The dinosaur with 1000 teeth is a common misconception. There is no dinosaur with 1000 teeth. However, the dinosaur with the most teeth is Nigersaurus taqueti, which had more than 500 teeth aligned like piano keys on the front of its vacuum cleaner-style jaw. The teeth were arranged in dental batteries, which erupted in unison, not each column individually. The enamel on the teeth of Nigersaurus was highly asymmetrical, ten times thicker on the outwards facing side than on the inner side. Each tooth was replaced once every 14 days, and the tooth replacement rate was the highest of any known dinosaur. The dinosaur had a delicate skull and an extremely wide mouth lined with teeth especially adapted for browsing plants close to the ground. The Nigersaurus was about 30 feet long and lived during the most ancient Cretaceous period, between 145 million to 100 million years ago.