Image caption, No youngster: the researchers reject Triceratops, with its shorter frill, is merely a young Torosaurus "It has a small hole in its frill whereTorosaurushas a larger hole ...

Until now the Triceratops and the lesser-known Torosaurus were the thought to be the same type of dinosaur. The Torosaurus with its big horns was meant to be grown up and the Triceratops was meant ...