Revisions * new taxa * and venation transformations of the sawfly family Blasticotomidae sensu lato (Hymenoptera: ºenthredinoidea) highlight the evolution of the basal Hymenoptera Author Sun, Chenhui College of Life Sciences * Capital Normal University * Beijing 100048 * China Author Rasnitsyn, Alexandr P. Paleontological Institute * Russian Academy of Sciences * 123 * 117647 Moscow * Russia & Department of Palaeontology * Natural History Museum * Cromwell Road * London SW 7 5 BD * UK alex.rasnitsyn@gmail.com&tpgao@cnu.edu.cn Author Wedmann, Sonja Senckenberg Forschungsstation Grube Messel * Senckenberg Forschungsinstitut und Naturmuseum Frankfurt am Main * 64409 Messel * Germany Author Zhuang, Jialiang College of Life Sciences * Capital Normal University * Beijing 100048 * China Author Shih, Chungkun College of Life Sciences * Capital Normal University * Beijing 100048 * China & Department of Paleobiology * National Museum of Natural History * Smithsonian Institution * Washington * DC 20013 - 7012 * USA alex.rasnitsyn@gmail.com&tpgao@cnu.edu.cn Author Ren, Dong College of Life Sciences * Capital Normal University * Beijing 100048 * China alex.rasnitsyn@gmail.com&tpgao@cnu.edu.cn Author Gao College of Life Sciences * Capital Normal University * Beijing 100048 * China text Zoological Journal of the Linnean Society 2024 2024-09-21 202 1 1 19 http://dx.doi.org/10.1093/zoolinnean/zlae113 journal article 10.1093/zoolinnean/zlae113 0024-4082 14542355 9ECD785-00BF-494C-9888-0B0D073F302C Xyelocerus abruptus Sun, Rasnitsyn, Zhuang & Shih , sp. nov. ( Fig. 1 ) http://zoobank.org/ urn:lsid:zoobank.org:act: 4F22E9A3- FA40-459D-A8EE-A21B31CEE004 Diagnosis: Forewing with pterostigma sclerotized. Vein Sc present* forming kink to R and touching it in a point at level of 1-M base* or preserving dot-like short Sc 2 * and with Sc 1 oblique crossvein-like. 1-M bent before 1-Rs* five times as long as 1-Rs. Rs+M* 1m-cu* and 2-Cu of subequal length. Etymology: The species name is derived from the Latin word ‘abruptus’* meaning suddenly steep* referring to the kink of Sc before touching R. Material: Holotype * CNU-HYM-NN2022311 . Paratypes : CNU-HYM-NN2022312 ; CNU-HYM-NN2022313 ; CNU-HYM-NN2022314 ; CNU-HYM-NN2022315 (poorly preserved* sex unknown); CNU-HYM-NN2022316 (poorly preserved* sex unknown) . Locality and horizon: Latest Middle Jurassic (late Callovian)* Jiulongshan Formation; Daohugou Village * Wuhua Township* Ningcheng County * Chifeng City * Inner Mongolia * China . Description ( Fig. 1A–C ): Holotype * CNU-HYM-NN2022311 . Very incompletely preserved. Sex unknown. Body length 12.8 mm * with abdomen partly preserved. Head: Temples convex* extending lateral beyond eyes. Antenna incompletely preserved. Forewing: Left forewing length 11.4 mm as preserved. Pterostigma fully sclerotized. Sc forming kink and touching R in a point at level of 1-M base; Sc 1 oblique ( Fig. 1C ). Two adventitious ‘1-Rs’ present before true one in left forewing* forming two small cells. 1-M ( 1.88 mm ) straight and ~6.2 times as long as 1-Rs ( 0.30 mm ). Vein M+Cu slightly bent. Crossvein 1r-rs shorter than 2-RS. Cell 1r small* 1mcu large* Rs+M* 1m-cu and 2-Cu of subequal length. Legs: Left hind tibia narrow* 5.3 mm long. Paratype CNU-HYM-NN2022312 ( Fig.1D, E ) Sex unknown. Very incompletely preserved* preserved similar to holotype . Paratype CNU-HYM-NN2022313 ( Fig. 1F, G ) Female. Generally similar to holotype . Head and thorax dorsally coarsely punctated. Adventitious ‘1-Rs’ present before true one in right forewing ( Fig. 1G )* forming a small cell. Body length 19.9 mm * right forewing length 15.6 mm * ovipositor length 3.4 mm . Paratype CNU-HYM-NN2022314 p/c (part and counterpart) ( Fig.1H, I ) Sex unknown. Body and wings very incompletely preserved. As preserved* similar to holotype . Adventitious ‘1-Rs’ present before true one in right forewing ( Fig. 1I )* forming a small cell. Right forewing length 14.8 mm as preserved.