A new species of Brachistosternus from Chile

 

 The unique geography of Chile is the origin of pockets of endemic species. Andres Ojanguren-Affilastro and co-workers have recently described a new species of Brachistosternus Pocock, 1893 (Bothriuridae) from the upper basin of the Maule Valley, located in the Maule Region of central Chile.

Brachistosternus pehuenche Ojanguren Affilastro, Alfaro, Iuri, Camousseigt-Montolivo & Pizarro-Araya, 2025

Abstract:
Brachistosternus pehuenche sp. nov. (Scorpiones, Bothriuridae) is described from the Mauline Andean forests of the northern Chilean Patagonia, located within the upper basin of the Maule Valley. Its unique geography and the discovery of this partial isolation, as a result of the surrounding higher altitudes, support the role of this valley as a biodiversity hotspot, fostering a variety of endemic epigean arthropods. The discovery of this third endemic scorpion species highlights the area’s ecological uniqueness. The species is most similar to Brachistosternus negrei, a species found in the southern Chilean forests, but distinct morphological traits, such as pigmentation patterns and metasomal structures, clearly separate the two. This study underscores the ecological value of the Maule Valley, which, despite its high endemism, remains unprotected and is subject to significant anthropogenic pressures, including agriculture, hydropower projects, and international transit routes. The need for conservation initiatives in this region is critical to preserve its exceptional biodiversity. This work not only adds to the taxonomy of Brachistosternus but also raises fundamental questions about the processes driving endemism in the Andes and the broader implications for the conservation of montane ecosystems.

Reference:
Ojanguren-Affilastro AA, Alfaro FM, Iuri HA, Camousseigt-Montolivo B, Pizarro-Araya J. Description of Brachistosternus pehuenche sp. nov. (Scorpiones, Bothriuridae), a new scorpion species from the upper Maule Valley, in the southern Chilean Andes. Zoosystematics and Evolution. 2025;101(3):969–81. [Open Access]

Thanks to Gerard, Matt and Victoria for informing me about this article!

Family Bothriuridae

A new cryptic species in the genus Brachistosternus from the Argentinean central Andes

 

Andres Ojanguren-Affilastro and co-workers have discovered a new species in the genus  Brachistosternus Pocock, 1893 (Bothriuridae) from the Argentinean central Andes. 

 Brachistosternus diaguita Ojanguren-Affilastro, 2023

The new, high-altitude species is a cryptic species that is very difficult to separate from other related species in the area. A phylogenetic analysis supports the status of the new genus.

Abstract:
In this contribution we describe Brachistosternus diaguita n. sp. from the Argentinean central Andes, which is closely related to Brachistosternus montanus Roig-Alsina 1977, also from the same region. To corroborate reciprocal monophyly of the species, Bayesian inference was carried out on a selection of taxa, for which three mitochondrial (16S rDNA, 12SrDNA and COI) and two nuclear (28S rDNA and 18S rDNA) gene fragments had previously been sequenced for previous contributions on this genus by our group. Finally, we explored the potential distribution of Argentinean high Andean species of this genus using Maxent.

Reference:
Ojanguren-Affilastro AA, Ceccarelli FS, Mattoni CI, Salas L, Iuri H, Ochoa JA, et al. On the southernmost high Andean scorpion species, with the identification of a cryptic new species of Brachistosternus (Bothriuridae) through morphology, molecular data and species distribution models. Zoologischer Anzeiger. 2023;302:248–59. [Subscription required for full text]

Thanks to Andres for sending me their new article!

Family Bothriuridae

Two new species of Brachistosternus from high altitude habitats in Chile

 

The deserts in northern Chile have a high scorpion diversity, but many parts of this region are not yet fully investigated. Andres Ojanguren-Affilastro and co-workers have recently publish an article describing two new species of  Brachistosternus Pocock, 1893 (Bothriruidae) from high altitude habitats in the Antofagasta Region in Chile.

