Well-preserved Pollen Research Articles

Formal ratification of the Global Boundary Stratotype Section and Point (GSSP) for the Chibanian Stage and Middle Pleistocene Subseries of the Quaternary System: the Chiba Section, Japan†

by Yusuke Suganuma, Makoto Okada, Martin J. Head, Koji Kameo, Yuki Haneda, Hiroki Hayashi, Toshiaki Irizuki, Takuya Itaki, Kentaro Izumi, Yoshimi Kubota, Hiroomi Nakazato, Naohisa Nishida, Masaaki Okuda, Yasufumi Satoguchi, Quentin Simon, and Yoshihiro Takeshita. Episodes 2021;44:317-47. https://doi.org/10.18814/epiiugs/2020/020080

Pollen assemblage and environmental DNA changes: A 4300-year-old bat guano deposit from Jamaica

The discovery of two undisturbed caves in Jamaica with 14C and 210Pb dating indicating that the oldest layers of guano were ca. 200 years old in the first cave (81 cm long core), and as much as 4300 years old in the second cave (129 cm long core) provides exciting possibilities to examine past ecological communities. We analyzed genetic and pollen profiles in these ancient bat guano deposits and revealed DNA sequences most similar to arthropods, mainly insects such as caddisflies (Trichoptera), butterflies (Lepidoptera) and mayflies (Ephemeroptera), suggesting a potential source for past dietary data. Palynological analysis failed to recover well-preserved pollen grains and spores older than ca. 200 years, however in layers preserving pollen, angiosperms were the most abundant plants observed, with a regular occurrence of the potato (Solanaceae) and pepper families (Piperaceae), which are frequently bat-dispersed. In general, changes in frequency of particular plant taxa appear to reflect changes of vegetation and land use in the cave vicinity; however, some changes could be linked to hurricanes, leading to forest canopy damage and promoting the growth of light-demanding species such as guarumo (Cecropia). Higher amounts of mangrove (Rhizophora) pollen have also been recorded in the periods of heavy hurricane activities. Our data highlight the value of bat guano deposits in caves as a resource for the analysis of past ecological systems and stress the conservation values of these deposits.

Modern pollen source and spatial distribution from surface lake sediments in the southwestern Pampa grasslands, Argentina: Implications to interpret Holocene pollen records

In the Pampa grasslands of Argentina nothing is known about the transport, deposition and spatial distribution of pollen in lakes. To analyze and understand how well lake surface sediment pollen assemblages reflect the contemporary vegetation in relation to pollen source area, bathymetry and grain size sediments 36 surface sediment samples from Chasicó Lake and 5 from its only tributary were analyzed. Lake pollen assemblages showed two major patterns above and below the range between 4 and 6 m depth. Below this range the percentage and concentration of main pollen taxa are relatively homogeneous, without overrepresented taxa and with well-preserved pollen. They reflect the extra-local and regional source areas from Pampa grasslands and xerophylous forest and indicate that pollen from cores taken below this range will be suitable for paleocological studies. Isopoll of the main taxa and grain size distribution maps allowed understand how pollen and sediment was transported, deposited and distributed in the lake. The spatial distributions of main pollen taxa differ considerably among them, generating various pollen assemblages at different sampling points. There is no significant correlation between total pollen concentration and both depth and grain size, suggesting that there are not a totally pollen and sediment focusing in the lake. The pollen distribution indicates that wind and surface runoff are the primary transport vectors to the lake. However, tributary also contributes with the waterborne pollen, particularly around the river mouth. Implications of these processes will be of particular interest for reliable interpretation of fossil pollen records in similar environments.

