PalynologicalPalynologicalSociety Society of Japan IPC-XIII / IOPC-IX Abstracts43 surviving in each time interva! was calculated. The results those published in 1997. The salinity variations, ranging show low and constant diversity values and high extinction from 29 to 34 psu in summer with minimum values during rates during the late Cretaceous and Paleocene. Near the the last glacial maximum, are almost identical. However, Paleocene-Eocene boundary a dramatic change in diversity the arnplitude of temperature changes is much Iarger, with occurs and the extinction rate abruptly decreases remaining warmer conditions than those previously reconstructed low until the Miocene, The results suggest that rapid during Belling-Allered (up to 160C instead ef70C) and the diversification episodes like the Paleocene-Eocene Thermal early Holocene (up to 150C instead of 10eC). The new Maximum are characterized by dramatic changes in the database thus permits reconstructions that evidence extinction rate. Ihe factors controlling these changes are particularly high sea-surface temperatures at time of still in debate. maximum summer insolation at high northem latitudes and extremely high sensitivity of the subpolar North Pacific with respect to elimate changes from glacial to interglacial. 092Reassessment of sea-surface conditions in the Glllf of Alaska during the ]ate P}eistocene-Holocene based on 093Diyersity dinocystassemb]ages of Late Devonian plants in Australia: contribution of the permineralized assemblage of Anne de Vernali, Sephie Bonneti, Taoufik Radi], Fabienne Barraba, NSW Marree Anne-Laure Decombeix, Brigitte Meyer-Berthaud, i GEOTOP, Uitiver:site du eutibec d Mbntrtiai, Mbntreat, MathildeEvreinoff Canado,[email protected] 2 Slthool ofEnvironmental Sleiences, Uhivensity ofLiverpool,b)iiv Mbnipellier2, UMI? AM;4P, Mbnipellie4 FL34000 ur 1 }'ance; (]NRS Uua AfiMP, MbnipeUie4 F-34000 Flunce, anne-taure.decombeix@eirady7' Reconstructions of the variations of sea-surface conditions in the Gulf of Alaska during the late Pleistocene and Most Late Devonian plant assemblages from Australia Holocene have been proposed more than ten years ago on described to date are preserved as the basis en dinocyst data (de Vemal and Pedersen, compressionslimpressions. They document a low diversity Paleoceanogmpiry 1997; Marret et al,, dan. J. Earth flora dominated by the arborescent lycepsid Leptophtoeum. sciences 2001). These reconstructions were made by using A notable exception is the small assemblage of a database that included no more than 371 sites located in permincralized plants from the late Famennian locality of North Atlantic and Arctic-subarctic. Since then, the Barraba, in New South Wales. These specimens decument "modern" standardized dinocyst database has been the presence of taxa net represented in the significantly enlarged with data from the Nonh Pacific and compressionlimpression assemblages and show that the werc more than the Bering Sea (cf Radi and de Vernal, Mdrine LateDevonian florasof Australia diverse M}'cropateontology 2008; Bonnet et al., Mdrine traditionally thought. After the initial description of the vacropaleontology 2012; Geotop website), which makes it ctadoxylopsid Polywylon by Chambers and Regan (1986), the BarTaba locality was initiated during more suitable for paleoceanographic reconstructions in the furtherwork on North Pacific. The Nenhern Hemisphere dinocyst database recent years based on museum specimens (Museum now includes close to 15eO sites with about 3SO sites from Victoria, Melbourne) and new rnaterial collected in 2004. the Pacific, Hence, it seems relevant to revisit the Additional evidence of the presenee of the cladoxylopsids and paleoceanography of the Gulf of Alaska based on the last in Australia is previded by a Hierogramma-like axis, 23000 years dinocyst record from core PAR-87AIO possibly by a small axis that represents a new taxon, The (-44022'N, 148e28"W). The dinocyst assemblages are presence of the cosmopolitan progymnosperrn genus characterized by concentrations of the order of 103 cysts Archaeopteris, which was only represented in Australia by cm'3 and the eceurrence of Ciperculodinium centrocarpum, rare compressions/impressions ef foliage resembling A. the occurrence of wood Nematosphaeropsis labyrinthus, spinijbrites elongatus s.1., halliana,issupported by Catlirylon of the rachis Ryxidinopsis reticulata, lhipagidinium patlidum, 7>'tfilievitype.A Kblymma (Calamopityales) Penttrpharsodinium dolei, and Brigantedinium spp. The represents the oldest evidence of seed plants in Australia, from Barraba samples from the last glacial interval, which contain Altogether, the ferns s.1, and lignophytes with dominant I. pallidum and Brigantedinium spp., have reveal important similarities