In our quest to complete a phylogeny for all living birds, extinct species play a big role as well. Fossils provide calibrations to date the tree. But, they also provide sometimes unexpected insight into how each group of birds evolved, including were they originated and how they changed over time. As our team has advanced our understanding of extant passerine (perching bird) phylogeny, we have also been delving into the surprising past of this hyper-diverse group. Modern passerines include many familiar backyard birds such as sparrows, chickadees, and crows – and with over 6000 extant species represent more than half of present day bird diversity. Open Wings paleontologist Daniel Ksepka, working with colleagues Lance Grande of the Field Museum and Gerald Mayr of the Senckenberg Research Institute, recently identified two new extinct bird species that were the first to evolve finch-like beaks. Fossils of the new species, named Eofringillirostrum boudreauxi and Eofringillirostrum parvulum, were discovered in Wyoming and Germany. The exquisite fossils date to 50 million years ago, a time when both regions were covered by subtropical forests. Despite their dominance of many modern ecosystems, passerines have a very sparse fossil record. The two Eofringillirostrum species appear to have been […]