Glirid dental material is described from the Middle Miocene channel fill of the Hambach open-cast lignite mine in northwestern Germany. The fauna Hambach 6C shows a high diversity with seven species in six genera: Glirudinus undosus, Muscardinus thaleri, Muscardinus sansaniensis, Miodyromys aegercii, Paraglirulus werenfelsi, Microdyromys koenigswaldi, and Paraglis astaracensis, which are characteristic taxa in Middle Miocene European localities. Regarding the faunal composition and high diversity, the Hambach 6C assemblage is closest to that of the MN 5 locality Schönenberg in southern Germany, but also shares many taxa with late Middle Miocene faunas. The species richness of glirids, combined with other vertebrate remains in Hambach 6C indicates a warm, humid forested environment during the Mid-Miocene Climate Optimum (MCO).
We are very thankful to the mining company RWE POWER AG (Cologne) for the continuous support during fieldwork in the Hambach mine. ZY.L. received support from the National Natural Science Foundation of China (NSFC 42172010) and Chinese Government Scholarship (CSC 202106970018). T.M. was funded by the Deutsche Forschungsgemeinschaft (DFG) Special Research Project SFB 350.