Brachistosternus chimba Ojanguren Affilastro, Alfaro & Pizarro-Araya, 2021

Brachistosternus llullaillaco Ojanguren Affilastro, Alfaro & Pizarro-Araya, 2021

Abstract:
We describe two new scorpion species of genus Brachistosternus from protected areas of Antofagasta Region in northern Chile. Brachistosternus chimba n. sp. has only been collected in La Chimba National Reserve, in the Chilean Coast Range. Brachistosternus llullaillaco n. sp. is a high altitude Andean species of the Lullaillaco National Park. Both species were collected as part of the first survey of the terrestrial arthropods of the protected areas of Antofagasta Region, in the frame of the First National Biodiversity Inventory of Chile of the Integrated System for Monitoring and Evaluation of Native Forest Ecosystems (SIMEF) and Project FIC-R Recovery Plan for La Chimba National Reserve.

Reference:
Ojanguren Affilastro AA, Alfaro FM, Pizarro-Araya J. Two new scorpion species from protected areas in Antofagasta Region, Chile (Scorpiones, Bothriuridae, Brachistosternus). Zootaxa. 2021;5040(1):111-31. [Subscription required for full text]

Thanks to Matt Simon for informing me about this article and to Andres for sending it to me! 

Family Bothriuridae

Five new species of Brachistosternus from deserts in Chile and Peru

Andres Ojanguren-Affilastro and co-workers have published a new paper on the Brachistosternus Pocock, 1893 (Bothriuridae) fauna in deserts in Chile and Peru. Five new species are described.

Brachistosternus anandrovestigia Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Peru)

Brachistosternus contisuyu Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Peru)

Brachistosternus gayi Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Chile)

Brachistosternus misti Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Peru)

Brachistosternus philippii Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Chile)

Some diagnostic characters for the genus is also discussed.

Abstract:
Five new scorpion species of genus Brachistosternus of Chile and Peru are described. Brachistosternus gayi n. sp. is a high Andean species of north central Chile. Brachistosternus philippii n. sp. occurs near the coast of Antofagasta. Brachistosternus misti n. sp. occurs at intermediates altitudes of southern Peru. Brachistosternus contisuyu n. sp. occurs in Lomas formation in southern Peru. Brachistosternus anandrovestigia n. sp. occurs in coastal areas of southern Peru, and is the second known species of the genus without metasomal glands or androvestigia. Two diagnostic characters are discussed: the Internal Laminar Apophysis of the right hemispermatophore, and the sternum macrosetae.

Reference:
Ojanguren Affilastro AA, Pizarro-Araya J, Ochoa JA. Five new scorpion species of genus Brachistosternus (Scorpiones: Bothriuridae) from the deserts of Chile and Peru, with comments about some poorly studied diagnostic characters of the genus. Zootaxa. 2018;4531(2):151-94. [Subscription required for full text]

Thanks to Andrés Ojanguren-Affilastro for sending me their article!

Family Bothriuridae

Some biological aspects of the genus Brachistosternus in Chile

Andres Ojanguren Affilastro and co-workers recently published an article with new data on prey capture and habitat of the genus Brachistosternus Pocock, 1893 (Bothriruidae) in Chile. In addition, a new type of pedipalp macroseta was described.

Abstract:
New data about several aspects of the biology of scorpions of genus Brachistosternus of the Atacama Desert are provided. Predatory techniques on tenebrionid larvae, and large spiders in their burrows are described, as well as the method used to transport large preys. The habitat of Brachistosternus mattonii Ojanguren-Affilastro 2005, by the tide line, is described for the first time. Finally a new type of pedipalp macroseta of Bothriuridae is described.

Reference:
Ojanguren Affilastro AA, Botero-Trujillo R, Castex A, Pizarro-Araya J. Biological aspects of the genus Brachistosternus (Bothriuridae) in the Atacama Desert (Chile), with the description of a new type of pedipalp macroseta. Gayana. 2016;80(2):169-74. [Open Access]

Thanks to Andres Ojanguren Affilastro for sending me their paper!

Phylogeography and population structure of two Brachistosternus species from Chile

Sara Ceccarelli and co-workers have recently published an article looking into the phylogeography and population structure of two species of Brachistosternus Pocock, 1893 (Bothriuridae) from costal deserts of Chile.

