Calosoma kimi Lee & Nam, 2021

Lee, Soo Bin & Nam, Gi-Soo, 2021, A new species of fossil Calosoma (Coleoptera: Carabidae) from the Geumgwangdong Formation (Early Miocene), South Korea, Zootaxa 5072 (1), pp. 1-11 : 3-5

Species Calosoma kimi Lee & Nam, 2021 sp. nov.

Material. Holotype GNUE-311001, Paratype GNUE-311002 .

Locality. Geumgwangri, Donghaemyeon, Namgu, Pohangsi, Gyeongsangbukdo, South Korea.

Geological Age. Early Miocene

Etymology. Honoring Professor Jong Heon Kim for his important work on fossils from Pohang, South Korea.

Diagnosis. The 5 th interval connected to the 7 th interval and the 6 th interval surrounded at the apex of elytron; the 11 th and 13 th intervals connected and surround the 12 th interval; the 10 th and 14 th intervals connected and surrounded the 11 th and 13 th; the 16 th to 18 th intervals smaller. Scales on the 13 th to 16 th interval small and deeply grooved, forming checkered patterns from the base to the middle part of the elytron and forming overlapping patterns from the middle part to the apex of the elytron.

Description. GNUE-311001 is sedimented in shaly mudstone with a damaged leaf ( Fagus ?) ( Fig. 2 ). The head, half of the thorax, both damaged elytra, and parts of profemur and protibia and right mesotarsus are preserved. The total length of the specimen from the tip of the head to the apex of the elytra is 30.7 mm, and the width from the margin of the elytron to the outer margin of the pronotum is 12.4 mm ( Fig. 3a and b ). The shape of the fossil is flat, probably because of sedimentation. GNUE-311002 is in mold form. It was sedimented in the shale, only preserved with the right elytron ( Fig. 4a and b . The length of the GNUE-311002 is 23 mm, and the width is 6 mm.

Head: Head is well preserved with loss of left maxillary palp and several antennae segments on the GNUE-311001. The left 1 st and 3 rd antennomeres and the right 2 nd and 3 rd antennomeres are preserved. The right maxillary palp is well preserved. The length of the last and 2 nd maxillary palpomeres is approximately 1 mm. Both dentaries are poorly preserved, but it seems that the dentaries are protruded. The right 1 st and 2 nd labial palpomeres are preserved. Compound eyes are not preserved, but a trace of the compound eyes is poorly preserved on the middle part of the head. The shape of the head is triangular. The length of the head is 3 mm, and the width is 4.7 mm.

Thorax: On the GNUE-311001, only a part of the right pronotum is preserved. The side of the pronotum is rounded and bordered in shape, which is a diagnostic feature of Calosoma ( Hashmi et al. 2005) . The shape of the pronotum is rounded but slightly angled at the middle part of the lateral margin. The length of the pronotum is 5 mm. The width of the right pronotum is 4 mm. Although the pronotum is not completely preserved, on the basis of the width of the right pronotum, we assume the full width of the pronotum is 8 mm.

Elytron: On the GNUE-311001, both elytra are partly preserved. One big hole is grooved on the left elytron and from the middle to the apex of the medial part of the left elytron, and the outline of the left elytron is also partly not preserved. On the right elytron, only a part of the wing base is preserved. GNUE-311002 consists of partly preserved elytron ( Fig. 4 ). The shape of the elytron is quadrangle-like. The medial outlet line is thin. The total countable striae are 19 and intervals are 18. The 1st interval is small. The 4 th to 8 th intervals are large and become smaller from the 9 th interval. The 16 th to 18 th intervals are smallest and fainter than other intervals. Transversal lines are clearly showing from the 5 th to 16 th intervals. Grooved dimples are shown on the 4 th, 8 th, and 12 th intervals, creating a triploid pattern ( Jeannel 1940). The 5 th and 7 th intervals are connected at the apex of the elytron and surround by the 6 th interval. The 11 th and 13 th intervals are connected at the near margin of the elytron and surround the 12 th interval. The 10 th and 14 th intervals meet and surround the 11 th to 13 th intervals at the apex of the elytron. These interval connection patterns are clearly visible on GNUE-311002 ( Fig. 5 ).

The scales are deeply grooved from the 9 th to 15 th interval. The scales on the 17 th and 18 th intervals are extremely small. From the wing base to the middle of the elytron, the scales are arranged in a check pattern. However, from the middle to the margin of the elytron, the scales are arranged in an overlapping pattern ( Fig. 6 ).

Leg: On GNUE-311001, part of the left profemur and protibia segments and the right leg tarsus (assumed mesotarsus) are preserved. The tarsus on the right leg is forward to the upside. We assume that it is broken and folded upward.

Figures

FIGURE 2. Photograph of specimens. (a). GNUE-311001. (b). GNUE-311002.

FIGURE 3. Calosoma kimi sp. nov. holotype (GNUE-311001). (a). Photograph of the specimen. (b). Sketch of the specimen.

FIGURE 4. Calosoma kimi sp. nov. paratype (GNUE-311002). (a). Photograph of the specimen. (b). Sketch of the specimen.

FIGURE 5. The apex of the wing of C.kimi sp. nov. paratype (GNUE-311002). (a). Photograph of the 10th to 14th interval connection patterns. (b). Sketch of the 10th to 14th interval connection patterns. (c). Photograph of the 5th to 7th interval connection patterns. (d). Sketch of the 5th to 7th interval connection patterns.

FIGURE 6. Scales on elytron of C. kimi sp. nov. Scales on the above represents a checkered patterns. Scales on the bottom represents an overlapping patterns.