Sixty six million years ago, sea monsters really existed. They were mosasaurs, huge marine lizards that lived at the same time as the last dinosaurs. Growing up to 12 meters long, mosasaurs looked like a Komodo dragon with flippers and a shark-like tail. They were also wildly diverse, evolving dozens of species that filled different niches. Some ate fish and squid, some ate shellfish or ammonites.
Continued greenhouse gas emissions risk triggering climate tipping points. These are self-sustaining shifts in the climate system that would lock-in devastating changes, like sea-level rise, even if all emissions ended.
After three years of planning, five expeditions and a two-week trek through dense jungle, scientists have reached the tallest tree ever found in the Amazon rainforest, a towering specimen the size of a 25-storey building.
U.S. researchers say the number of gray whales off western North America has continued to fall over the last two years, a decline that resembles previous population swings over the past several decades.