at the generic level modern analogues in the Arctic and subarctic seas adjacent contemporaneous floras from Laurussia but also some to the North Atlantic. The samples from the postglacial degree ofendemicity, Our most recent work has focused on interval are characterized by dominant (lperculodinium the lycepsids, which are represented in the assemblage by 2 centrocarpum, iVlematosphaeropsis iab.yrinthus, and specimens: (1) a bisporangiate cone about 5 cm wide and in spinij2rrites elongatus s.t.; they have good modern 7.5 cm long, and (2) a small leafy axis 8 mm diameter. analegues in thc northeast Nonh Pacific. The The cene, a unique museum specimen, was imaged using reconstructions of sea-surfaee conditiens based on the High Resolution X-ray Computed Temography at the updated clatabase shew similar trends and fiuctuations than European Synchrotron Radiation Facility in Grenoble, NII-Electronic Library Service PalynologicalPalynologicalSociety Society of Japan 44Japanese Journal ofPalynology 58 (Special Issue) (2012) France. This allowed for a non-destructive study of the mainly belonging to fems. Many typical Jurassic elements, specimen and provided an extremely detailed 3D such as thniapteris gaojiatianensis, Selaginellites reconstruction ofits morphology and anatomy. In addition, drepanqformis, Equisetites lateralis, Raphaelia diamensis, micro- and megaspores were isolated frem the specimen Ginkgoites sibiricus, SPhenobaiera longijblia and and observed using SEM. All the gathered data suggests thekanowskia rigida demonstrates that the age of this that the cone represents a new merphetaxon. The small assemblage is midclle Early Jurassic. 5. leafy axis, studied with serial peels and thin-sections, shows Phlebopteris-Mbrattiopsis Assemblage, from the sigriificant differences frem Leptophloeum axes that occur Sangonghe Formation, consists of 23 species in 15 genera, as compressionsfimpressions at the locality. Its anatomy is which is markedly characterized by many therrnophilic very similar to that of the cone axis and it is likely that elements and several species of Cbniqpteris. The these two specimens correspond to the vegetative and thermophilic elements include Phlebopteris poLnpodioides fertile parts ofa same plant. They demonstrate the presenee of Matoniaceae, Dictyophyllum of Diptoptaceae, in the Late Devonian of Australia of a new lycopsid taxon Mdrattiopsis asiatica of Marattiaceae, Zbmites of that was probably growing in a different environment than Cycadales, scale-like leaf conifer Braciuiplryllum Leptophloeum, (Mnneriella?) and a pessible gnetalean plant cadtnisega ephedroides. This assemblage is late Early Jurassic in age and possibly Iinks with the Toarcian global paleoenvironment event in ecean. 6. Coniopteris-Phoenicopsis Assemblage contains in the 094Eyollltion Xishanyao Formation, representing the evolution peak of of the fioras throllgh the Late Triassic to the the Jurassic floras in Xiniiang. It censists of more than 60 Middle Jllrftssie based on the materials from one section species, which include the Bryophyta, Lycophyta, in the Junggar Basin, NW China Sphenophyllales, Filicopsida, Cycadopsida, Ginkgoposida, Coniferepsida and some classification unknewn cones and StbgngbgLPgugh hD ,YuanzhengLu seeds and is obviously dominated by the Filicopsida and Ginkgeposida. It is comparable with the Middle Jurassic Research institute ofPetroteum Exploration and Yorkshire Flora and other Middle Jurassic floras in China, Development, China, [email protected] and therefore is considered as the Middle Jurassic in age. The Haojiagou Section of the Junggar Basin, Xirijiang Kewerds: flora, assemblage, evolution, Late Triassic, Province, Northwestem China, has been a continually Jurassic. developed of the Upper Triassic to the Lower Cretaceeus. [[he lithostratigraphical successien of the Upper Triassic and the Lower and Middle Jurassic, which yield abundant plant fossirs are the HaQjiagou Fm.(Tjh), Badaowan Fm. (Jib), Sangonghe Fm. (Jis) and Xishanyao Fm. (J2x) in 095Mi]lennial of rnore ascending order. Based on the studies than a scale yegetation and c]imatic variability decade, five floral assemblages were established te show during past interglacial stages in NW Iberia - A focus the evolution ef the flora through the Late Triassic to the onMIS9and11 Middle Jurassic in the Junggar Basin of Northwestern China. 1. Danaeopsis-Cladophlebis ichunensis Assemblage, St!Cphgpig-Pgsp!a!th D ti,MariaFernandaSanchezGenii,Bruno contained in the Lower Member of the HaQjiagou Malaize2, Linda Rossigno12 Formatien, consisting of 19 species in 13 genera, is t dominated by ferns that belong te the Maratiaceae, EPHE (lhivensita Botdeaux i - EPOC, France, Osmundaceae, Dipteridaceae, CJadophtebis and s,[email protected]