Open AccessA TOOTH OF THE EXTINCT LAMNID SHARK, COSMOPOLITODUS PLANUS COMB. NOV. (CHONDRICHTHYES: ELASMOBRANCHII) FROM THE MIOCENE OF POHANG CITY, SOUTH KOREA
Author(s) -
Changyu Yun
Publication year - 2021
Publication title -
acta palaeontologica romaniae
Language(s) - English
Resource type - Journals
eISSN - 2248-3802
pISSN - 1842-371X
DOI - 10.35463/j.apr.2022.01.02
Subject(s) - elasmobranchii , chondrichthyes , genus , peninsula , pelagic zone , paleontology , biology , taxon , geology , zoology , ecology
An isolated, upper lateral tooth of the extinct lamnid shark Cosmopolitodus planus (Agassiz, 1856), is described from middle Miocene marine deposits (possibly the Duho Formation) in Pohang City, South Korea. This is the first confirmed record of this taxon in the Korean Peninsula. The tooth is less than half the size of a large tooth of this species, suggesting that the tooth comes either from an intermediate or posterior position within the upper jaw, or from a young individual. This report further supports the hypothesis that epipelagic or pelagic sharks were already distributed throughout the entire East Sea in the middle Miocene. It is recommended that the species planus should be transferred to the genus Cosmopolitodus based on numerous similarities with the type species of this genus, C. hastalis (Agassiz, 1838).