(AP) — A Kansas fossil hunter has unearthed the remains of what is believed to be a half-grown Tyrannosaurus rex from Montana that could help fill a void in paleontologists’ understanding of the king of the dinosaurs.

Robert Detrich, of Wichita, Kan., unearthed the fossil dubbed “Baby Bob” in July in a fossil-rich area near the town of Jordan. It’s generating excitement because its femur measures about 25 inches. If all the preliminary data pans out, that would make it among the smallest T.rex specimens ever found.

Scientists say that only a handful of juvenile T.rex specimens have been discovered. And they’re eager to learn more about the years before the carnivore reached its terrifying full size of about 40 feet from head to toe.