A summary of the Chiba Section, Japan

We propose the extensively studied Chiba section of the Chiba composite section (CbCS) as the Global Boundary Stratotype Section and Point (GSSP) to define the base of the Middle Pleistocene Subseries and Chibanian Stage. The CbCS is a continuous and expanded marine sedimentary succession within the middle of the Ko-kumoto Formation, Boso Peninsula, Chiba Prefecture. It contains well-preserved pollen, marine micro-and macrofossils, a tightly-defined Matuyama-Brunhes (M-B) paleomagnetic polarity boundary, and numerous tephra beds, allowing the establishment of a robust and precise chronostratigraphic framework across the Lower-Middle Pleistocene boundary. Its deep-marine, open-ocean continental slope setting, coupled with high sedimentation rates with no evidence of abrupt deposition, has resulted in preserving both terrestrial and marine environmental changes in and around Marine Isotope Stage (MIS). We have performed high-resolution oxygen isotope analysis , as well as detailed sedimentological, geochemical, and biostrati-graphic studies of the CbCS, confirming the completeness of the stratigraphic interval spanning the Lower-Middle Pleistocene boundary. The M-B polarity boundary serves as the agreed primary guide for the Lower-Middle Pleistocene boundary, and the CbCS represents one of the most detailed marine sedimentary records yet obtained for this reversal, yielding an astronomical age of. ka with a duration of ca.. kyr. This section therefore offers an exceptional opportunity to calibrate the geological time scale as well as understand the dynamics of the geodynamo. The widespread Byk-E tephra lies close to the reversal, allowing precise regional lithostrati-graphic correlation. The CbCS is easy to access from international airports. The section will be permanently preserved and maintained by the local government as a natural monument. Based on these attributes , the base of the Byk-E tephra bed in the Chiba section is the best horizon for establishing the GSSP that will define the Lower-Middle Pleistocene boundary.

Dietary and environmental implications of Early Cretaceous predatory dinosaur coprolites from Teruel, Spain

Coprolites from the Early Cretaceous vertebrate bone-bed at Ariño in Teruel, Spain, were analyzed geochemically and palynologically. They contain various inclusions, such as small bone fragments, abundant plant remains, pollen, and spores. We attribute the coprolites to carnivorous dinosaurs based partly on their morphology together with the presence of bone fragments, and a high content of calcium phosphate (hydroxylapatite) with calcite. Well-preserved pollen and spore assemblages were identified in all coprolite samples and a slightly poorer assemblage was obtained from the adjacent sediments, both indicating an Early Cretaceous (Albian) age. This shows that the coprolites are in situ and also confirms previous age determinations for the host strata. The depositional environment is interpreted as a continental wetland based on the palynoflora, which includes several hydrophilic taxa, together with sparse occurrences of fresh-water algae, such as Ovoidites, and the absence of marine palynomorphs.Although the coprolites of Ariño samples generally are dominated by pollen produced by Taxodiaceae (cypress) and Cheirolepidiaceae (a family of extinct conifers), the sediment samples have a slightly higher relative abundance of fern spores. The distribution of major organic components varies between the coprolite and sediment samples, which is manifest by the considerably higher charcoal percentage within the coprolites. The high quantities of charcoal might be explained by a ground-dwelling species, feeding on smaller vertebrates that complemented its diet with plant material from a paleoenvironment were wild fires were a part of the ecosystem. The state of preservation of the spores and pollen is also more detailed in the coprolites, suggesting that encasement in calcium phosphate may inhibit degradation of sporopollenin.

Cheirolepidiaceous diversity: An anatomically preserved pollen cone from the Lower Jurassic of southern Victoria Land, Antarctica

To date, the vast majority of fossils described for the extinct conifer family, the Cheirolepidiaceae, have been reported from compression/impressions primarily from Cretaceous rocks; there are fewer reports from permineralizations and the Jurassic. New specimens have recently been discovered in siliceous blocks composed of fusainized layers of plant remains that alternate with fine-grained sediments from the Carapace Nunatak (Lower Jurassic) locality of southern Victoria Land, Antarctica. Specimens were prepared using standard serial cellulose-acetate peel technique, transmitted-light microscopy, and SEM analysis. The cones are ellipsoidal, up to 5.5mm long, and consist of helically arranged microsporophylls, each with a slender stalk containing a single vascular bundle; the distal lamina is peltate and most closely resembles those of the Classostrobus. Four to seven pollen sacs are arranged in an annular cluster abaxial to the sporophyll stalk. In situ Classopollis pollen ranges from 18 to 60μm in equatorial diameter with an average diameter of 30μm. In addition to these well-preserved pollen cones there is a large diversity of vegetative conifer remains within the Carapace Nunatak material including leaf and stem fragments. The discovery of the pollen cones in combination with vegetative remains provides additional information on the reproductive biology of the Cheirolepidiaceae and increases the probability of developing a whole-plant concept for this Jurassic permineralized conifer.

