Antarctotrechusballi sp. n. (Carabidae, Trechini): the first ground beetle from Antarctica Author Ashworth, Allan C Author Erwin, Terry L. text ZooKeys 2016 635 109 122 http://dx.doi.org/10.3897/zookeys.635.10535 journal article http://dx.doi.org/10.3897/zookeys.635.10535 1313-2970-635-109 9B1AF440DC5B413796461ED8B28140F0 9B1AF440DC5B413796461ED8B28140F0 Antarctotrechus balli Ashworth & Erwin sp. n. Holotype (sex unknown), a right elytron. Antarctica, Oliver Bluffs, Beardmore Glacier region, Meyer Desert Formation, 85.117222°S , 166.657500°E , (Allan Ashworth 2003) (NMNH: ADP147741). Derivation of genus name. Antarctotrechus refers to its relationship with the Trechini and the place where the specimens were found. Derivation of specific epithet. The epithet, balli , is a Latinized eponym based on the family name of George E. Ball, Carabidologist, and academic leader of a host of younger carabidologists, in celebration of his 90th birthday, September 26, 2016. Proposed english vernacular name. Ball's Antarctic Tundra Beetle. Diagnosis. Only the left and right elytra known (Figure 5). They are from two individuals. Form as in alate Neaustral trechines in the genus Trechisibus Motschulsky 1862. Lack of recurrent groove as in Andean and Pampas trechines in the genera Oxytrechus Jeannel 1927 and Pseudocnides Jeannel 1927 , respectively. Placement of mid-discal elytral setiferous pore as in Trechisibus and other trechines, Placement of preapical in third interneur unique (Figures 6-7). Absence of apical elytral setiferous pore in third interneur unique. Figure 5. Fossils of the left and right elytra of Antarctotrechus balli sp. n. A The left elytron, 2.36 mm in length, is designated as the paratype (USNM: ADP147732). A small part of the right elytron of the same individual is attached along the suture near the apex. The siltstone matrix is visible along the outer margin near the apex. The small rhomb-shaped crystals on the surface are authigenic calcite B The right elytron is designated as the holotype. (NMNH: ADP147741). The elytron is 2.40 mm in length. The base is deformed by a crack and concealed by sediment grains. A small part of the left elytron of the same individual is still attached along the suture near the base. Figure 6. Fossil of right elytron of Antarctotrechus balli sp. n. and elytra of three species of Neaustral Trechisibus spp. with line drawings of each showing 3rd interval setigerous pores and recurrent grooves of the latter. Figure 7. Comparison of the apices of the fossil right elytron Antarctotrechus balli sp. n. and a modern Trechisibus sp. with line drawings of each showing 3rd interval setigerous pores and recurrent grooves of the latter. An isodiametric microornament is partially visible on the fossil. Description. (Figures 5-7). Size: Elytron length and width within range of Trechisibus species, Length 2.36 mm, W = 0.85 mm. Color: Typically trechine brown. Luster: Unknown due to deposition and lithification processes over ~ 20 -14 Ma. Microsculpture: Apparently isodiametric. Head: Unknown. Prothorax: Unknown. Pterothorax : Shape of humerus (compare Figure 5) not sloped, indicating the adult was possibly fully winged. Legs: Unknown. Abdomen: Unknown. Male genitalia: Unknown. Female genitalia: Unknown. Dispersal potential. If these beetles were macropterous (see above), they were likely capable of flight. Trechisibus adults are moderately swift and agile runners, so likely were adults of Antarctotrechus balli . All known species of Tasmanorites are brachypterous. Other specimens examined. A left elytron also from the type locality is designated as the paratype. This specimen is reposited in the collections of the Smithsonian Institution National Museum of Natural History (NMNH:ADP147732).