Rhyzobius Stephens, 1829 is a diverse genus of ladybird beetles (Coccinellidae) with more than 100 extant species distributed in the Old World. Despite recent revision of that genus its internal classification has been unclear. However, based on morphological differences, four main evolutionary lineages could be expected, two distributed in Euro-African and two in the Australo-Oriental regions. The oldest representatives of Rhyzobius were described quite recently from early Eocene amber deposited in Oise, France. Three more species belonging to this genus were found in Baltic amber and are described here as R. groehni sp. nov., R. sontagae sp. nov. and R. szwedo sp. nov. In order to test the systematic placement of extinct taxa, a phylogenetic analysis was conducted, combining extant and extinct species of Rhyzobius. A dataset of 74 morphological characters scored for 29 recent and four extinct species across the genus Rhyzobius was analysed using maximum parsimony and Bayesian inference methods. This is the first morphology-based phylogeny of the genus Rhyzobius supporting the existence of four evolutionary lineages of modern taxa. All extinct taxa, from both the Oise and Baltic ambers, form a distinct group in the single clade within the African group of species. Based on the results of the phylogenetic analysis, a discussion on the historical biogeography of the genus is provided.

https://zoobank.org:pub:7CAE0F5B-F03E-4E07-A59D-7985AB7B452F

Rhyzobius Stephens，1829年，是瓢虫（Coccinellidae）的一个不同属，在旧大陆分布着100多种现存物种。尽管最近对该属进行了修订，但其内部分类尚不清楚。但是，基于形态差异，可以预期有四个主要的进化谱系，两个分布在欧洲-非洲和两个分布在东澳大利亚地区。Rhyzobius的最古老的代表来自法国瓦兹省的始新世早期琥珀。在波罗的海琥珀中还发现了该属的另外三个物种，这里被称为R. groehni sp。十一月，R. sontagae sp。十一月 和R.szwedosp。十一月 为了测试灭绝类群的系统放置，结合了现存和灭绝的根瘤菌种进行了系统发育分析。使用最大简约和贝叶斯推断方法分析了根瘤菌属中最近29种和四个已灭绝物种的74个形态特征数据集。这是Rhyzobius属的第一个基于形态学的系统发育，支持现代分类单元的四个进化谱系的存在。来自瓦兹和波罗的海琥珀的所有灭绝的分类单元在非洲物种组的单个进化枝中形成一个独特的组。根据系统发育分析的结果，对属的历史生物地理学进行了讨论。

https://zoobank.org:pub:7CAE0F5B-F03E-4E07-A59D-7985AB7B452F