The palynology of the Lower Permian (Asselian–?Artinskian) Copacabana Formation of Apillapampa, Cochabamba, Bolivia

The palynostratigraphy of the lower and Coal members of the Copacabana Formation from Apillapampa, central Bolivia was investigated. Twelve samples yielded abundant and diverse, moderately well-preserved pollen and spores. One new spore species, Dictyotriletes cousmineri, is described and 52 species are recorded for the first time in Bolivia. Two species each of acritarchs and scolecodonts are also present. The lowermost assemblage yielded Vittatina and taxa such as Pakhapites ovatus and Marsupipollenites striatus, which are characteristic of the Asselian–Early Artinskian Vittatina costabilis Zone of the Paraná Basin, Brazil. The uppermost assemblage is defined by the appearance of several species of Lueckisporites, together with species of Vittatina, Lunatisporites, Pakhapites, Hamiapollenites, Corisaccites, Mabuitasaccites, Striomonosaccites, Striatoabieites, Striatopodocarpites and Weylandites. Abundant monolete and trilete spores with subordinate pollen grains are present in the Coal Member. Those species suggest correlation to the Middle Artinskian–Wuachiapingian Lueckisporites virkkiae Zone of the Paraná Basin. Highly variable associations of gymnosperms occur in the lower member whereas pteridophytes, sphenophylls and lycopods are dominant in the overlying Coal Member. These groups of plants characterised terrestrial landscapes along marine margins during the Early Cisuralian, and confirm the widespread distribution of the Glossopteris flora during the Permian in Gondwanaland. Preliminary radiometric data from interbedded tuffs suggest an Asselian–Sakmarian age for the marine Copacabana Formation and a Sakmarian–?Artinskian age for the overlying Coal Member. These new data are highly significant in terms of Permian correlations in central South America.

The Lateglacial and early Holocene vegetation and environment in the Dovre mountains, central Norway, as signalled in two Lateglacial nunatak lakes

By using heavy coring equipment in two high-altitudinal lakes (1253 and 1316 m a.s.l.) at Dovre, Central Norway, 1–1.5 m of unsorted coarsely minerogenic sediments were retrieved below the Holocene organic sediments. The minerogenic sequence contained well-preserved pollen and chironomid remains, revealing new and detailed palaeoenvironmental knowledge of the mountains in Central Norway during the last 5–6000 years of the Lateglacial (LG) period. However, the LG chronology is based on biostratigraphical correlations and not on 14C-dates, due to low organic content in the minerogenic sediments. The emerging LG nunataks, probably indicating a thin and multi-domed Scandinavian ice-sheet, was rapidly inhabited by immigrating species which could explain the present centric distributions of certain arctic-alpine plants. The LG vegetation development included a pre-interstadial dominated by mineral-soil pioneers, an interstadial dominated by shrubs and dwarf-shrubs, and the Younger Dryas cold period with recurring dominance of pioneers. Pollen and stomata of Pinus and Picea indicate their local LG presence at Dovre. LG climate oscillations are indicated by pollen stratigraphy and for the later part of LG also by chironomids. These oscillations could correspond to Heinrich event 1, GI-1d, GI-1b, and the Younger Dryas cold events. The LG interstadial reached July mean temperatures of more than 7–8 °C, similar to the present. Chironomids colonized the lake already during the onset of the interstadial, albeit at very low richness and abundances. Starting from YD, there are sufficient chironomid head capsules to perform a temperature reconstruction. The Holocene warming of about 2 °C initiated a vegetation closure from snow beds and dwarf-shrub tundra to shrubs and forests. Birch-forests established about 10 ka cal BP, slightly earlier than pine forests. Alnus expanded ca 9.2 ka cal BP and a thinning of the local forests occurred from ca 7 ka cal BP. Two short-lasting climate deteriorations found in the pollen record and the chironomid record may represent the Preboreal Oscillation and the 8.2 event. The Holocene Thermal Maximum is indicated around ca 7.8–7.3 ka cal BP showing a chironomid-inferred July mean of at least 11 °C. This is ca 3 °C warmer than today.

