A new stag beetle fossil is described from the Yixian Formation in northeastern China. A new genus is established based on this well-preserved specimen. Prolucanus beipiaoensis gen. et sp. nov. is firmly placed in the extant lucanid subfamily Lucaninae based on its broad prosternal process and geniculate antennae. Our discovery represents the first fossil record of Lucaninae from the Late Mesozoic of China and the oldest reliable record belonging to the subfamily. We also summarize the fossil species of stag beetles found in China and the described fossil species of the subfamily Lucaninae found in the world. A key to all fossil genera of Lucanidae from China is provided.

In this paper, the subgenus Thailandia Bílý, 1990 of the genus Anthaxia Eschscholtz, 1829 from China is reported, including two species: A. (T.) svatoplukbilyi Qi & Song, sp. nov. from Guangxi and A. (T.) rondoni Baudon, 1962 from Yunnan. The description and illustrations of the new species are provided, the illustrations and information of A. (T.) rondoni from Yunnan are given for the first time, and the diagnostic characters are provided to distinguish the new species from other related species.

In the present study, a new stag beetle, namely Prosopocoilus wangae Qi, Bian & Xin, sp. nov., from Vietnam is described and illustrated. This new species has long been misidentified as the Vietnamese population of P. mysticus mysticus Parry, 1870, but it can be clearly distinguished from the latter by its external details and genital characters. Moreover, an updated checklist of Vietnamese taxa of Prosopocoilus Hope, 1845 is provided.

In this paper, we describe a new stag beetle species from Yunnan, China, i.e., Neolucanus horizontalis Xin, Zhong & Qi, new species which exhibits significant structural differences in mandible, labial vestiture, protibia and male genitalia compared to related species. We also provide redescription of the male of N. fuscus Didier, 1926 and N. brochieri Bomans & Miyashita, 1997. Neolucans fuscus zhongguo Schenk, 2012 is synonymized with N. fuscus fuscus Didier, 1926. We also present a distribution map and an identification key for the telodont males of the N. fuscus group. Finally, we discuss the species group affiliation of N. baongocae Nguyen, 2013.

A new stag beetle is described from Yunnan Province, China: Lucanus jiaozishanus Qi, He, Su & Song, new species. It is the third species of the L. boileaui group which are distributed only in Southwestern China and Northeastern Myanmar. The differences of the new species with the more related taxa (L. boileaui Planet, 1897, L. ludivinae Boucher, 1998 and L. takeoi Adachi, 2020) are discussed. A new synonymy, L. bidentis Schenk, 2013 = L. boileaui, is proposed. Keys to males and females of the L. boileaui group are provided. The variation of males, the female and the host plant of L. takeoi (L. maculifemoratus group) are illustrated for the first time.

A new fossil stag beetle genus, Cretofigulus gen. nov., is identified and described from mid-Cretaceous Kachin amber from northern Myanmar. Two new species, C. caoqiangi sp. nov. and C. hollowayae sp. nov. are herein described and illustrated. Additionally, the morphological differences between Cretofigulus gen. nov. and the related extant genus Figulus Macleay, 1819 are discussed. Cretofigulus gen. nov. is the second fossil record of the subfamily Lucaninae from Burmese amber. Despite an evolutionary divergence of approximately 99 million years, Cretofigulus gen. nov. exhibits a striking morphological resemblance to extant Figulus. Key diagnostic features of Cretofigulus gen. nov., including reduced sexual dimorphism, suggest behavioral and ecological parallels with modern Figulini Burmeister, 1847, such as carnivorous feeding habits and adaptation to a monogamous lifestyle within decaying wood.