A revision of the genus Xanthopygus Kraatz (Staphylinidae: Xanthopygina).

The genus Xanthopygus Kraatz 1857 sensu Chatzimanolis 2021 is revised and the distributional records for all species are updated. Lampropygus giganteus Bernhauer is shown to be a junior synonym of Staphylinus luctuosus Blanchard. Neotypes are designated for Belonuchus pexus Motschulsky and Xanthopygus oliveirae Lynch. Lectotypes are designated for Lampropygus major Bernhauer, Staphylinus xanthopygus Nordmann and Xanthopygus cacti Horn. Lampropygus giganteus Bernhauer is designated as the type of the subgenus Heteropygus Bernhauer, since the type designation by Blackwelder was invalid. Illustrations and a key are provided for all species in Xanthopygus.

Out of Xanthopygus (Coleoptera: Staphylinidae): escape from polyphyly.

Xanthopygus as currently defined is the largest genus in the subtribe Xanthopygina (Coleoptera: Staphylinidae: Staphylininae) with 40 described species. However, the genus is poorly defined, morphologically heterogeneous and previous studies have questioned whether it is a natural group. A morphological (51 characters) Bayesian phylogenetic analysis was performed to test whether Xanthopygus is a monophyletic group. The analysis indicated that Xanthopygus was polyphyletic, and therefore species were split into four different genera. Xanthopygusnigricornis Scheerpeltz was transferred to Oligotergus as Oligotergusnigricornis comb. nov. and Xanthopygusskalitzkyi (Bernhauer) was transferred to Styngetus as Styngetusskalitzkyi comb. nov. A new genus, Photinopygus gen. nov. was erected to accommodate the majority of the species previously in Xanthopygus and Xanthopygus sensu novo is used in a new restricted sense to accommodate the remaining species. Diagnostic features are provided to distinguish species in the genera Photinopygus and Xanthopygus from each other and all other Xanthopygina genera.

Even more new species, additional records, and a revised key for Philothalpus Kraatz (Coleoptera: Staphylinidae: Staphylininae).

Two species of Philothalpus Kraatz are described as new: P. anapodos n. sp. Chatzimanolis, from Madre de Dios, Peru and P. boreios n. sp. Chatzimanolis from El Salvador, Guatemala and Costa Rica. Additional distributional records are provided for P. asymmetros Chatzimanolis Ashe, P. bilobus Chatzimanolis Ashe, P. fervidus (Erichson), P. juanecoi Asenjo Ribeiro-Costa, P. mundus (Sharp) and P. rugosus Chatzimanolis Ashe. A revised identification key is provided that includes all species of Philothalpus.

Peripus, a new genus of Xanthopygina (Coleoptera: Staphylinidae) from South America.

We describe a new genus of Xanthopygina as Peripus gen. n. Chatzimanolis Hightower and include the following species: P. brunkei sp. n. Chatzimanolis Hightower, P. didontus sp. n. Chatzimanolis Hightower, P. madrededios sp. n. Chatzimanolis Hightower, and P. monodontus sp. n. Chatzimanolis Hightower. Peripus belongs in the Isanopus group of genera of Xanthopygina. We provide photographs, illustrations and a key for the identification of species.

Lendatus, a new genus of Xanthopygina (Coleoptera: Staphylinidae: Staphylininae) with description of three new species.

A new genus of Xanthopygina rove beetles is described here as Lendatus gen. nov. The new genus includes three new species: L. bolivianus sp. nov., described from Bolivia, L. philothalpiformis sp. nov. described from Costa Rica and Panama, and L. platys sp. nov. described from Bolivia, Colombia, Ecuador and Peru. Lendatus belongs to the Isanopus group of genera of Xanthopygina and can distinguished from all the genera based on the unique punctation on the pronotum and the long apical setae of the paramere. A key to the three species of Lendatus along with photographs and illustrations is provided for the identification of species.

A revision of Haematodes Laporte and Weiserianum Bernhauer (Coleoptera: Staphylinidae: Staphylininae: Xanthopygina).

