Unknown Giant Once Dominated Land 400 Million Years Ago ...

Add Yahoo as a preferred source to see more of our stories on Google. An artist's impression of what Prototaxites may have looked like 400 million years ago. - Matt Humpage Some 400 million years ago, ...

(CNN) — Some 400 million years ago, long before dinosaurs or even trees had evolved, an enigmatic organism towered over the landscape like a prehistoric monolith. Now, new research makes the case that ...