The rise of dinosaurs coincided with environmental changes driven by major volcanic eruptions over 230 million years ago, a new study reveals.

Ice melange, a slushy mixture of snow and ice chunks, can heal large rifts in Antarctica's ice shelves. Researchers at the University of California, Irvine and NASA's Jet Propulsion Laboratory found that a thinning of ice melange may have enabled a Delaware-sized iceberg to break off from the Larsen C ice shelf in 2017. A new paper in PNAS has the scientists' analysis of the dynamics behind large iceberg calving events.

Geologists have been baffled by perforations in an Australian quartzite (rock), identical in shape to burrows made in sands by crustaceans; the original sandy sediment is a billion years older than the oldest known animals. An international team of scientists has now resolved the mystery.

Nine articles explore the impacts of ancient human societies on tropical ecosystems, revealing the importance of incorporating the paleosciences, social sciences and indigenous traditional knowledge in the development of solutions for contemporary environmental challenges

New special edition of the Proceedings of the National Academy of Sciences showcases multidisciplinary approaches to exploring human impacts on tropical forests and their associated earth systems.