OTTO, ANGELIKA*, WILLIAM C. REMBER, AND BERND R. T. SIMONEIT. 1,3 College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331; 2 College of Mines and Earth Resources, University of Idaho, Moscow, ID 83444. - Chemical characteristics of five fossil conifer species from the Miocene Clarkia Flora, Emerald Creek, Idaho, USA.
The excellent preservation of plant macrofossils of the Miocene
Clarkia flora, Emerald Creek, Idaho, USA, allowed the analysis of the
extractable chemical compounds of five fossil conifer species. Foliar
branches and cones of Cunninghamia chaneyi, Glyptostrobus oregonensis
and Taxodium dubium (Taxodiaceae) and foliar branches of Metasequoia
occidentalis (Taxodiaceae) and Calocedrus sp. (Cupressaceae) have been
extracted with organic solvents, and the extracts have been analyzed
as is and derivatized using gas chromatography-mass spectrometry.
Generally, the extracts from foliar branches and cones of the same
species showed similar extract patterns while the extracts from
different species yielded different extract compositions. Several
sesqui- and diterpenoids that probably originate from the resins have
been identified. Most of the terpenoids have been degraded during
diagenesis, but some compounds have been preserved unaltered. An
aliphatic alcohol, n-nonacosan-10-ol, that occurs in the waxes of
extant conifers was present in the foliage of all investigated fossil
conifers. Furthermore, all conifer species contained the diterpenoids
ferruginol and 6,7-dihydroferruginol which are known from extant
species of Cupressaceae, Taxodiaceae and Podocarpaceae. The fossil
conifer species showed characteristic diterpenoid patterns which in
part match the compounds that have been found in related extant
species. In Taxodium dubium some terpenoids (sugiol, ferruginol
methylether, isochamaecydine) have been identified which also occur in
extant T. distichum. Glyptostrobus oregonensis contains terpenoids
similar to Taxodium dubium, but lacks ferruginol methylether.
Cunninghamia chaneyi is characterized by two diterpenoids (hinokiol,
hinokione) that have also been identified in the extracts of extant C.
lanceolata. Specific terpenoids have not been observed in the foliar
branches of Metasequoia occidentalis. Extracts of Calocedrus sp.
(Cupressaceae) contain totarol which is known from numerous extant
species of Cupressaceae and Podocarpaceae, but has been described only
from one species of the Taxodiaceae (Cryptomeria).
Key words: biogeochemistry, biomarker, Clarkia, conifers, Miocene, terpenoids