Expeditions to a remote area of Yukon, Canada, have uncovered a 120-million-year-long geological record of a time when land plants and complex animals first evolved and ocean oxygen levels began to ...

Back in 260 million B.C., the mammal-like creature known as Tiarajudens eccentricus looked as fearsome as any predator —possessing rows of teeth that went all the way back into its palate, with two ...

Fig.1: Tempo and mode in the body size evolution of Cambrian-Ordovician trilobites. Changes in maximum size (red) and mean size (blue) for each time slice, with lines and shading representing the mean ...