Early evolution of Anamorphidae (Coleoptera: Coccinelloidea): the oldest known anamorphid beetles from Upper Cretaceous amber of northern Myanmar and the first report of potential glandular pores in the family.

In order to place newly discovered fossil taxa (Palaeosymbius gen. nov. with P. groehni and P. mesozoicus spp. nov.) from the mid-Cretaceous amber from northern Myanmar, we investigated the relations of extant and extinct lineages of the coccinellid group of Coccinelloidea with emphasis on the family Anamorphidae. We assembled a taxonomic sampling of 34 taxa, including 15 genera and 19 species of Anamorphidae, the most comprehensive sampling of Anamorphidae at the generic level in a phylogenetic analysis. A morphological dataset of 47 characters was built as well as a molecular alignment of 7140 bp including fragments of eight genes (12S, 16S, 18S, 28S, COI, COII, H3 and CAD). Five anamorphid and one endomychid species were sequenced for the first time and added to the dataset. We performed parsimony-based analysis of the morphological dataset and Bayesian inference analysis of the combined matrix (morphological plus molecular data). Our results confirm that Palaeosymbius belongs to Anamorphidae and represents the oldest known member of this family so far. Among Anamorphidae, Symbiotes (with extant and known Eocene species) was recovered as the most probable closest relative of Palaeosymbius. Our morphological studies additionally revealed the presence of probable glandular openings in the anterolateral corners of the pronotal margins in Asymbius sp. and Anamorphus sp., representing the first report of secretory openings in the family Anamorphidae. Similar openings are found in other cucujiform beetles such as Cryptophagidae and Boganiidae with possible defensive purposes.

Museomics unveil systematics, diversity and evolution of Australian cycad-pollinating weevils.

Weevils have been shown to play significant roles in the obligate pollination of Australian cycads. In this study, we apply museomics to produce a first molecular phylogeny estimate of the Australian cycad weevils, allowing an assessment of their monophyly, placement and relationships. Divergence dating suggests that the Australian cycad weevils originated from the Late Oligocene to the Middle Miocene and that the main radiation of the cycad-pollinating groups occurred from the Middle to the Late Miocene, which is congruent with the diversification of the Australian cycads, thus refuting any notion of an ancient ciophilous system in Australia. Taxonomic studies reveal the existence of 19 Australian cycad weevil species and that their associations with their hosts are mostly non-species-specific. Co-speciation analysis shows no extensive co-speciation events having occurred in the ciophilous system of Australian cycads. The distribution pattern suggests that geographical factors, rather than diversifying coevolution, constitute the overriding process shaping the Australian cycad weevil diversity. The synchronous radiation of cycads and weevil pollinators is suggested to be a result of the post-Oligocene diversification common in Australian organisms.

Phylogeny and evolution of Mesozoic and extant lineages of Histeridae (Coleoptera), with discovery of a new subfamily Antigracilinae from the Lower Cretaceous.

In order to place a newly discovered species Antigracilus costatus gen. sp. n. from the Lower Cretaceous Yixian Formation (China) and to assess previously unplaced fossil taxa, we investigated the relationships of extant and extinct lineages of Histeridae based on three data sets: (i) 69 morphological characters belonging to 48 taxa (representing all 11 subfamilies and 15 of 17 tribes of modern Histeridae); (ii) partitioned alignment of 6030 bp from downloaded nucleotide sequences (28S, CAD, COI, 18S) of 50 taxa (representing 10 subfamilies and 15 of 17 tribes of modern Histeridae); and (iii) a combined morphological and molecular dataset for 75 taxa. Phylogenetic analyses of the morphology and combined matrices recovered the new Lower Cretaceous taxon as a sister group to remaining Histeridae and it is placed in †Antigracilinae subfam. n. †Antigracilinae constitutes the earliest record of Histeridae from the Lower Cretaceous Yixian Formation (∼125 Myr), backdating the minimum age of the family by 25 Myr from the earliest Cenomanian (~99 Myr) to the Barremian of the Cretaceous Period. Our molecular phylogeny supports Histeridae to be divided into seven different clades, with currently recognised subfamilies Abraeinae (sensu lato), Saprininae, Chlamydopsinae, and Histerinae (sensu lato) recovered as monophyletic, while Dendrophilinae, Onthophilinae, and Tribalinae are polyphyletic taxa. The Burmese amber species †Pantostictus burmanicus Poinar & Brown is placed as a sister group to the tribe Plegaderini (Abraeinae) and was assigned as a new tribe Pantostictini trib. n. Both molecular and combined phylogenies recovered the subfamilies Trypanaeinae and Trypeticinae deeply within the subfamily Abraeinae (sensu lato), and they are downgraded into Trypanaeini stat. n. and Trypeticini stat. n.