Erdtmanitheca portucalensis, a new pollen organ from the Early Cretaceous (Aptian–Albian) of Portugal with Eucommiidites-type pollen

A new lignitised, slightly compressed pollen organ, Erdtmanitheca portucalensis, with affinities to extinct Erdtmanithecales from the Early Cretaceous (Aptian–Albian) of Vale de Água (Lusitanian Basin, western Portugal), is described. The pollen organ is composed of loosely arranged microsporophylls radiating from a central core. The estimated number of microsporophylls is about 100–150. The microsporophylls are sessile and ellipsoidal to barrel-shaped with a flattened or slightly apically depression containing about ten narrow sporangia. The sporangia enclose abundant well-preserved pollen grains of Eucommiidites-type. Pollen grains found in situ are elliptical in equatorial outline, about 16.0–27.2 μm long and 11.9–16.4 μm wide. The main (distal) colpus is long with expanded rounded ends. It is flanked by two subsidiary colpi in an almost equatorial position. The surface of the pollen wall is psilate and occasionally punctate. The ektexine is composed of a distinct tectum, granular infratectal layer and a thin foot layer. The endexine is thick and laminar. The new Early Cretaceous Portuguese pollen-organ is similar in several respects to that of Erdtmanitheca texensis described from the Late Cretaceous of Texas, USA. The new fossil species further documents the importance of the Bennettitales-Erdtmanithecales-Gnetales group in the Early Cretaceous floras of Portugal extending the stratigraphic and geographical distribution of the genus with regard to systematic and phylogenetic significance of the Eucommiidites-producing plants that may have been co-occurring with the Early Cretaceous diversification of angiosperms. It is ascertained that perforate tectum occurs in pollen grains with a well-developed foot layer as well as in pollen grains in which a foot layer is poorly developed or lacking, and that pollen features do not support a separation of the Erdtmanithecales seeds and pollen organs.

SPORES AND POLLEN FROM THE MIDDLE AND UPPER GHARIF MEMBERS (PERMIAN) OF OMAN

The late Early to Mid Permian palynomorph biozones OSPZ5 and OSPZ6 for the Arabian Peninsula sporadically contain diverse and well-preserved pollen and spore assemblages. These are described here for the first time, concentrating on taxa used in the recognition of biozones. Some of these forms were previously assigned to informal morphotypes. The new spore species Indotriradites ater, Indotriradites mundus, Kendosporites robustus, and the new pollen species Kingiacolpites subsaccatus and Tiwariasporis? granulatus are described and illustrated. These distinctive palynomorphs may be useful in future biostratigraphic studies. For example, the first uphole occurrences of Indotriradites mundus and Tiwariasporis? granulatus are close to the base of OSPZ6. Indotriradites ater and Kingiacolpites subsaccatus have relatively narrow ranges within OSPZ5. Hamiapollenites dettmannae and Hamiapollenites karrooensis are common in the lower part of OSPZ5.

The pollen cones of Ginkgo from the Early Cretaceous of China, and their bearing on the evolutionary significance

A well-preserved pollen cone of the genus Ginkgo was found in the Yixian Formation (Early Cretaceous) of Liaoning Province, China, and is described as the new species Ginkgo liaoningensis. The pollen cone, catkin-like, consists of a main axis bearing scales at its base and spirally arranged sporophylls bearing 3–4 (−2) oval or elliptical sporangia. The sporangia are pendulous and dehiscent by a longitudinal slit. The mature pollen grains are monocolpate and elongate-elliptical, and the juvenile pollen grains are found in the tetrad stage. The characteristics of G. liaoningensis are very similar to those of the living Ginkgo biloba, but the sporophylls of G. liaoningensis bear 3–4 (−2) sporangia, whereas those of G. biloba bear mostly two sporangia. G. liaoningensis differs from fossil cones of Ginkgo huttoni from the Jurassic of Yorkshire, UK, and an unnamed specimen of Ginkgo from the Upper Cretaceous of Alberta, Canada, in the size and number of sporangia. The comparison between G. liaoningensis (fossil) and G. biloba (living) supports the reduction hypothesis of ovule organs in Ginkgo, with the number of sporangia having experienced the process of reduction from three or four to two since the Early Cretaceous.

