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Early Cretaceous flora of Hungary and its palaeoecological significance

100%

Barale G. , Barbacka M. , Philippe M.

Acta Palaeobotanica

2002

tom 42

nr 1

Xenoxylon synecology and palaeoclimatic implications for the Mesozoic of Eurasia

100%

Oh C. , Philippe M. , Kim K.

Acta Palaeontologica Polonica

2015

tom 60

nr 1

The distribution of fossil wood genera has been demonstrated to be an effective proxy for Mesozoic terrestrial climates. In this study, we investigated the phytocoenoses, which were associated with Xenoxylon confirmed to be a marker for a cool and/or wet climate in a boreal hemisphere (i.e., Xenoxylon-phytocoenoses) during the Mesozoic, using specimens of fossil wood. It was confirmed that Xenoxylon co-occurs more often with some wood genera than with others. For example, Protocedroxylon, a wood that is most likely related to the Pinaceae, is the genus most often associated with Xenoxylon-phytocoenoses. Although Taxodioxylon is also found in Xenoxylon-phytocoenoses, it is not found, however, as consistently as Protocedroxylon. The distribution and diversity of Xenoxylon-phytocoenoses changed throughout the Mesozoic. During the Late Triassic and Late Cretaceous, Xenoxylon-phytocoenoses had low diversity and were restricted to higher palaeolatitudes during the Late Cretaceous. However, during the Early to Middle Jurassic, Xenoxylon- phytocoenoses were distributed much farther south, while their diversity concomitantly increased sharply. From the Late Jurassic to the Early Cretaceous, the distribution of Xenoxylon-phytocoenoses moved northward in Europe and even more so in East Asia. The changes in the distribution of Xenoxylon-phytocoenoses are in agreement with changes in both global and regional climates. Our results also demonstrated that, within the Xenoxylon distribution range, the corresponding phytocoenoses were differentiated along a latitudinal gradient and according to the global climate change patterns during the Mesozoic.

Perylene and other terrestrial biomarkers identified in the Middle Jurassic conifer wood and their palaeoenvironmental significance

88%

Smolarek J. , Marynowski L. , Bechtel A. , Philippe M. , Simoneit B. R. T.

Geology, Geophysics and Environment

2014

tom Vol. 40, no. 1

129

The occurrence of perylene in the Middle Jurassic fossil wood from Poland is described, along with its correlation with unsubstituted polycyclic aromatic hydrocarbons (PAHs) as well as cellulose content. Perylene is especially common in immature/low maturity organic matter (OM), largely of terrestrial origin (e.g. Louda & Baker 1984, Jiang et al. 2000, Grice et al. 2009). It has been found in diverse recent environments, such as marine and terrestrial sediments, including peats, as well as ancient deposits, including brown coal and hard coal, crude oil and sedimentary rocks (review in Marynowski et al. 2013). Here we link perylene, a product of wood-degrading fungi, to conifer biomarkers in fossil wood material of different ages. Middle Jurassic wood remnants were of relatively low maturity (ca. 0.2-0.4% vitrinite reflectance Rr), had excellent preservation of biomarkers and biomolecules and generally good preservation of anatomical structures due to early diagenetic mineralisation. The results from described (most taxonomically defined) fossil wood fragments demonstrated a negative correlation between the concentration of perylene and those of generally typical conifer biomarkers (e.g. cadalene, dehydroabietane, simonellite and retene). We defined a conifer wood degradation index as: CWDI = perylene / (perylene + cadalene + retene + simonellite + dehydroabietane); and observed a wide range of values (0.001 for less degraded wood to 0.95 for highly degraded samples). We determined similar δ13C values for perylene from the fossil wood samples (from -26.4% to -27.8%), whereas the values for the conifer biomarkers were slightly higher and varied from -25.6% to -26.6%. In contrast, pyrene was depleted in 13C (from -27.5% to -28.2%). The carbon isotope values of perylene are consistent with an origin from wood-degrading fungi.

Palaeobiogeographical implications of the first fossil wood flora from the Jurassic of Turkey

88%

Akkemik U. , Kandemir R. , Philippe M. , Gungor Y. , Koroglu F.

Acta Palaeontologica Polonica

2022

tom 67

nr 3