Fossil leaves from Africa have resolved a prehistoric climate puzzle—and also confirm the link between carbon dioxide in the atmosphere and global warming.
The glaciers that carved Yosemite Valley left highly polished surfaces on many of the region's rock formations. These smooth, shiny surfaces, known as glacial polish, are common in the Sierra Nevada and other glaciated landscapes.
The Colorado River's initial trip to the ocean didn't come easy, but its story has emerged from layers of sediment preserved within tectonically active stretches of the waterway's lower reaches.
A Yale-led research team has discovered a cache of embryo-like microfossils in northern Mongolia that may shed light on questions about the long-ago shift from microbes to animals on Earth.