Geochemical Fingerprints of Ginkgoales Across the Triassic-Jurassic Boundary of Greenland

Premise of research. Geochemical fingerprinting fossil plants is a relatively new research field complementing morphological analyses and providing information for paleoenvironmental interpretations. Ginkgoales contains single extant species but was diverse through the Mesozoic an excellent target biochemical analyses.Methodology. Cuticles derived from fresh fallen autumn leaves Ginkgo biloba seven ginkgoalean leaf taxa, one seed fern taxon, two taxa with bennettitalean affinity were analyzed by infrared (IR) microspectroscopy at D7 beamline in MAX IV synchrotron laboratory, Sweden. The material derives Triassic Jurassic successions Greenland. Spectral data sets compared evaluated hierarchical cluster analysis (HCA) principal component performed on vector-normalized, first-derivative IR absorption spectra.Pivotal results. spectra all reveal signatures that clearly indicate presence organic compounds. Spectra G. aliphatic chains, aromatic ester carbonyl functional groups polymer cutin other waxy compounds, polysaccharides. Interestingly, both specimens carboxyl/ketone molecules, suggesting chemical alterations during initial stages decomposition are preserved fossilization. Two major subclusters identified HCA spectra.Conclusions. Consistent signatures, specific each taxon present cuticles, sufficient molecular content key regions to reflect plants’ original signatures. compounds initiated as soon shed, loss proteins increased compound production leaves. We further show groupings combination phylogeny environmental conditions related end-Triassic event.