Thirty-three years (1986–2019) of fossil plant cuticle studies using transmission electron microscopy: A review

Although the cuticle is a very thin layer of a few micrometers, it is one of the main remains found among fossil plants. Apparently very fragile, ultrathin cuticle sections of few dozen nanometers thick are studied by using TEM studies and statistical measurements. The ultrastructure details yielded are of significance not only for taxonomy, but also for paleoenvironment and evolution of fossil plant. After an historical introduction and a review of the methods to obtain and observe the ultrathin sections, although data are still not enough numerous, detailed information and interesting facts of cuticle ultrastructure emerge from the studied plant groups. This paper gives a review of the main results of transmission electron microscopy -TEM- of fossil plant cuticles since the pioneering study 33 years ago.