Onthophagus pilauco sp. nov. (Coleoptera, Scarabaeidae): evidence of beetle extinction in the Pleistocene-Holocene transition in Chilean Northern Patagonia.

The South American Pleistocene-Holocene transition has been characterized by drastic climatic and diversity changes. These rapid changes induced one of the largest and most recent extinctions in the megafauna at the continental scale. However, examples of the extinction of small animals (e.g., insects) are scarce, and the underlying causes of the extinction have been little studied. In this work, a new extinct dung beetle species is described from a late Pleistocene sequence (~15.2 k cal yr BP) at the paleoarcheological site Pilauco, Chilean Northern Patagonia. Based on morphological characters, this fossil is considered to belong to the genus Onthophagus Latreille, 1802 and named Onthophagus pilauco sp. nov. We carried out a comprehensive revision of related groups, and we analyzed the possible mechanism of diversification and extinction of this new species. We hypothesize that Onthophagus pilauco sp. nov. diversified as a member of the osculatii species-complex following migration processes related to the Great American Biotic Interchange (~3 Ma). The extinction of O. pilauco sp. nov. may be related to massive defaunation and climatic changes recorded in the Plesitocene-Holocene transition (12.8 k cal yr BP). This finding is the first record of this genus in Chile, and provides new evidence to support the collateral-extinction hypothesis related to the defaunation.

A new species and distribution records of Dichotomius Hope, 1838 (Coleoptera: Scarabaeidae: Scarabaeinae) in Colombia.

Dichotomius (Dichotomius) quadrilobatus new species (Coleoptera: Scarabaeidae: Scarabaeinae: Dichotomiini), from western Amazonia (Brazil, Colombia, Ecuador and Peru) is described and its putative systematic position within the Dichotomius boreus species group is discussed. An updated identification key to the species of the Dichotomius boreus species group is provided. Additionally, Dichotomius (Selenocopris) fortepunctatus Luederwaldt, 1923 is recorded for the first time in Colombia.

On the type species of the South American dung beetle genus Chalcocopris Burmeister, 1846 (Coleoptera: Scarabaeidae: Scarabaeinae), with some comments on the type locality of C. hesperus (Olivier, 1789).

Recently, a new paper authored by two of us (Rossini & Vaz-de-Mello, 2015) addressed a taxonomic revision of Chalcocopris Burmeister, 1846, describing a second species for the genus and expanding our knowledge of its distribution and morphological diversity. In the present work, we address additional nomenclatural and historical issues not covered in that paper.

A contribution to the knowledge of the mountain entomofauna of Mexico with a description of two new species of Onthophagus Latreille, 1802 (Coleoptera, Scarabaeidae, Scarabaeinae).

Recent intensive samplings carried out across the mountainous regions of El Pinal (Puebla, Mexico) have provided new insights into the main environmental factors that affect the geographic distribution of the scarabaeinae beetles of the Trans-Mexican Volcanic Belt above 2500 m a.s.l. This study is part of an ongoing project investigating the diversity and biogeography of copro-necrophagous beetles (Scarabaeinae, Aphodiinae, Geotrupinae and Silphidae) in the easternmost areas of the Trans-Mexican Volcanic Belt. Previous experience allows us to propose a series of predictions that we expect will provide possible explanations for current distribution patterns observed in Scarabaeinae and other groups of insects found in the Trans-Mexican Volcanic Belt. This mountain range has a primarily biogeographic importance, limiting the Mexican High Plateau in the South and connecting the western and eastern Sierra Madre mountain chains, which are considered the most important routes for dispersal of mountain fauna of northern origin. The taxonomic and biogeographic study of the species collected so far in El Pinal (including Onthophagus clavijeroisp. n. and Onthophagus martinpieraisp. n. described here), along with their possible relationships with other known species, allows us to answer the preliminary assumptions proposed.

ResumenCon base en capturas intensivas realizadas en la montaña de El Pinal (estado de Puebla, México) se plantea un análisis de los factores que intervienen en la distribución geográfica de la fauna de montaña (en este caso Scarabaeinae) por encima de los 2500 m de altitud, en el Sistema Volcánico Transversal (SVT), principal cordillera dispuesta en sentido latitudinal de México y de toda América. Este artículo es parte de una serie de trabajos coordinados para estudiar los escarabajos coprófagos y necrófagos de la parte oriental del SVT.La experiencia generada nos permite plantear una serie de premisas (Introducción) que se espera cumpla la distribución de la fauna de Scarabaeinae y de otros grupos en el SVT, cordillera de primera importancia biogeográfica, pues limita por el sur el Altiplano Mexicano (una península de Norte América) y une las dos principales cordilleras que se desarrollan N-S: las Sierras Madres Occidental y Oriental, las más importantes vías de penetración de la fauna de montaña de origen septentrional. Un análisis de las afinidades taxonómicas y biogeográficas de las colectas de Scarabaeinae en El Pinal (incluyendo dos especies nuevas de Onthophagus que se describen) nos permite dar respuesta en la Discusión a las premisas planteadas en la Introducción.

A review of the genus Chalcocopris Burmeister, 1846 (Coleoptera: Scarabaeidae: Scarabaeinae), with description of a new species.

Species included in the genus Chalcocopris Burmeister, 1846 are reviewed, including the description of a new species (Chalcocopris inexpectatus sp. nov.) from Central Brazil, and the designation of a neotype for Copris hesperus Olivier, 1789. Pictures, diagnostic characters and an identification key are provided.