When Plants First Conquered the Land

Scientists have long sought to answer the question of just when animals rst moved from water onto land. But before animals could make the move, they needed something to justify it, namely, a food source. Two earth scientists now suggest a date of 480 million years ago.

In the journal Science, Paul K. Strother (Boston College) and Clinton Foster ( e Australian National University) describe microscopic fossil spores from the early Ordovician Period that they’ve discovered in Canning Basin of Australia. e spores seem to be from embryophytes or true land plants that had finally evolved beyond their algal ancestors. ( is transition, by the way, was no mean feat. Terrestrial plants need coated walls to prevent death from desiccation in the open air as compared to plants continually bathed in aquatic environments.)

While earlier paleontologists were looking for big, whole fossil plants and declared a “gap” in the fossil record when they found none, Strother and Foster have dug deeper to look into the rock itself , with the aid of microscopes, to nd evidence not visible to the naked eye. Increasingly, it seems, the future of paleontology lies in genetic analysis, microbiology and all things tiny yet true!