The Paleozoic era's Silurian period saw animals and plants finally ... such as primitive centipedes and arachnids, the ancestors of spiders. The first true plants began to take root on land ...

The Silurian Hypothesis contemplates how long the ruins of a civilization would be detectable, on Earth or even other worlds, and if we could ever know if a world had once been inhabited by a ...

However, in 2018 two University of Cambridge scientists named their paper The Silurian hypothesis ... "This short time period ...