The species of poorly known but charismatic genera Haematodes Laporte, 1835 and Weiserianum Bernhauer, 1927 are revised. Weiserianumsyn. nov. is considered a junior synonym of Haematodes, with Haematodes kuntzeni (Scheerpeltz, 1936) comb. nov.Weiserianum woltersi Bernhauer, 1927 syn. nov. is treated as a synonym of Haematodes tenuipes Kraatz, 1858. Haematodes myterossp. nov., is described from Paraguay and Brazil. As the type series of Haematodes bicolor Laporte, 1835 is considered lost, a neotype, selected from the original type locality is designated. We also designate a lectotype for H. tenuipes Kraatz, 1858 to stabilize nomenclature for this species, which is similar to H. myteros. As far as known, Haematodes is restricted to the southern Neotropical region and may be nest parasites within Acromyrmex and Atta ant nests as are species of the related genus Scariphaeus, but no direct observations are yet available. We provide a key to the four known species of Haematodes and illustrate their diagnostic features.

Dispersal of thermophilic beetles across the intercontinental Arctic forest belt during the early Eocene.

Massive biotic change occurred during the Eocene as the climate shifted from warm and equable to seasonal and latitudinally stratified. Mild winter temperatures across Arctic intercontinental land bridges permitted dispersal of frost-intolerant groups until the Eocene-Oligocene boundary, while trans-Arctic dispersal in thermophilic groups may have been limited to the early Eocene, especially during short-lived hyperthermals. Some of these lineages are now disjunct between continents of the northern hemisphere. Although Eocene climate change may have been one of the most important drivers of these ancient patterns in modern animal and plant distributions, its particular events are rarely implicated or correlated with group-specific climatic requirements. Here we explored the climatic and geological drivers of a particularly striking Neotropical-Oriental disjunct distribution in the rove beetle Bolitogyrus, a suspected Eocene relict. We integrated evidence from Eocene fossils, distributional and climate data, paleoclimate, paleogeography, and phylogenetic divergence dating to show that intercontinental dispersal of Bolitogyrus ceased in the early Eocene, consistent with the termination of conditions required by thermophilic lineages. These results provide new insight into the poorly known and short-lived Arctic forest community of the Early Eocene and its surviving lineages.

New species and synonymies in Xenopygus Bernhauer (Coleoptera: Staphylinidae: Staphylinini).

Two species are described as new in Xenopygus, X. davidi sp. n. and X. pycnos sp. n. Dysanellus (Leptodiastemus) excellens Bernhauer is transferred to Xenopygus as X. excellens comb. n. and the subgenus Leptodiastemus syn.n. is placed in synonymy with Xenopygus. Xenopygus sancticamillus Caron and Castro syn. n. is shown to be a junior synonym of X. excellens. Gastrisus punctatus Sharp is transferred to Xenopygus as X. punctatus comb. n. Gastrisus cribrum Fauvel syn. n. and X. petilicolis Caron and Castro syn. n. are shown to be junior synonyms of X. punctatus. Two informal species groups are proposed to accommodate the existing species in Xenopygus and an updated key is provided for the identification of the species.

A revision of the myrmecophilous genus Smilax Laporte (Coleoptera: Staphylinidae: Staphylininae).

The neotropical myrmecophilous genus Smilax is revised and a new species, Smilax deneinephyto Chatzimanolis is described from southern Brazil. Lectotypes are designated for Smilax cyanea Wasmann and Staphylinus pilosus Fabricius. Smilax cyanea is shown to be a junior synonym of Smilax pilosa. A key and illustration of morphological features are provided for the identification of taxa. The types of the two species of Smilax were not available for study even though they are deposited in public museums.

Early evolution of the hyperdiverse rove beetle tribe Staphylinini (Coleoptera: Staphylinidae: Staphylininae) and a revision of its higher classification.

