Size and Weight:
It's not often that dinosaurs are dug up in the southeastern U.S., so the discovery in 2005 of Appalachiosaurus was big news. The fossil, believed to be of a juvenile, measured about 23 feet long, and the dinosaur that left it probably weighed a bit less than a ton. Abstracting from other tyrannosaurs, paleontologists believe a full-grown adult might have measured about 25 feet long and weighed about two tons.
Weirdly, Appalachiosaurus shares a distinctive feature--a series of ridges on its snout--with an Asian tyrannosaur, Alioramus. However, experts believe Appalachiosaurus is most closely related to another North American predator, the even larger Albertosaurus. (By the way, the specimen of Appalachiosaurus, as well as one of Albertosaurus, show evidence of Deinosuchus bite marks--indicating that this Cretaceous crocodile occasionally tried to take down big dinosaurs!)