New insights into the phylogeny of Stephanidae (Hymenoptera: Apocrita), with a revision of the fossil species Author Ge, Si-Xun https://orcid.org/0000-0003-3769-1530 College of Forestry, Beijing Forestry University, Beijing 100083, China Author Jiang, Zhuo-Heng School of Science, Westlake University, Hangzhou, China Author Ren, Li-Li College of Forestry, Beijing Forestry University, Beijing 100083, China lily_ren@bjfu.edu.cn Author van Achterberg, Cornelis https://orcid.org/0000-0002-6495-4853 Shaanxi Key Laboratory for Animal Conservation / Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, 229 North Taibai Road, Xi' an, Shaanxi 710069, China kees@vanachterberg.org Author Tan, Jiang-Li Shaanxi Key Laboratory for Animal Conservation / Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, 229 North Taibai Road, Xi' an, Shaanxi 710069, China tanjiangli@sina.com text Arthropod Systematics & amp; Phylogeny 2023 2023-11-02 81 819 844 http://dx.doi.org/10.3897/asp.81.e107579 journal article http://dx.doi.org/10.3897/asp.81.e107579 1864-8312-81-819 50EE94AAD90A43E1B54E4FADE22F4668 70148F72D847500A930DA76D2196759A † Denaeostephanus chaofeng sp. nov. Figures 14 , 15 Holotype. ♀; BFU, Baltic amber, Eocene. Part of Si-Xun Ge's collection Etymology. The new species was named after the third son of the Loong in Chinese mythology as the third species of † Denaeostephanus . Diagnosis. Pronotum comparatively robust, neck without distinct pronotal fold; anterior, middle and posterior part of pronotum almost at the same level in lateral view; mesonotum at the same level of pronotum; forewing with vein 1-M arched; vein 2Rs+M extremely short; vein 2Cua and 2Cub nebulous; hind femur relatively slender (Fig. 15D ), minor teeth between basal and distal large tooth rather weakly developed; tergum I and sternum I fused (Fig. 14C ; Fig. 15C ), tergite I elongated as about 0.5 x as long as remainder of metasoma. Figure 14. Denaeostephanus chaofeng Ge and Tan, sp. nov. Holotype ♀. A Photo of specimen. B Line drawing of habitus. C Metasoma, lateral view. D Hind leg. Figure 15. Details of Denaeostephanus chaofeng Ge and Tan, sp. nov. Holotype ♀. A Head, frontal-oblique view. B Wings. C Metasoma. D Hind leg. Description. Description: Female. Total body length (without ovipositor sheath) 3.6 mm; forewing length ca. 2.4 mm; ovipositor sheath 2.9 mm. - Head : Antenna with 19 flagellomeres; the first flagellomere short and robust while the second is elongated and slender; Head sub-globular (probably more or less traverse in dorsal view), with compound eyes occupying most part of lateral surface; vertex with five acute and triangular tubercles; temple comparatively flat, coriaceous; occipital carina distinctly developed and connected to hypostomal flange; hypostomal flange strong, without distinct rugae. Maxillary palpus 5-segmented, elbowed between MP II (maxillary palpomere II) and MP III; MP I and MP II distinctly short and strong, MP III-V long and slender; MP III slightly less than twice length of MP IV and MP V. - Mesosoma : Pronotum robust; neck without distinct pronotal fold; neck at almost same level of middle part of pronotum postero-dorsally; middle and posterior part of pronotum coriaceous, with slightly transverse carinae; middle part of pronotum not distinctly differentiated from posterior part; mesonotum at the same level of pronotum, without setosity; propleuron and mesopleuron coriaceous or imbricate; propodeum with its lateral view micro-sculptured; scutellum invisible. - Wings : Forewing with vein 1-M distinctly curved, 2.9 x as long as vein 1-Rs and 1.7 x vein 1m-cu; vein 2-Rs long, ca. 3.8 x as long as vein r-rs; vein r-rs ends inner side of pterostigma behind the level of apex of pterostigma; parastigmal vein (pv) ca 0.4 x as long as pterostigma; vein 2Rs+M (= Rs+Mb) extremely short, with its apical slightly incision at the origin of veins 2-Rs and apical abscissa of vein M; vein 2Cua and 2Cub nebulous. - Legs : Hind coxa comparatively slender, coriaceous, spindle shaped without transversely striate; hind femur coriaceous, relatively slender; ventral surface of hind femur bidentate, with its widest tooth developed at near 0.35 x as its basal part; a more acute triangular tooth developed near 0.3 x as its distal part with two small teeth behind, only one minor tooth weakly developed behind the basal large tooth; hind tibia about 1.2 x as long as hind femur, with its basal narrow part as equal length as apical widened part, inner side of widened part basally moderately depressed; hind tarsus with five tarsomeres; basitarsus rather elongate, slightly longer than the length of all other tarsomeres. - Metasoma : Tergite I elongated and about 0.5 x as long as the remainder of metasoma; tergite I with its ventral length 3.0 x its maximum width; pygidial area not protruding apically; ovipositor sheath ca 0.8 x as long as total body length and 1.2 x as long as forewing length. Ovipositor tip laterally compressed, without distinct teeth apically. Remarks. Two † Denaeostephanus species, † D. sulcatus (Aguiar and Jazen, 1999) and † D. tridentatus (Brues, 1933), have been recognized before and only males have been described. This is also the first discovery of a female belonging to the genus, and thus we could supplement key characteristics of † Denaeostephanus in phylogenetic research, such as the 5-segmented hind tarsus. Obviously, the single voucher specimen corrected the speculation of the 3-segmented hind tarsus by van Achterberg (2002) . According to our phylogenetic analysis, † Denaeostephanus belongs to the subfamily Stephaninae and is a sister to all extant genera of the subfamily.