Ordovician Period |
The Ordovician Period saw the evolution of the first land plants, or Embryophyta, from the green algae phylum Charophyta.
These organisms were bryophytes, which include mosses (Bryophyta), hornworts (Anthocerotophyta) and liverworts (Marchantiophyta). These plants lacked any vascular tissue (water-carrying tissues) at all and therefore could only live very close to open water. |
These organisms are haploid, (think sex cell) being either male or female and producing sperm and eggs. With the help of water, these sperm and eggs come together as a diploid sporophyte, which produces haploid spores for new plants through meiosis. |
The Ordovician landscape showing early colonization of land.