Nanotyrannus measured nearly 20 feet long and weighed about 1,500 pounds Credit: Sotheby's

Almost one year ago, paleontologists finally settled a longstanding debate about Tyrannosaurus rex , arguably Earth’s most famous dinosaur . After reviewing decades of mounting evidence, researchers documented around 150 morphological differences across multiple supposed juvenile T. rex skeletons. Instead of young dinosaurs, these were actually adult examples of an entirely separate species now known as Nanotyrannus lancensis .

While Nanotyrannus was dwarfed by its massive relative, it still reached an impressive 18 feet long and weighed as much as 1,500 pounds.…