Zosterophyll

The zosterophylls are a group of extinct land plants that first appeared in the Silurian period. The taxon was first established by Banks in 1968 as the subdivisionZosterophyllophytina; they have since also been treated as the divisionZosterophyllophyta or Zosterophyta and the class or plesionZosterophyllopsida or Zosteropsida. They were among the first vascular plants in the fossil record, and had a world-wide distribution. They were probably stem-grouplycophytes, forming a sister group to the ancestors of the living lycophytes. By the late Silurian (late Ludlovian, about 420 million years ago) a diverse assemblage of species existed, examples of which have been found fossilised in what is now Bathurst Island in ArcticCanada.