Triceratops and Torosaurus: Same Dinosaur

Two dinosaurs became one this week, as paleontologists have just discovered that the dinosaurs previously known as Triceratops and Torosaurus are actually the same species.
(The classic image of a Triceratops is on the left, while the new face of Triceratops, previously called Torosaurus, is on the right.

For over a century, scientists thought Torosaurus was a unique species. It was characterized as having a huge frill, bigger than that of Triceratops, with two large holes in it. But Montana State University paleontologists John Scannella and Jack Horner now say the excavated Torosaurus remains were just Triceratops at different growth stages.