Abstract:
Coastal deserts are geologically dynamic areas of the Earth, affected by historical changes in sea levels and in some cases also by fault-line tectonic activity. An example of such a dynamic area is the Chilean coastal desert of the Antofagasta and Atacama regions, which harbours many endemic species, such as the bothriurid scorpion species Brachistosternus paposo and Brachistosternus roigalsinai. In this work, we carry out phylogeographic and population genetic analyses on these scorpions, using two mitochondrial (COI and cyt b) and two nuclear (Actin 5C and wingless) markers to identify species and population structuring, and link these findings to the geological history of the area. The geographical feature separating the two species is identified as the Huasco River, and distinguishing morphological features for these scorpions are presented. Population genetic and phylogeographic outcomes reflect an unstable history across this region for B. paposo and B. roigalsinai, related to sea-level changes affecting coastal habitats, including nearby islands.

Reference:
Ceccarelli FS, Pizarro‐Araya J, Ojanguren‐Affilastro AA. Phylogeography and population structure of two Brachistosternus species (Scorpiones: Bothriuridae) from the Chilean coastal desert–the perils of coastal living. Biological Journal of the Linnean Society. 2016;Early View Article. [Subscription required for full text]

Thanks to Andres Ojanguren-Afillastro for sending me this article!

What role had the formation of the Andes mountain range on the speciation in the genus Brachistosternus?

The Andes continental mountain chain in South America is one of the worlds longest, and the formation of this mountain chain (The Andean uplift) probably had a major impact of the evolution of plants and animals in this region. The bothriurid genus Brachistosternus Pocock,1893 is endemic to South America and distributed mainly in the Andean region. In a recent article, Sara Ceccarelli and co-workers have investigated the biogeographical history of Brachistosternus to determine the role of Andean uplift on the distribution and diversification of its species.

It is no surprise that this study confirms that the evolution and diversification of Brachistosternus was very much influenced by the major geological changes caused by the Andean uplift.

Abstract:
Aim 
One of the planet’s most imposing geomorphological features, the Andes, played an important role in the evolution of South America’s flora and fauna. The bothriurid scorpion genus Brachistosternus Pocock, 1893 comprises more than 40 species with high diversity and endemism in the Andes. The present contribution investigates the biogeographical history of this genus using molecular phylogenetics and dating, to determine the role of Andean uplift on the distribution and diversification of its species. 
Location 
South America.
Methods 
A dated species tree was obtained for 55 putative species based on two nuclear and three mitochondrial gene loci. Ancestral ranges and biogeographical events were estimated on the species tree, diversification rates and rate shifts calculated, and areas with high phylogenetic diversity (PD) and evolutionary distinctiveness identified.
Results 
Brachistosternus diversified at a steady rate during the main Andean uplift. The central Andean and western slope/Pacific coastal biogeographical provinces played important roles as ancestral areas. Coastal areas of central Chile and southern Peru exhibit high levels of PD in Brachistosternus, suggesting they experienced a relatively long period of ecological stability, while the Andes continued to rise.
Main conclusions 
Andean uplift created new habitats and climate regimes, favouring speciation in genera such as Brachistosternus. Coastal areas to the west of the Andes continued to harbour older lineages while accommodating more recently diverged lineages from the nearby Andes.

Reference:
Ceccarelli FS, Ojanguren-Affilastro AA, Ramırez MJ, Ochoa JA, Mattoni CI, Prendini L. Andean uplift drives diversification of the bothriurid scorpion genus Brachistosternus. Journal of Biogeography. 2016;Epub 13 May 2016. [Subscription required for full text]

Thanks to Andres Ojanguren-Affilastro for sending me their article!

The first phylogenetic analysis of the genus Brachistosternus based on molecular and morphological data has been published

Brachistosternus Pocock, 1893 (Bothriuridae) is a very abundant taxa in most arid to semi-arid habitats of southern and western South America. Andres Ojanguren-Affilastro and co-workers have recently published the first phylogenetic analysis of Brachistosternus based on molecular and morphological data.

See abstract and article for further details.

