Mama Duck, the world’s largest rubber duck, has invaded the Emerald City. Mama Duck made her way into town on Jan. 31 for the Seattle Boat Show, with her stay expected to last through Feb. 8.

This massive footprint is believed to belong to a giant Saurolophus, a duck-billed dinosaur estimated to exceed 15 meters in length. This would make it larger than even famous predators like ...