Even a grade school-age Tyrannosaurus rex was imposing: 17 feet long with a massive jaw and those signature deadly, jagged teeth.

University of Kansas paleontologist David Burnham leads a team now unearthing several young T. rex fossils in the Hell Creek region of Montana, an extraordinarily rare find that promises to shed light on how these creatures grew and developed some 67 million years ago. Burnham, who heads the Vertebrate Paleontology Laboratory at the KU Biodiversity Institute, discusses the discovery and his work in the field excavating the remains. He brings quality casts of actual T. rex specimens—baby, juvenile, and adult teeth and skull bones—for display.

Burnham was a key collaborator on the exhibition Dinosaurs Revealed: Journey Across America, on display through January 6, 2019, at Kansas City’s Union Station.