sciencehabit writes In, the U.S. Postal Service issued colorful dinosaur stamps, including one for Brontosaurus. Paleontologists and educators loudly protested that the correct scientific name for the iconic beast was Apatosaurus—a fact that even lay dino aficionados and many 8-year-olds took pride in knowing. But now, a dinosaur-sized study of the family tree of the Diplodocidae, the group that includes such monstrous beasts as Apatosaurus, Diplodocus, and Barosaurus, finds that USPS got it right: The fossils originally called Brontosaurus show enough skeletal differences from other specimens of Apatosaurus that they rightfully belong to a different genus. The study, published online this week in the journal PeerJ, brings the long-banished name back into scientific respectability as a genus coequal with Apatosaurus.