FIRST CALOSOMA FOSSIL FROM THE KOREAN PENINSULA AND A REVIEW OF THE FOSSIL RECORD OF THE GENUS CALOSOMA

The genus Calosoma is a member of the family Carabidae. In all, 128 extant species have been reported (Bruschi, 2013). Fossils of the genus Calosoma have been discovered from Europe, North America, and Asia, from the ages of Eocene to Quaternary. Most fossil Calosoma species were discovered from the Miocene age with 15 species. The poorest record of Calosoma fossils is of Oligocene age with only 3 species.

Here, I present the first fossil Calosoma from the Korean peninsula and a review of the fossil record of the genus Calosoma. A Calosoma fossil species from the Korean peninsula was discovered from the Geumgwangdong formation where the paleoenvironment is considered as lacustrine. The age of the formation is estimated as early Miocene. In comparison to other Miocene Calosoma, the Calosoma from the Geumgwangdong formation contains a diagnostic characteristics such as the pattern on of the interval connection connections which is a line lines between striae on the elytron, and 2 types of scales on the elytron. Therefore, it was considered as a new species and named Calosoma kimi by Lee and Nam (2021). Based on morphological features, C. kimi seems to contain characteristics similar to those of the subgenera Australodrepa, Calodrepa, and Calosoma. More systematical research would be required.

A reclassification of several fossil Calosoma might be required. For example, Fujiyama (1987) described a C. sp which he hypothesized might be similar to the subgenus Callitropa. The author did not describe the pattern of the connection of striae or intervals which were used for classification of the fossil Calosoma from Germany by Heer (1860) and Lee and Nam (2021). It can probably a method for classification of the C. sp by Fujiyama (1987). Zhang (1989) described 11 specimens of C. cf. maderae from Shawang formation. Jeannel (1940) described characteristics of C. maderae as showing a tendency of splitting on tertiary intervals, but this was not described for C. cf. maderae. Also, molecular results from Toussaint and Gillett (2018) showed that C. maderae was split from C. auropunctatum in the Pliocene age. This is much later than the Shanwang formation where C. cf. maderae was discovered. Therefore, specimens described as C. cf. maderae by Zhang (1989) probably require reclassification.