Vegetation reconstruction on the basis of pollen in Late Pleistocene hyena coprolites from San Teodoro Cave (Sicily, Italy)

Vegetation reconstruction based on pollen from coprolites of extinct spotted hyena ( Crocuta crocuta spelaea, Goldfuss 1832) recovered from excavations carried out in 1998 at San Teodoro Cave (Sicily, Italy) supports previous indications of pre-Late Glacial conditions. Eight of the twelve coprolites analysed contained well-preserved pollen grains. There is a general similarity between the pollen contents from the coprolites but they show variability. They suggest a main vegetation type dominated by steppic taxa (Poaceae, Artemisia, Ephedra, Chenopodiaceae and Asteraceae) but also including arboreal taxa ( Pinus and Cupressaceae). Low percentages of pollen of mesophilous woody taxa ( Quercus, Betula, Abies, Alnus, Pistacia, among others) are noticeable, suggesting the existence of nearby refugia for temperate and Mediterranean vegetation. A reconstruction of the landscape, using the coprolite pollen record and other pollen records from Sicily and south Italy, shows the predominance, during the pre-Late Glacial, of a wooded steppe biome, with elements representing a variety of local environmental conditions.

WARM CLIMATE IN THE LATE MIOCENE OF THE SOUTH COAST OF ALASKA AND THE OCCURRENCE OF PODOCARPACEAE POLLEN

Abstract A study of the Homerian type section in the upper Beluga Formation (Upper Miocene) of the Kenai Group of southern Alaska has yielded two surprising discoveries: (1) warmth-loving taxa and (2) the presence in Alaska of a ‘new’ gymnosperm family, Podocarpaceae. A well-preserved pollen and spore flora is present in Upper Miocene coal beds of the Kenai lowland, near Homer, Alaska. Stump horizons, abundant wood fragments, wood grain, and amber within the coal attest to a forested swamp. Pollen assemblages from the Homerian type section include elements of both Mixed Northern Hardwood and warm-temperate Mesophytic forests and are far richer than the flora previously defining the Homerian type section, which had suggested a less diverse, cooler assemblage. Within the Homerian type section, the flora exhibits no definite taxonomic chronology; in general, Alnus dominates, with up to 45% of the total counts, followed by Pinaceae and Taxodiaceae pollen types (30 to 35%) and thermophiles (c. 14%). At least 3...

Le gisement pliocène final de Saint-Vallier (Drôme, France) : palynologie

From 1993 to 1999, 216 samples have been collected for pollen analysis as excavations were carried out in the Saint-Vallier site. They concern the whole layers of sediments. Few samples contain pollen grains. Because of oxidation, or bad accumulation, or conservation conditions, pollen is rare. Statistics calculation is then generally impossible. In spite of that, interesting qualitative data are available. Most of the results obtained concern the sediments close to LD3 (« banc durci 3 ). A coprolite of Hyaenideae found by Jean Viret in the 1950s and belonging to the LD3 has been analysed too. It yields well-preserved pollen grains that confirm the other results. They indicate temperate climatic conditions: fresh below the LD3 (conifers dominant: Pinus, Cedrus, Picea, Abies), and warmer above, at the bone-bearing horizon (broad leaved trees, Quercus and Platanus among them). The spectrums indicate both forest environment and open landscape with heliophilous trees and herbs.

