Researchers unearthed a fossilized tooth of a carnivorous dinosaur that was believed to be more than 7 meters long, the largest of its kind known to have lived in Japan.
The find, on the western coast of the Nagasaki Peninsula here, dates to 84 million years ago.
Another tooth of a smaller meat-eating dinosaur was also discovered in the same geological layer from the later Cretaceous Period (144 million years ago to 65 million years ago).
The announcement was made July 8 by the Nagasaki city board of education and the Fukui Prefectural Dinosaur Museum.
Fossils of carnivorous dinosaurs have been discovered in 12 other prefectures, including Fukui and Fukuoka.
Researchers said the two teeth fragments, one of which is half of the root portion, are in poor condition, making it difficult to identify the type of dinosaurs.
The fragment is 3.5 centimeters high, 2.7 cm wide and 1.1 cm thick. Given these dimensions, researchers said the tooth portion above the gum was likely 6 cm high.
Compared with other finds in Japan, the carnivorous dinosaur is believed to be one of the largest animals ever to have roamed this country. The fragment also has a jagged edge, which is unique to carnivorous dinosaurs.
The other fragment is a part of a tooth portion above the gum. It is 3.4 cm high and 1.4 cm wide.
The Nagasaki city board of education and the Fukui Prefectural Dinosaur Museum have been jointly studying the fragments since fiscal 2012.