Suberin, the hallmark constituent of bark, identified in a 45-million-year-old monkeyhair tree (Coumoxylon hartigii) from Geiseltal, Germany

Tissue and extracts

Three tissue samples from the two layers of the fossil monkeyhair tree (Fig. 1) as well as a recent control sample from the bark of Quercus suber were analyzed. The outer layer of the fossil (sample I) was interpreted as bark, the inner layer as degraded wood (sample II), and sample III as strands of laticifers. After milling the samples, they were found to be variously colored (Fig. 2). Subsequent methanolysis and acidification to pH 6 yielded dichloromethane extracts, that showed similar color for sample I (the putative fossil bark layer of the fossil monkeyhair…