University of Leicester
Browse
monkeyhair.pdf (2.94 MB)

Fossilization of the eocene "monkeyhair" laticifer tree from Geiseltal, Germany: A deeper understanding using micro-ct and pyrolysis gc/ms

Download (2.94 MB)
journal contribution
posted on 2021-04-20, 15:14 authored by VE MCCOY, A BOOM, O OLIVERWINGS, T WAPPLER, CC LABANDEIRA, CT GEE
Although the fibrous plant material called Affenhaar from the middle Eocene lignites of Geiseltal in Germany has been repeatedly studied for over 172 years, modern imaging and chemical analyses have enabled a deeper understanding of its chemical composition and preservation within the parent plant. Known in English as "monkeyhair,"the fibrous material represents a very rare case of fossil laticifers, the latex-bearing ducts of plants. Here we use high-resolution X-ray microcomputed tomography (micro-CT) for the first time to elucidate the anatomy of tissues and their differential degradation within the monkeyhair tree. Even in large, fairly intact stem axes, the center cylinder of secondary xylem inside the trunks or branches is completely absent, presumably due to diagenetic degradation. Nevertheless, there is a moderately well-preserved outer layer of bark and mats of excellently preserved laticifers in the extraxylary zone beneath the bark. Previous chemical analyses revealed that the latex in these laticifers was dominated by natural rubber (cis-1,4-polyisoprene), but also included various triterpenoids. These fossil laticifers also contained large amounts of organic sulfur, suggesting the rubber may have been naturally vulcanized. Pyrolysis GC/MS is also applied to the fossil laticifers for the first time to identify the organic sulfur constituents of this ancient latex. The chemical analysis yields 12 major sulfur compounds, mostly thiophenes, consistent with vulcanized rubber. The vulcanization of these laticifers most likely occurred during early diagenesis, before the degradation of the wood, at low temperatures, and may have been facilitated with other compounds that served as accelerators, activators, and fillers.

History

Citation

PALAIOS (2021) 36 (1): 1–14.

Author affiliation

School of Geography, Geology and the Environment

Version

  • AM (Accepted Manuscript)

Published in

Palaios

Volume

36

Issue

1

Pagination

1 - 14

Publisher

Society for Sedimentary Geology

issn

0883-1351

eissn

1938-5323

Acceptance date

2020-12-01

Copyright date

2021

Available date

2021-04-20

Language

en

Usage metrics

    University of Leicester Publications

    Categories

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC