A fossil assumed to be a toe bone of a dinosaur dating back to 120 million years ago has been discovered on a western island, a local government said Wednesday.

The city government of Ansan, southwest of Seoul, said the 4.5-centimeter-long fossil was found by a citizen on Daebu Island last month.

It is believed to have belonged to a plant-eating basal ceratopsian dinosaur known as Koreaceratops, which existed on the Korean Peninsula about 120 million years ago during the Albian age.

The phalanx fossil was almost perfectly preserved, officials said.

The city government reported the finding to the Cultural Heritage Administration (CHA).

The CHA views the remains as having academic value and plans to send it to the National Research Institute of Cultural Heritage for a more detailed study.

In 2000, five dinosaur footprints, likely left about 100 million years ago, were found at a quarry on the island. (Yonhap)