Thoughts on the Early Lycopsids and Zosterophylls

Abstract

Morphological, anatomical, and reproductive characteristics of the modern lycopsids are of great value in tracing the ancient lineage of the group. The sporangium is the principal character: lack or misinterpretation of it in fossil specimens places an investigator in a predicament. An informed choice of a group of characters must be made from all those that remain. There are, of course, pitfalls and the defining characters of fossil species of the lycopsids have become confused. Differences in ontogeny of sporangia in early land plants are suggested as a way of separating the early rhyniophytoids with terminal, fusiform, indehiscent sporangia from the cooksonioid plants with terminal, globular or reniform, dehiscent sporangia (...)