Refine
Document Type
- Article (2)
- Part of Periodical (2)
Language
- English (4)
Has Fulltext
- yes (4)
Is part of the Bibliography
- no (4)
Keywords
- Africa (1)
- Atlantic Ocean (1)
- Biological Species Concept (1)
- Circellium (1)
- Glaphyrocanthon (1)
- Neotropics (1)
- New World (1)
- Novo Mundo (1)
- Scarabaeini (1)
- Scarabaeoidea (1)
Streblopus Van Lansberge, 1874 has been one of the most mysterious dung beetle groups of the Neotropical fauna, having a rather peculiar morphology, very few known specimens in collections and a difficult placement among the scarabaeine lineages. In this work, based on the examination of a recently collected series of specimens and a synthesis of some scattered, but deeply valuable, information available in the literature, we readdress many of the questions posed by past authors. It is shown that Streblopus is a relict genus composed of two currently living species of widely disjunct distribution, namely S. opatroides Van Lansberge, 1874, from patches of Atlantic Forest in the Brazilian states of Bahia and Espírito Santo, and S. punctatus (Balthasar, 1938), known from a few localities across Sub-Andean humid forests in the Peruvian and Ecuadorian Amazon Forest. We redescribe both and present in detail the evidence pointing to their validity as two independent species; a discussion of their remarkable sexual dimorphism is also given. The biogeography of Streblopus in South America is addressed, and we conclude that the present disjunct distribution of the genus is a consequence of the retreat of the tropical forest corridors that once connected the Atlantic Forest to the Amazon Basin through the South American Dry Diagonal during several periods of the Neogene, particularly until the Middle Miocene. Finally, we propose an African origin for the genus based on its close phylogenetic relationship with a group of Old World taxa ‒ particularly Circellium Latreille, 1825 and Scarabaeini. Having diverged from those groups in the late Upper Cretaceous, we argue that the ancestor of Streblopus arrived in South America crossing the Atlantic Ocean by rafting. We present a synthesis of data from a wide variety of biological groups to support our ideas and contend that long-distance dispersal hypotheses should be taken more seriously by scarab beetle specialists.
Although extensively studied by different authors over the past 150 years, the taxonomy of Canthon Hoffmannsegg, 1817 and allied genera (which are here informally referred to as 'Canthon sensu lato') still remains problematic. With the aim of resolving some of the questions surrounding these taxa, the present work reviews the taxonomy of one of them, the genus Sylvicanthon Halffter & Martínez, 1977. As defined here, Sylvicanthon is distributed mainly throughout the vast areas of tropical rainforests in the Neotropical region and includes 15 species divided into two groups: the enkerlini group, with a single species, S. enkerlini (Martínez et al., 1964) comb. nov., and the candezei group, with five subgroups: the candezei subgroup, with S. candezei (Harold, 1869), S. genieri sp. nov. and S. foveiventris (Schmidt, 1920); the aequinoctialis subgroup, with S. aequinoctialis (Harold, 1868) comb. nov. and S. proseni (Martínez, 1949) stat. et comb. nov.; the bridarollii subgroup, with S. bridarollii (Martínez, 1949), S. seag sp. nov., S. edmondsi sp. nov. and S. attenboroughi sp. nov.; the furvus subgroup, with S. furvus (Schmidt, 1920), S. monnei sp. nov., S. mayri sp. nov. and S. obscurus (Schmidt, 1920); and the securus subgroup, with a single species, S. securus (Schmidt, 1920) comb. nov. Three species originally included in Sylvicanthon are here (re)transferred to Canthon: Canthon xanthopus Blanchard, 1846 and C. machadoi (Martínez & Pereira, 1967) comb. nov., as well as C. cobosi (Pereira & Martínez, 1960) stat. et comb. nov., which had been previously in synonymy under C. xanthopus. Descriptions, redescriptions, illustrations and comparative tables on the external morphology (including the genital capsule) of the genus and its species are presented, as well as a detailed discussion on their biogeography, comparative morphology, hypotheses on their phylogenetic relationships, data on natural history and a detailed historical revision of the classification of 'Canthon sensu lato'. Finally, we also discuss the socalled 'species problem' (i.e., the definition of the scientific term 'species') and its consequences to dung beetle taxonomy and favour the solution offered by the Biological Species Concept.
The species Canthidium alvarezi Martínez and Halffter, 1986 (Coleoptera: Scarabaeidae: Scarabaeinae) is transferred to the genus Ateuchus Weber, 1801, becoming Ateuchus alvarezi (Martínez and Halffter), new combination. Its relationship with other species in the genus is briefly discussed. The validity and ranking of the genus Lobidion Génier, 2010, originally described from a single female, is discussed based on the discovery of male specimens, which lead us to reclassify it as a monotypic subgenus of Ateuchus, becoming Ateuchus (Lobidion), new rank, with the only included species becoming Ateuchus (Lobidion) punctatissimus (Génier, 2010) new combination.
Venezuela’s diverse land ecosystems are grouped into four major regions (coast-islands, low plains, hills and mountains), ranging from sea level up to 4978 m. The Scarabaeinae (Scarabaeidae, Coleoptera) currently encompass 278 genera and 6837 species worldwide, but are poorly inventoried in Venezuela. We reviewed the literature and the material housed at the entomological collection of the Universidade Federal de Mato Grosso (CEMT), Cuiabá, Brazil, and found 32 genera and 149 species of dung beetles as certainly present in Venezuela. Twenty-four of these species are, as far as current knowledge goes, endemic to the country, while another 34 are restricted to Venezuela and the neighbouring countries of Colombia, Brazil, Trinidad and Tobago, and Guyana. Additionally, 36 species are deemed potential inhabitants of the country, whilst 14 others previously recorded in the literature as part of the Venezuelan fauna are here concluded not to be actually present there. Complete literature is listed for each genus and species, and information on type material, material examined, worldwide distribution, and Venezuelan records is also presented.