An extraordinarily preserved new genus and species of Trachypachidae (Coleoptera, Adephaga) from the Early Jurassic of Germany and a review of fossil trachypachid genera.

Liassodites obsti gen. et sp. nov., an Early Jurassic member of Trachypachidae, is described from Western Pomerania (Germany). An epoxy resin transfer method is applied for the preparation of three-dimensionally preserved fossil. An annotated list of Palaeozoic and Mesozoic trachypachid genera was elaborated. For each trachypachid fossil member and erroneously placed genus, a short diagnosis or available arguments on systematic position are proposed. The relations of the subfamilies Eodromeinae and Coptoclaviscinae (Coptoclavidae) are discussed. The description of Liassodites obsti gen. et sp. nov. makes it possible to suppose that the currently recognised hiatus between families Carabidae and Trachypachidae is not great enough to regard them as two separate families. The genus Coptoclavisca should be regarded as a member of Trachypachidae or Carabidae (including Trachypachinae). The new genus Apermunda gen. nov. is proposed for Petrodromeus minor. Novunda nom. nov. is proposed for Unda and the following binominal names are changed: Novunda angulata comb. nov., N. cursoria comb. nov., N. microplata comb. nov., N. pachycephala comb. nov. and N. chifengensis comb. nov. A synonymy of Evertus and Fortiseode is established, with change of species name: Evertus pervalimand comb. nov. The taxa Beipiaocarabus, Leptopodocoleus (including Leptopodocoleidae), Praedodromeus, Procalosoma, Xinbinia, 'Eodromeus' viriosus, 'Unda' chonggezhuangensis and 'Unda' pandurata, 'Karadromeus' xiangfanggouensis are regarded as incertae sedis. [ABSTRACT FROM AUTHOR]