Abstract:
A phylogenetic analysis of the scorpion genus Brachistosternus Pocock, 1893 (Bothriuridae Simon, 1880) is presented, based on a dataset including 41 of the 43 described species and five outgroups, 116 morphological characters and more than 4150 base-pairs of DNA sequence from the nuclear 18S rDNA and 28S rDNA gene loci, and the mitochondrial 12S rDNA, 16S rDNA, and Cytochrome c Oxidase Subunit I gene loci. Analyses conducted using parsimony, Maximum Likelihood and Bayesian Inference were largely congruent with high support for most clades. The results confirmed the monophyly of Brachistosternus, the nominal subgenus, and subgenus Ministernus Francke, 1985, as in previous analyses based only on morphology, but differed in several other respects. Species from the plains of the Atacama Desert diverged basally whereas the high altitude Andean species radiated from a more derived ancestor, presumably as a consequence of Andean uplift and associated changes in climate. Species limits were assessed among species that contain intraspecific variation (e.g., different morphs), are difficult to separate morphologically, and/or exhibit widespread or disjunct distributions. The extent of convergence in morphological adaptation to life on sandy substrata (psammophily) and the complexity of the male genitalia, or hemispermatophores, was investigated. Psammophily evolved on at least four independent occasions. The lobe regions of the hemispermatophore increased in complexity on three independent occasions, and decreased in complexity on another three independent occasions.

Reference:
Ojanguren-Affilastro AA, Mattoni CI, Ochoa JA, Ramirez MJ, Ceccarelli FS, Prendini L. Phylogeny, species delimitation and convergence in the South American bothriurid scorpion genus Brachistosternus Pocock 1893: Integrating morphology, nuclear and mitochondrial DNA. Mol Phylogenet Evol. 2015 Aug 28;94(Pt A):159-70. [Subscription required for full text]

Thanks to Victor Fet and Andres Ojanguren for both sending me this article!

Family Bothriuridae

Two new species of Brachistosternus from Chile

Andres Ojanguren Affilastro & Jaime Pizarro-Araya have recently published a paper describing two new species of Brachistosternus Pocock, 1893 (Bothriuridae) from the Coastal desert of Taltal in Chile.

Brachistosternus barrigai Ojanguren Affilastro & Pizarro-Araya, 2014
Brachistosternus paposo Ojanguren Affilastro & Pizarro-Araya, 2014

Abstract:
Brachistosternus paposo n. sp. and Brachistosternus barrigai n. sp. are described from Paposo, in the coastal transitional desert of northern Chile. Brachistosternus paposo n. sp. is closely related to Brachistosternus roigalsinai Ojanguren Affilastro 2002, and B. barrigai n. sp. is closely related with Brachistosternus kamanchaca Ojanguren-Affilastro, Mattoni & Prendini 2007.

Reference:
Ojanguren Affilastro AA, Pizarro-Araya J. Two new scorpion species from Paposo, in the Coastal desert of Taltal, Chile (Scorpiones, Bothriuridae, Brachistosternus). Zootaxa. 2014;3785(3):400-18. [Subscription required for full text]

Thanks to Andres Ojanguren-Affilastro for sending me their paper!

Family Bothriuridae

A phylogenetic analysis of the South American genus Brachistosternus

Andres Ojanguren-Affilastro & Martin J. Ramirez has recently published a major phylogenetic analysis of the South American genus Brachistosternus (Bothriuridae). The authors have been able to investigate 38 of the 41 known species in the genus. The conclusions of the analysis can be seen in the abstract cited below (but in addition I will mention that Brachistosternus holmbergi Carbonell, 1923 is considered nomen dubium by the authors).

In addition to the phylogenetic analysis, the article also presents data on the distribution of the genus and an identification key for all species in the genus.

Abstract:
A phylogenetic analysis of the scorpion genus Brachistosternus Pocock (Bothriuridae) is presented. The analysis is based on a data set including 38 of the 41 described species of Brachistosternus plus eight outgroup representatives of seven additional bothriurid genera and one buthid, scored for 116 morphological characters. The cladistic analysis of this matrix under implied weighting results in four most parsimonious trees. The monophyly of genus Brachistosternus is well supported; its subgeneric subdivision is redefined: the subgenera Brachistosternus Pocock and Ministernus Francke are considered valid, whereas Leptosternus Maury is synonymized with Brachistosternus. Illustrations of diagnostic structures are provided. The hemispermatophores of Brachistosternus peruvianus Toledo-Piza and Brachistosternus pegnai Cekalovic are illustrated for the first time. A key to species of Brachistosternus and maps with the distribution of the subgenera and main groups of species are provided.

Reference:
Ojanguren-Affilastro AA, Ramirez MJ. Phylogenetic analysis of the scorpion genus Brachistosternus (Arachnida, Scorpiones, Bothriuridae). Zoologica Scripta. 2009 Mar;38(2):183-98. [Subscription required for fulltext]

Family Bothriuridae