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We reconstructed fluctuations in the East Asian monsoon and vegetation in the Japan Sea region since the middle Pliocene based on pollen data obtained from sediments collected by the Integrated Ocean Drilling Program off the southwestern coast of northern Japan. Taxodiaceae conifers Metasequoia and Cryptomeria and Sciadopityacere conifer Sciadopitys are excellent indicators of a humid climate during the monsoon. The pollen temperature index (Tp) can be used as a proxy for relative air temperature. Based on changes in vegetation and reconstructed climate over a period of 4.3 Ma, we classified the sediment sequence into six pollen zones. From 4.3 to 3.8 Ma (Zone 1), the climate fluctuated between cool/moist and warm/moist climatic conditions. Vegetation changed between warm temperate mixed forest and cool temperate conifer forest. The Neogene type tree Carya recovered under a warm/moist climate. The period from 3.8 to 2.5 Ma (Zone 2) was characterized by increased Metasequoia pollen concentration. Warm temperate mixed forest vegetation developed under a cool/moist climate. The period from 2.5 to 2.2 Ma (Zone 3) was characterized by an abrupt increase in Metasequoia and/or Cryptomeria pollen and a decrease in warm broadleaf tree pollen, indicating a cool/humid climate. The Zone 4 period (2.2–1.7 Ma) was characterized by a decrease in Metasequoia and/or Cryptomeria pollen and an increase in cool temperate conifer Picea and Tsuga pollen, indicating a cool/moist climate. The period from 1.7 to 0.3 Ma (Zone 5) was characterized by orbital-scale climate fluctuations. Cycles of abrupt increases and decreases in Cryptomeria and Picea pollen and in Tp values indicated changes between warm/humid and cold/dry climates. The alpine fern Selaginella selaginoides appeared as of 1.6 Ma. Vegetation alternated among warm mixed, cool mixed, and cool temperate conifer forests. Zone 6 (0.3 Ma to present) was characterized by a decrease in Cryptomeria pollen. The warm temperate broadleaf forest and cool temperate conifer forest developed alternately under warm/moist and cold/dry climate. Zone 2 corresponded to a weak Tsushima Current breaking through the Tsushima Strait, and the beginning of orbital-scale climatic changes at 1.7 Ma during Zone 5 corresponded to the strong inflow of the Tsushima Current into the Japan Sea during interglacial periods (Gallagher et al., 2015). [ABSTRACT FROM AUTHOR]

Extinction risk in the modern world and extinction in the geological past are often linked to aspects of life history or other facets of biology that are phylogenetically conserved within clades. These links can result in phylogenetic clustering of extinction, a measurement comparable across different clades and time periods that can be made in the absence of detailed trait data. This phylogenetic approach is particularly suitable for vertebrate taxa, which often have fragmentary fossil records, but robust, cladistically-inferred trees. Here we use simulations to investigate the adequacy of measures of phylogenetic clustering of extinction when applied to phylogenies of fossil taxa while assuming a Brownian motion model of trait evolution. We characterize expected biases under a variety of evolutionary and analytical scenarios. Recovery of accurate estimates of extinction clustering depends heavily on the sampling rate, and results can be highly variable across topologies. Clustering is often underestimated at low sampling rates, whereas at high sampling rates it is always overestimated. Sampling rate dictates which cladogram timescaling method will produce the most accurate results, as well as how much of a bias ancestor-descendant pairs introduce. We illustrate this approach by applying two phylogenetic metrics of extinction clustering (Fritz and Purvis's D and Moran's I) to three tetrapod clades across an interval including the Permo-Triassic mass extinction event. These groups consistently show phylogenetic clustering of extinction, unrelated to change in other quantitative metrics such as taxonomic diversity or extinction intensity. [ABSTRACT FROM AUTHOR]

Abstract: The early Cenozoic Chickaloon Formation is the main coal-bearing sequence in south-central Alaska. Coal and associated plant macrofossils are well exposed in the Eska, Premier, and Jonesville Coal Groups in the Wishbone Hill District. There is a striking variation in the degree and mode of preservation of fossil trees in a vertical sequence through these coal groups. We examined the wood taxonomy, mineralogy, and geochemistry to elucidate potential cause(s) for these differences. The wood anatomy indicates that the wood is all assignable to the Cupressaceae (Taxodiaceae s.str.) and assignable to the form genus Taxodioxylon Hartig emend. Gothan. However, we found no significant variation in the taxonomy of the wood between stratigraphic layers. The wood generally becomes better preserved in the Jonesville Coal Group. Wood from the stratigraphically lower Premier Coal Group exhibits greater plastic deformation and contains less well-preserved wood anatomical features. The wood from the overlying Jonesville Coal Group retains most of its original morphology, but has suffered from brittle fracture. The geochemistry and mineralogy of the wood follow a pattern that corresponds to the degree of preservation. The less well-preserved wood tends to have a higher concentration of iron carbonate minerals (e.g., siderite and ankerite), whereas the better preserved wood contains more calcium carbonate or silica. All evidence points to rapid permineralization of the original wood, although the least well-preserved wood shows evidence of greater organic matter decomposition than the better preserved wood. The wood taxonomy and mode of preservation of wood from the upper part of the Chickaloon Formation is similar to wood from coeval fossil forests that developed at higher (polar) paleolatitudes. [ABSTRACT FROM AUTHOR]