The rove beetle tribe Staphylinini (Staphylinidae: Staphylininae) is a monophyletic lineage of over 5500 relatively large and charismatic species, yet its higher classification remains deeply rooted in historical concepts. Despite recent progress toward inferring phylogenetic relationships within this group using morphological and molecular datasets, relationships among taxa that were united under a polyphyletic "Quediina" remain largely unknown. To infer these relationships, we analysed a six-gene dataset (4370 bp) using parsimony and model-based analyses and the results were placed in the context of morphology. While all genes contributed synapomorphies for major lineages or relationships between them, carbamoyl synthetase (CAD), topoisomerase I (TP) and wingless (Wg) were the most informative. TP was generally most informative at the level of subtribe, Wg above this level and CAD throughout the tree. The monophyly of Staphylinini was strongly supported and analyses support seven clades that correspond to higher taxonomic levels, four of which are formally described as subtribes here: Acylophorina stat. rev., Cyrtoquediina new subtribe, Erichsoniina new subtribe and Indoquediina new subtribe. The majority of Staphylinini taxa were recovered within a well-supported "northern hemisphere clade" that is weakly represented in the southern hemisphere. The composition and morphological diagnosis of the "Staphylinini propria" clade are revised, and the pronotum shape historically associated with this group is shown to have evolved multiple times elsewhere in Staphylinini. The genus Stevensia is moved from Staphylinina to Acylophorina based on morphological evidence. Cyrtoquedius stat. nov., previously a subgenus of Quedius, is raised to the genus level. The following 32 new combinations (from Quedius) are proposed: Cyrtoquedius anthracinus (Solsky); C. arrogans (Sharp); C. basiventris (Sharp); C. bolivianus (Sharp); C. bruchi (Bernhauer); C. clypealis (Sharp); C. concolor (Sharp); C. flavicaudus (Sharp); C. flavinasis (Bernhauer); C. frenatus (Erichson); C. graciliventris (Sharp); C. jacobi (Scheerpeltz); C. jocosus (Sharp); C. labiatus (Erichson); C. laeviventris (Bernhauer); C. mexicanus (Sharp); C. ochropygus (Bernhauer); C. ogloblini (Bernhauer); C. ornatocollis (Bierig); C. protensus (Sharp); C. rufinasus (Sharp); C. verecundus (Sharp); C. verres (Smetana); Indoquedius borneensis (Cameron); I. dispersepunctatus (Scheerpeltz); I. javanus (Cameron); I. malaisei (Scheerpeltz); I. micantiventris (Scheerpeltz); I. parallelicollis (Scheerpeltz); I. philippinus (Cameron); I. recticollis (Scheerpeltz); and I. sanguinipennis (Scheerpeltz). Cyrtoquedius verres is recorded from the state of Georgia (USA) for the first time, which, together with its transfer from Quedius, extends the distribution of the Cyrtoquediina significantly northward into the Nearctic.

Sexual dimorphism and allometry in the sphecophilous rove beetle Triacrus dilatus.

The rove beetle Triacrus dilatus is found in the Atlantic forest of South America and lives in the refuse piles of the paper wasp Agelaia vicina. Adults of T. dilatus are among the largest rove beetles, frequently measuring over 3 cm, and exhibit remarkable variation in body size. To examine sexual dimorphism and allometric relationships we measured the length of the left mandible, ocular distance and elytra. We were interested in determining if there are quantifiable differences between sexes, if there are major and minor forms within each sex and if males exhibit mandibular allometry. For all variables, a t-test was run to determine if there were significant differences between the sexes. Linear regressions were run to examine if there were significant relationships between the different measurements. A heterogeneity of slopes test was used to determine if there were significant differences between males and females. Our results indicated that males had significantly larger mandibles and ocular distances than females, but the overall body length was not significantly different between the sexes. Unlike most insects, both sexes showed positive linear allometric relationships for mandible length and head size (as measured by the ocular distance). We found no evidence of major and minor forms in either sex.

A review of the genus Scaponopselaphus Scheerpeltz (Insecta: Coleoptera: Staphylinidae).

BACKGROUND: The genus Scaponopselaphus Scheerpeltz was originally described to accommodate the species Trigonopselaphusmutator Sharp. NEW INFORMATION: In this paper, I review Scaponopselaphus and describe a new species from Colombia as Scaponopselaphusdiaspartos n. sp. Illustrations are provided for the identification of specimens and the presence of spatulate setae on first mesotarsomere is shown to be a unique characteristic of Scaponopselaphus within Xanthopygina.

