Ancient Eggshells Hold Clues to Plant Evolution on a Warmer Earth

Some periods in Earth's history are so different from our own that they may as well belong to another planet. Many people are interested in the age of dinosaurs or the Ice Ages, but it is an intermediate world, the Miocene Epoch—a sort of "in-between" world, geologically speaking: less recent than mammoths and stone tools, but not the deep past of dinosaurs—that many scientists find interesting.