A LATE QUATERNARY PALEOENVIRONMENTAL SEQUENCE FROM DOR, CARMEL COASTAL PLAIN, ISRAEL

Abstract The 10.5 m deep “D-Dor” core was taken at Dor (Tantura Lagoon), on the Carmel coastal plain, Israel. The established chrono-stratigraphic sequence (based on x-ray radiographs, and both luminescence and radiocarbon dating) covers the last about 26,000 years. It provides the paleoenvironmental framework for the transition from hunter–gathering to agriculture in the Levant. Three clay units were identified, overlying kurkar (calcareous sandstone) and covered by 6.3 m of sand. The bottom clay unit is a paleosol. Pollen was not preserved in this unit. Gray clay (the top of which was dated to about 12,000 cal. YBP) was deposited, overlying the paleosol, in a wetland environment. Pollen was preserved only in the upper part of this unit. It indicates a slightly drier climate than today's, probably correlative with the Younger Dryas. At the beginning of the Holocene, between 10,300 and 9,550 cal. YBP, a new marsh originated, depositing dark clay. High concentrations of well-preserved pollen allowed the re...

Paleoecology of a Middle Wisconsin Deposit from Southern California

Analysis of a buried deposit in the Diamond Valley of southern California has revealed well-preserved pollen, wood, and diatom remains. Accelerator mass spectrometry dates of 41,200±2100 and 41,490±1380 14C yr B.P. place this deposit in marine isotope stage 3. Diatoms suggest a shallow lacustrine environment. Pollen data suggest that several plant communities were present near the site, with grassland, scrub, chaparral, forest, and riparian communities represented. Comparison with modern pollen suggests similarities with montane forests in the nearby San Bernardino and San Jacinto ranges, indicating vegetation lowering by at least 900 m elevation and temperatures 4°–5°C cooler than today. An increase in high-elevation conifer pollen documents climatic cooling near the profile top. Early-profile diatoms are typical of warm water with high alkalinity and conductivity, whereas later diatoms suggest a higher flow regime and input of cooler water into the system. We suggest that the sequence is part of the cooling phase of an interstadial Dansgaard–Oeschger cycle. Records of the middle Wisconsin period are rare in southern California, but the Diamond Valley site is similar to records from Tulare Lake in the San Joaquin Valley and the ODP Site 893A record from Santa Barbara Basin. It is probable that the Diamond Valley assemblage is a local expression of a vegetation type widespread in the ranges and basins of southwestern California during the middle Wisconsin.

Palynology of the Peace Creek site, Polk County, Florida

Research Article| June 01, 2001 Palynology of the Peace Creek site, Polk County, Florida Barbara C.S. Hansen; Barbara C.S. Hansen 1Limnological Research Center, University of Minnesota, 220 Pillsbury Hall, 310 Pillsbury Drive, S.E., Minneapolis, Minnesota 55455, USA Search for other works by this author on: GSW Google Scholar Eric C. Grimm; Eric C. Grimm 2Research and Collections Center, Illinois State Museum, 1011 East Ash Street, Springfield, Illinois 62703, USA Search for other works by this author on: GSW Google Scholar William A. Watts William A. Watts 3Department of Botany, Trinity College, Dublin 2, Ireland Search for other works by this author on: GSW Google Scholar Author and Article Information Barbara C.S. Hansen 1Limnological Research Center, University of Minnesota, 220 Pillsbury Hall, 310 Pillsbury Drive, S.E., Minneapolis, Minnesota 55455, USA Eric C. Grimm 2Research and Collections Center, Illinois State Museum, 1011 East Ash Street, Springfield, Illinois 62703, USA William A. Watts 3Department of Botany, Trinity College, Dublin 2, Ireland Publisher: Geological Society of America Received: 27 Sep 1999 Revision Received: 09 May 2000 Accepted: 01 Sep 2000 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2001) 113 (6): 682–692. https://doi.org/10.1130/0016-7606(2001)113<0682:POTPCS>2.0.CO;2 Article history Received: 27 Sep 1999 Revision Received: 09 May 2000 Accepted: 01 Sep 2000 First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Barbara C.S. Hansen, Eric C. Grimm, William A. Watts; Palynology of the Peace Creek site, Polk County, Florida. GSA Bulletin 2001;; 113 (6): 682–692. doi: https://doi.org/10.1130/0016-7606(2001)113<0682:POTPCS>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Peace Creek site in the central Florida Peninsula is a sinkhole completely filled with sediment. The basal ∼50 m of an ∼70- m-long core contains well-preserved pollen. The regular occurrence of Pterocarya and other regionally extinct taxa indicates a late Neogene age. Geological data place the age in the Pliocene, and high sea levels during the middle Pliocene argue for a late Pliocene age. The most probable time of formation and infilling is in the late Pliocene, after 2.8 Ma, corresponding with the onset of significant Eurasian and North American glaciation and lower sea levels. In addition to Pterocarya and Sciadopitys, well- known indicators of late Neogene pollen assemblages from the Atlantic coastal region, we identify cf. Ginkgo and cf. Dacrydium for the first time from Neogene sediments in eastern North America (cf. here indicates a type that is similar in morphology to an extant family, genus, or species). However, these regionally extinct types are rare, and the overall pollen assemblage is quantitatively similar to late Holocene assemblages from Florida and quite distinct from late Pleistocene glacial stage assemblages. A rich and diverse aquatic pollen assemblage indicates that a shallow, fresh- water wetland occupied the sinkhole throughout the time of deposition. Three cycles having a long Pinus phase and a short Quercus phase characterize the upland pollen assemblage. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Plant remains, alluvial chronology, and cave speleothem isotopes indicate abrupt Holocene climatic change at 6 ka in midwestern USA