Additional records and male description of Nordus stomachoponos Chatzimanolis (Coleoptera, Staphylinidae, Staphylininae)

Nordus stomachoponos Chatzimanolis, 2004 is a Neotropical species previously known only by the female. The male of N. stomachoponos is described, and additional records on its distribution are provided.

Darwin's legacy to rove beetles (Coleoptera, Staphylinidae): A new genus and a new species, including materials collected on the Beagle's voyage.

A species of xanthopygine rove beetles is described and figured here as Darwinilus sedarisi gen. n. and sp. n. The holotype was collected by Charles Darwin in Bahía Blanca, Argentina on the Beagle's voyage. The contributions of Charles Darwin to rove beetle systematics are summarized briefly.

Terataki, a new genus of Staphylinini (Coleoptera: Staphylinidae: Staphylininae) from South America.

A new genus of Xanthopygina is described here as Terataki gen. n. and includes the following species: Te. badiipennis comb. n., Te. caterinoi sp. n., Te. erithracus comb. n. and Te. liliputanum comb. n. Lectotypes are designated for Creophilus badiipennis Nordmann, C. chloris Nordmann, C. erithracus Nordmann and Polyphematiana liliputana Bernhauer. Creophilus chloris is shown to be a junior synonym of C. erithracus and Trigonopselaphus nobilis Wendeler a junior synonym of C. badiipennis. A key and illustrations of structural features are provided for the identification of specimens. 

A new species of Diochus from Baltic amber (Coleoptera, Staphylinidae, Diochini).

The first fossil of the staphylinine tribe Diochini Casey is described and figured from an inclusion in mid-Eocene (Lutetian) Baltic amber. Diochus electrussp. n. is distinguished from its congeners and the diversity of rove beetles (Staphylinidae s.l.) is summarized briefly.

From gene-scale to genome-scale phylogenetics: the data flood in, but the challenges remain.

An important goal of phylogenetics is to be able to consistently and accurately reconstruct the historical patterns of cladogenesis among major organismic groups. Gene-scale phylogenetics is insufficient to attain this goal owing to the presence of poor resolution and incongruence in single--and few--gene phylogenies. The increasing availability of genome-scale amounts of data promises to overcome the insufficiency of gene-scale phylogenetics and uncover the genealogical tapestry uniting all living organisms with unprecedented accuracy. Here, we argue that a vast increase in data size alone--although necessary--may not be sufficient to achieve the desired accuracy for three reasons: (i) the existence of short stems in the tree of life, (ii) the saturation of phylogenetic signal in molecular sequences, and (iii) the effect of systematic error on phylogenetic inference. Devising strategies to ameliorate the effect of such challenges on sequence evolution will be critical to the success of current efforts to reconstruct the tree of life.

Toward a better understanding of the "Transverse Range break": lineage diversification in southern California.

The Transverse Ranges in southern California have been identified as having a prominent phylogeographic role. Numerous studies have identified distinct north-south and/or east-west lineage breaks involving the Transverse Ranges. However, in evaluating their findings, most authors have regarded this complex system somewhat simplistically. In this study we more deeply investigate these breaks using two approaches: first we examine the phylogeographic history of Sepedophilus castaneus (Coleoptera: Staphylinidae) and then implement a comparative phylogeography approach applying Brooks parsimony analysis to the topologies of nine additional taxa. Phylogenetic analysis, nested clade analysis, and AMOVAs for S. castaneus agree that there is a major lineage break between the eastern and western Transverse Ranges, localized between the Sierra Pelona and the San Gabriel Mountains. The comparative phylogeographic analysis supports a generally strong concordance of area relationships with geographic proximity. It is notable, however, that the Transverse Ranges as a group do not show phylogenetic cohesion, but rather they are split into three main regions: an eastern region (San Gabriel, San Bernardino, and San Jacinto Mountains), a central region (central Transverse Ranges and Sierra Pelona) that is often grouped with the Tehachapi and Sierra Nevada populations, and a western region (northwestern Transverse Ranges and Santa Ynez Mountains) that is consistently grouped with coast range areas to the north. The lineage break between east and west Transverse Ranges is attributable to the presence of a marine embayment in what is now the Santa Clara River valley 5-2.5 million years ago.