The use of lacquer (nitrocellulose) for the coating and preservation of fossil leaf compressions

Abstract

Cuticular features and details of fine venation are now widely relied upon in systematic and phylogenetic studies of fossil plants. Where fossil leaves are robust or adherent to the matrix, such features may be readily available, but should the remains be fragile and subject to damage or loss, it may be necessary to preserve their integrity immediately following recovery and during transport. Clays, shales, and fossil leaf compressions are particularly vulnerable to the drying environment; fossil specimens are commonly damaged or entirely lost due to spalling, cracking, and shrinking of the clays or due to exfoliation of the organic film caused by differential drying. In an attempt to eliminate these problems, a technique using a mixture of nitrocellulose lacquer and acetone to coat fossil leaf compressions was developed for use on freshly excavated specimens under a wide range of climatic conditions (subfreezing to warm, dry or wet) while in the field. Many other preservational techniques exist, but they are typically complex, expensive, time consuming, destructive, or were developed for use in a laboratory setting.