Weber, Charles E.
March 18, 2013
angiosperm, deciduous, dicotyledon, glaze ice, Ontong Java Plateau, hard wood
Angiosperm deciduous dicotyledon trees have had much more success in surviving in glaze ice areas than other types of trees because of less branch breakage. They started to become established in North American subarctic regions in the Paleocene and were fully established before the Eocene closed. They probably descended largely from subtropical trees, those that had evolved hard wood because of termites. I suspect that they may have evolved the precursor deciduous genes on a now submerged Southwestern Pacific continent, the Ontong Java Plateau, probably as early as the Permian, as a monsoon area adaptation. Their seeds were probably carried to the mainland across volcanic islands on the feet and in the crops of water birds.