones produce Classopollis pollen, while the scales of the female structures are comparable to the Rhaeto-Liassic northern genus Cheirolepidium. A new interpretation of the possible female cone of Cheirolepidium is presented, based on the new evidence now available with the knowledge of Tomaxellia cones. Other female cones found in Mesozoic formations may be comparable to some extent with Tomaxellia, such as Indostrobus (Cretaceous of India) or Pararaucaria (Jurassic of Argentina), and they may be grouped in the family Cheirolepidiaceae. Comparisons with older conifer genera with known female cones are also included (Voltziaceae). Some morphological changes of the female cones, which probably took place during the Mesozoic (in these particular groups) are also inferred.

A delta complex was important both as a source and a transport agency for plant material preserved in the early Cretaceous Wealden rocks of south-east England. The megafossils and larger microfossils are relatively restricted in their distribution in these rocks and are perhaps almost exclusively products of the delta flora. The pollen, small spores and microscopic plant fragments are widely dispersed and may represent the flora of both delta and hinterland. The composition and distribution of some of the delta plant communities are inferred from available data. The structure and development of the pre-angiosperm vegetation as a whole remains, however, largely the subject of speculation. Possible models are presented but whether they are feasible depends not only on the reliability of the plant fossil data but also on the acceptability of certain geological interpretations.