New Example of Cosmopolitodus hastalis (Lamniformes, Lamnidae) from the Miocene of South Korea

Abstract

The author reports the discovery of an isolated juvenile tooth of an extinct lamnid shark Carcharodon hastalis from the Duho Formation, Pohang City, South Korea. This tooth is approximately 11 mm in height, suggesting a juvenile affinity of an individual this tooth originated. In life, the shark is estimated to have been approximately less than 2 m in length. This is the second reported fossil record of Carcharodon hastalis in the Korean Peninsula and the first permineralized fossil remain as well. Although largely undescribed, fossil shark assemblage of the Duho Formation is similar to those of contemporaneous Japanese marine sediments, indicating epipelagic or pelagic sharks were already diversified throughout the East sea during the Middle Miocene.