Abstract: In summer 2007 sixteen Taxodium tree trunks were found in situ standing position in the Bükkábrány open cast mine. The fossil trees were exposed during the excavation of the overburden layers of the Bükkalja Lignite Formation (BL). The Bükkábrány discovery is a global novum because the trees are very well preserved but not fossilized that makes the most detailed and direct analysis feasible. In spite of the 7–8million years passed, the actual site and the host formation is rather intact, lacking tectonic deformations, deeper burial and/or dewatering during uplift. Organic petrology of tree trunks and sedimentology of the overburden sands are the subjects of this study. The extremely good preservation of fossil trunk tissues, presence of high amount of cellulose and moisture content along with the slightly gelified state of the wood and the lack of deformation indicate that there was only limited alteration during the early diagenesis. Chemical investigation of standing trunks fossil driftwood nearby the Late Miocene trees, and the fossil woods in the underlying lignite have revealed that their cellulose and total phenol concentrations were significantly lower than in intact recent trees, applied for reference. Yet their preservation levels were quite high, also proving that the chemical degradation of the fossil wood tissues had not been taken place extensively in the mire and the trees remained exceptionally well preserved. Sudden burial of the trees by strand plain sand beds indicates flooding by heavy storms or tsunamis, which interrupted and terminated the peat formation and preserved the trunks from later oxidation and biodegradation. [Copyright &y& Elsevier]

Abstract: Two exposures in Jylland, Denmark, encompassing beds of latest Oligocene to earliest Miocene age (latest Chattian–early Aquitanian) yielded well-preserved palynofloras. The assemblages indicate that Jylland was covered by extensive Taxodiaceae swamp forests in the mid-Cenozoic. Besides a Taxodiaceae–Cupressaceae association, which was overwhelmingly dominant, other common plants in this habitat were Alnus, Nyssa, Betula, Salix, Cyrilla and Myrica. Most of the trees and shrubs are well adapted to swamps and thrive under more or less flooded conditions in modern bald cypress swamps of the southeastern North America. Vegetation composition indicates that a warm–temperate climate prevailed in Denmark during the Oligocene–Miocene transition. According to calculations using the Coexistence Approach, the mean annual temperature during this time span ranged from 15.6 to 16.6°C. An increase to 16.5–21.1°C is inferred from the palynoflora in the upper part of the section. The earlier, cooler period possibly reflects global cooling associated with the Mi-1 glaciation event at the Oligocene–Miocene boundary. No data from the very coldest part of the Mi-1 event has been recorded, as this is represented by a gravel layer (representing a hiatus) in the lowermost part of the studied succession. The length of the missing time is not known precisely, but is probably in the order of some hundred thousand years. Correlation with the well-established chronostratigraphic and sequence stratigraphic framework for the studied succession reveals that the most distinctive change in palynoflora probably reflects a shift in depositional facies (due to an increase in sea level) rather than direct climatic change. The sea-level rise is herein interpreted to be eustatic and related to melting of Antarctic ice caps at the end of the Mi-1 glaciation event. [Copyright &y& Elsevier]

Abstract: Mummified foliage, seeds and cones of Glyptostrobus europaeus (Brongniart) Unger (Taxodiaceae, or Cupressaceae s. l.) are very common within muddy sediments embedding large arboreal stumps in several Pliocene localities of northern and central Italy. Recent investigations in one of these fossil forests, which crops out 20 km North of Turin (NW Italy), in the bed of the Stura di Lanzo river, showed that the wood anatomy is also diagnostic for the genus Glyptostrobus, since the wood-type is characteristic of the recently defined morphospecies Glyptostroboxylon rudolphii Dolezych and Van der Burgh. Although connection between stumps, trunks and twigs has never been observed, the Stura di Lanzo Fossil Forest (FF) provides a very favourable condition to reconstruct the ancient taxodiaceous “whole-plant”, because there is only one common conifer type in the site''s macrofossil record. The autochthonous burial of the foliage is indicated by the high frequency of randomly oriented shoots with attached cones. Therefore it is demonstrated that the plant bearing the Glyptostrobus europaeus foliage, also produced stumps and trunks with the Glyptostroboxylon rudolphii wood-type. The numerous and huge stumps of this site, and associated trunks, provide an excellent example of what was the size and habit of the Glyptostrobus europaeus “whole-plant”. [Copyright &y& Elsevier]