The ant-like stone beetle supertribe Mastigitae (Staphylinidae: Scydmaeninae) comprises nine extant and five extinct genera that exhibit unusual morphological specializations and ecological adaptions. Recent discoveries of mastigite fossils from Upper Cretaceous–middle Eocene deposits have significantly improved our knowledge of the evolutionary history of this group, yet a direct fossil record for two modern tribes of unclear affinities, i.e. Leptomastacini and Papusini, is lacking. Herein we describe a new genus and species, †Archemastax divida gen. et sp. nov., based on two well-preserved individuals entombed in mid-Cretaceous Burmese amber (c. 99 Ma), representing the earliest known representative of Leptomastacini. †Archemastax possesses both plesiomorphic and derived characters, with a few important traits shared with extant members of Papusini and Clidicini. A data set of 70 morphological characters scored for 29 species of Mastigitae was analysed using maximum parsimony and Bayesian inference; both analyses recovered a sister relationship between †Archemastax and extant leptomastacines. However, in the former analysis Leptomastacini was recovered as sister to the remaining Mastigitae, while the latter indicated an origin of Leptomastacini from within Clidicini. Although a close affinity between †Archemastax and Papusini was not supported by our analyses, similarities in some shared characters of these two groups are discussed.

http://zoobank.org/urn:lsid:zoobank.org:pub:BB17DF86-25FC-48B5-8AFB-1DB27328280F

像蚂蚁一样的甲虫超级部落玛氏斑（Staphylinidae：Scydmaeninae）包括9个现存的和5个灭绝的属，它们表现出不同寻常的形态学特征和生态适应性。最近在上白垩统-始新世沉积中发现的菱镁石化石极大地提高了我们对这一组演化历史的了解，但是缺少两个亲缘关系不明的现代部落，即Leptomastacini和Papusini的直接化石记录。在这里，我们描述了一个新的属和种† Archemastax divida gen。等。十一月，基于两个保存完好的人被埋在白垩纪中期缅甸琥珀（Ç。99马），较Leptomastacini已知最早的代表。† Archemastax既具有古朴的特征又具有派生的特征，与现存的巴布斯尼和克利迪基尼有一些重要的特征。使用最大简约度和贝叶斯推断分析了29种29科动物的70个形态特征数据集。两项分析均恢复了† Archemastax和现存的瘦素他汀之间的姐妹关系。但是，在前一种分析中，Leptomastacini是剩余的Mastigitae的姐妹，而后者则表明Leptomastacini起源于Clidicini。尽管我们的分析不支持† Archemastax和Papusini之间的紧密亲和力，但仍讨论了这两个群体在某些共有性状上的相似性。

http://zoobank.org/urn:lsid:zoobank.org:pub:BB​​17DF86-25FC-48B5-8AFB-1DB27328280F