A wave of new research is forcing paleontologists to reconsider a basic question about life on Earth: when did the first mass ...
Many of their descendants—modern birds—are currently threatened by extinction, with hundreds of species at risk due to human activity. This article explores the major extinction events that influenced ...
A pair of Sacabambaspis fish, around 35 cm in length, which had distinct, forward-facing eyes and an armored head. No fossils of animals like Sacabambaspis from after the Late Ordovician Mass ...