Weevils of the Yixian Formation, China (Coleoptera: Curculionoidea): phylogenetic considerations and comparison with other Mesozoic faunas

The weevil fauna of the Yixian Formation, north-eastern China, is described and compared with other deposits of similar age and older. The fauna contains fossil groups that appear to be basal curculionoids, representing a mixture of taxa belonging to extant lineages and possibly extinct stem-groups. It contrasts particularly with Mesozoic curculionoids described from the Karatau site in southern Kazakhstan and El Montsec, Spain, the Yixian being quite different from the former due to its younger age. Although diagnoses are provided and characters are discussed, much of the taxonomy is considered tentative pending a full cladistic analysis and outline of diagnostic, synapomorphic characters. Most prior accounts have suffered from a reliance on the literature, which is grossly erroneous in many cases, rather than direct examination of fossil type material, and this has led to biased interpretations. Taxonomic changes made are: Leptocar Liu & Ren, 2007 is considered to be a junior synonym of Cretonanophyes Zherikhin, 1977; Cretonanophyes punctatus Liu & Ren, 2007, and Cretonanophyes zherikhini Liu & Ren, 2006 are resurrected as combinations; Leptocar polychaetus Liu & Ren, 2007 is regarded as a junior synonym of C. zherikhini Liu & Ren, 2006; Cretonanophyes rugosithorax Gratshev & Zherikhin, 2000a is resurrected as a combination; Montsecanomalus (Rugosocar) Legalov, 2009a is considered a junior synonym of Cretonanophyes Zherikhin, 1977; Chinabrenthorrhinus Legalov, 2009a is a junior synonym of Chinocimberis Legalov, 2009b; and Chinocimberis longidigitus (Ren, 1995) is a new combination. Abrocar concavus sp. nov. and A. relicinus sp. nov. are described.