Congruence of morphological and molecular phylogenies of the rove beetle subfamily Staphylininae (Coleoptera: Staphylinidae).

Staphylininae is the third largest subfamily of the enormous family Staphylinidae. Monophyly of Staphylininae and its sister relationship to the subfamily Paederinae have been broadly accepted according to both conventional morphology- and molecular-based phylogenies until the last three years. Recent molecular phylogenies rejected monophyly of Staphylininae and regarded Paederinae as a clade within it. This paper re-evaluates the recent molecular work, aiming to clarify the relationship between Staphylininae and Paederinae and resolve intertribal relationships within Staphylininae. Based on a new six-gene data set (5707 bp) for 92 taxa including Oxyporinae (outgroup), representatives of Paederinae, and members of all extant tribes of Staphylininae from published DNA data in GenBank, we generated a well-resolved phylogeny of Staphylininae with all deep nodes (intertribal relationships) strongly supported, and reassert the hypothesis that Staphylininae is monophyletic and indeed the sister group to Paederinae using both Bayesian and maximum likelihood inference. Additionally, our study is a case-study to show that both outgroup selection and completeness of nucleotide data can influence the outcome of a molecular phylogeny. With an increasing number of staphylinid fossils being discovered, the robust phylogeny of Staphylininae inferred by our research will provide a good framework for understanding the early evolution of this group.

A Mesozoic clown beetle myrmecophile (Coleoptera: Histeridae).

Complex interspecies relationships are widespread among metazoans, but the evolutionary history of these lifestyles is poorly understood. We describe a fossil beetle in 99-million-year-old Burmese amber that we infer to have been a social impostor of the earliest-known ant colonies. Promyrmister kistneri gen. et sp. nov. belongs to the haeteriine clown beetles (Coleoptera: Histeridae), a major clade of 'myrmecophiles'-specialized nest intruders with dramatic anatomical, chemical and behavioral adaptations for colony infiltration. Promyrmister reveals that myrmecophiles evolved close to the emergence of ant eusociality, in colonies of stem-group ants that predominate Burmese amber, or with cryptic crown-group ants that remain largely unknown at this time. The clown beetle-ant relationship has been maintained ever since by the beetles host-switching to numerous modern ant genera, ultimately diversifying into one of the largest radiations of symbiotic animals. We infer that obligate behavioral symbioses can evolve relatively rapidly, and be sustained over deep time.

Taxonomy of the genus Diochus Erichson, 1839 (Coleoptera: Staphylinidae, Staphylininae, Diochini) in China with descriptions of four new species.

This paper studies the taxonomy of the genus Diochus Erichson, 1839 (Coleoptera: Staphylinidae, Staphylininae, Diochini) from China. Four new species are described: Diochus bicornutus sp. nov. from Fujian, Hainan, Zhejiang, Guangxi and Yunnan, D. ampullaceus sp. nov. from Guangxi, D. bisegmentatus sp. nov. from Hainan and Yunnan, and D. membranaceus sp. nov. from Fujian. All other species previously reported from China are redescribed based on the examination of the holotypes, except the holotype of D. antennatus (Motschulsky, 1858), which was missing. Line drawings of the now missing holotype of D. antennatus (Motschulsky, 1858) are provided. A lectotype is designated for D. conicollis (Motschulsky, 1858). The Chinese fauna of the genus Diochus is now represented by eight species (four doubtfully recorded) and a key to all the Chinese species is provided. The type specimens of the new species are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZ-CAS).

