The Field Museum has unveiled a new specimen of Archaeopteryx, a species that may hold the key to how ancient dinosaurs became modern birds. Also, a “green glacier” of trees and shrubs is sliding across the Great Plains, burying some of the most threatened habitat on the planet.Remarkably Well-Preserved Archeopteryx Specimen UnveiledThe Field Museum in Chicago just unveiled a new specimen of one of the most important fossils ever: Archaeopteryx. It lived around 150 million years ago, and this species is famous for marking the transition from dinosaurs to birds in the tree of life.The Field Museum now has the 13th known fossil—and it may be the best-preserved one yet. So what makes this specimen so special? And what else is there to learn about Archaeopteryx?To answer these questions, guest host Sophie Bushwick talks with Dr. Jingmai O’Connor, associate curator of fossil reptiles at the Field Museum, about what makes Archaeopteryx such an icon in the world of paleontology and why they’re so excited about it.Trees And Shrubs Are Burying Prairies Of The Great PlainsIn the Flint Hills region of Kansas, the Mushrush family is beating back a juggernaut unleashed by humans — a Green Glacier of trees and shrubs grinding slowly across the Great Plains and burying some of the most threatened habitat on the planet.This blanket of shrublands and dense juniper woods gobbling up grassland leads to wildfires with towering flames that dwarf those generated in prairie fires.It also eats into ranchers’ livelihoods. It smothers habitat for grassland birds, prairie fish and other critters that evolved for a world that’s disappearing. It dries up streams and creeks. New research even finds that, across much of the Great Plains, the advent of trees actually makes climate change worse.Now a federal initiative equips landowners like Daniel Mushrush with the latest science and strategies for saving rangeland, and money to help with the work.Read more at sciencefriday.com.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.