Fossil cutin of Macroneuropteris scheuchzeri (Late Pennsylvanian seed fern, Canada)

D`ANGELO J A; LYONS P C; MASTALERZ M; ZODROW E L

INTERNATIONAL JOURNAL OF COAL GEOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 105 p. 137 - 140

0166-5162

Cutin polymer from compression-preserved specimens of Macroneuropteris scheuchzeri (seed fern, Medullosales) is recorded for the first time. Specimens of basal Cantabrian strata, Sydney Coalfield, Canada, exhibit excellent preservation. The cutin was concentrated by Schulze?s process by time-controlled oxidation reaction. Reported are functional-group changes monitored via semi-quantitative Fourier transform infrared (FTIR) spectrometry as a function of cutin concentration in Schulze?s solution. Distinct features of the cutin spectrum include intense peaks of ester C=O groups, centered at 1730-1715 cm-1, and aromatic C=C absorption bands at 1640-1645 cm-1. Cutin is characterized and differentiated from the corresponding M. scheuchzeri cuticle mainly by the comparatively higher values of CH2/CH3, C=O/C=C, and the very low values of CHal/C=O and C=C contribution. Cutin data compare with available semi-quantitative FTIR data from modern L. esculentum cutin, particularly emphasized by CHal/C=O ratios whose low value of ca. 0.9 indicates a similar cross-linking degree of the polymeric structure for the fossil and extant taxa.