Taxonomy of the genus Erymus Bordoni (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) in China with descriptions of two new species.

This paper studies the taxonomy of the genus Erymus Bordoni, 2002 (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) from China. Two new species are described: Erymus wufengensis sp. n. from Hubei, and E. gilvus sp. n. from Hainan, Guangxi, and Guangdong provinces of China. The previously known four species of this genus are redescribed, and the identification key to all six Chinese species of the genus is provided. The type specimens of the new species are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZ-CAS).

Taxonomy of the genus Megalinus Mulsant & Rey (Coleoptera: Staphylinidae, Xantholinini) and seven new species from China.

This paper studies the taxonomy of the genus Megalinus Mulsant & Rey, 1877 (Coleoptera: Staphylinidae, Xantholinini)and offers a comprehensive revision of the Chinese fauna. Seven new species are described: Megalinus ailaoshanensis Zhou & Zhou sp. nov. from Yunnan, M. hailuogouensis Bordoni sp. nov. from Sichuan, M. liupanshanensis Zhou & Zhou sp. nov. from Ningxia, M. ningxiaensis Bordoni sp. nov. from Ningxia, M. nonvaricosus Zhou & Zhou sp. nov.from Ningxia, M. solidus Zhou & Zhou sp. nov. from Hainan and Yunnan, and M. tangi Bordoni sp. nov. from Xizang. The taxonomic status of M. leishanensis (Bordoni, 2007) is reinstated and treated as a valid species here. The following new synonym is proposed: M. suffusus (Sharp, 1874) = L. flavoelytratus (Bordoni, 2007) syn. nov. Three species originally described in Chinese are redescribed here: M. cinnamomeus (Zheng, 1994), M. coracinus (Zheng, 1994) andM. zhenyuanensis (Zheng, 1994). Therefore the Chinese fauna of the genus Megalinus is now represented by a total of 33 species. A key to all Chinese species is provided.

Two new species of Xanthophius Motschulsky (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) from China with notes on X. filum (Kraatz).

This paper studies the taxonomy of the genus Xanthophius Motschulsky, 1860 (Coleoptera: Staphylinidae, Staphylininae, Xantholinini). Two new species are described from China: Xanthophius unicidentatus sp. n. from Yunnan, Zhejiang, Guangxi and Hainan, and X. gutianshanensis sp. n. from Zhejiang. The number of species of Xanthophius therefore increased to eight. The elaborate structures of the everted endophallus of X. filum (Kraatz, 1859) is described for the first time and illustrated with a color plate. A key to eight species and their geographical distribution map are provided. The type specimens of the new species are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZ-CAS).

Taxonomy of the genus Metolinus Cameron (Coleoptera, Staphylinidae, Staphylininae, Xantholinini) from China with description of three new species.

This paper studies the taxonomy of the genus Metolinus Cameron, 1920 (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) from China and describes three new species: Metolinus xizangensissp. n. from Xizang (Tibet), Metolinus emarginatussp. n. fromSichuan, and Metolinus binariussp. n. from Yunnan. The Chinese fauna of the genus is thus increased to 8 species in total. A key to eight Chinese species is provided. Female genital segments and other important morphological characters are illustrated in line drawings for the new species as well as Metolinus shanicus Bordoni, 2002 and Metolinus gardneri (Cameron, 1945). The text also provides color plates with habitus photographs and a map to show the species' geographical distribution pattern. The type specimens of the new species are deposited in Institute of Zoology, the Chinese Academy of Sciences (IZ-CAS).