FOSSILIZATION OF THE EOCENE “MONKEYHAIR” LATICIFER TREE FROM GEISELTAL, GERMANY: A DEEPER UNDERSTANDING USING MICRO-CT AND PYROLYSIS GC/MS

ABSTRACT Although the fibrous plant material called Affenhaar from 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 its composition preservation within parent plant. Known English as “monkeyhair,” represents very rare case fossil laticifers, latex-bearing ducts plants. Here we use high-resolution X-ray microcomputed tomography (micro-CT) first time to elucidate anatomy tissues their differential degradation monkeyhair tree. Even large, fairly intact stem axes, center cylinder secondary xylem inside trunks or branches is completely absent, presumably due diagenetic degradation. Nevertheless, there moderately well-preserved outer layer bark mats excellently preserved laticifers extraxylary zone beneath bark. Previous revealed that latex these was dominated by natural rubber (cis-1,4-polyisoprene), but also included various triterpenoids. These contained large amounts organic sulfur, suggesting may naturally vulcanized. Pyrolysis GC/MS applied identify sulfur constituents this ancient latex. The analysis yields 12 major compounds, mostly thiophenes, consistent with vulcanized rubber. vulcanization most likely occurred during early diagenesis, before wood, at low temperatures, facilitated other compounds served accelerators, activators, fillers.