Sediments along 1st–5th-order streams in Midwestern USA contain excellent records of abrupt climatic change in the Holocene. Cutbank exposures provide “snapshots” of areal paleovegetation based on assemblages of well-preserved pollen and plant macrofossils; when these sites are radiocarbon dated and arranged chronologically, a detailed picture of Holocene vegetational change emerges that is consistent with regional patterns. Lithologically distinct alluvial sediments and periods of rapid change from aggradation to entrenchment occur at intervals of rapid vegetational change, and are coeval with changing values of carbon isotopes from both cave speleothems and stream alluvium, indicating that climate is the major forcing function.

Palaeocarpinus aspinosa Sp. Nov. (Betulaceae) from the Paleocene of Wyoming, U. S. A.

A new species of Palaeocarpinus Crane (Betulaceae) is recognized from the Paleocene of southwestern Wyoming that extends the concept of the genus to include fruits with nonspiny bracts. Fruits of P. aspinosa sp. nov. are borne in pairs on an elongate infructescence, each fruit enclosed by two equal bracts that are entire-margined to serrate but not dissected or spiny. Associated staminate catkins contain well-preserved pollen that is not only triporate, but commonly tetra- to pentaporate. The pollen exine is tectate-granular, with spinulate ornamentation. Co-occurring betulaceous leaves are similar to those of P. joffrensis Sun et Stockey from Canada and P. orientalis from China and to leaves of extant Corylus. The associated infructescences, leaves, and staminate inflorescences with in situ pollen facilitate detailed reconstruction of this extinct species and provide a clearer understanding of the genus and its relation to extant genera. Palaeocarpinus aspinosa, with its nonspiny fruit bracts and multiporate pollen, adds to our understanding of the morphological diversity present in this widespread early Tertiary genus. The nondissected bracts may have been effective for wind and water dispersal whereas other species with spiny burrlike bracts may have been dispersed by furry animals.

Secale Cereale Pollen: Botanical Reasons for Variability in the Quality of Allergenic Extracts

Abstract Three Secale cereale pollen batches, harvested by different procedures and supplied by manufacturers from different countries, were parallelly incubated in phosphate buffer saline, pH 7. 4. The extracts obtained showed differences both in proteic and allergenic composition. To analyze the reasons for this variability we have studied the way in which proteins and allergens leave the pollen during the extraction procedure. The results show that well-preserved pollen grains release their components in accordance with the botanical events that occur in Secale cereale pollen when it is rehydrated. Alterations produced in the pollen during manufacturing procedures cause differences in protein emission patterns, affecting the final composition of the allergenic extract. Moreover, although well-preserved pollen batches released their proteins in a similar way, we have detected slight differences in the electrophoretical mobility. Comparable allergens were correactives, but IgE from the patients studied showed a different affinity to them.