A chelicera-bearing arthropod reveals the Cambrian origin of chelicerates

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  A chelicera-bearing arthropod reveals the Cambrian origin of chelicerates Abstract Chelicerata is a megadiverse (over 120,000 species) arthropod clade that includes familiar taxa of profound ecological and economic importance, such as scorpions, spiders and mites 1 . Extant chelicerates share a unique anatomical character, the chelicerae—feeding first appendages terminated by a simple pincer-like chela 2 . The fossil record of these primarily predatory animals spans almost 500 million years 3 , suggesting a likely yet undocumented origin during the Cambrian Explosion. Artiopods 4 , 5 , 6 , megacheirans 4 , 7 , 8 , 9 , habeliids 10 , 11 , 12 , 13  and mollisoniids 14 , 15  have been considered Cambrian stem- or crown-group chelicerates, but they all lack unequivocal chelicerae, leaving the emergence of chelicerae-bearing arthropods unclear. Here we describe  Megachelicerax cousteaui  gen. et sp. nov., a large soft-bodied arthropod from the middle Cambrian of Ut...

Mygalomorphae spiders (Araneae) recorded by the Sistema de Notificação de Animais Peçonhentos (SINAP) in the state of Paraná

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Mygalomorphae spiders (Araneae) recorded by the Sistema de Notificação de Animais Peçonhentos (SINAP) in the state of Paraná

ABSTRACT

Despite their large size and intimidating appearance, most mygalomorph spiders do not cause severe envenomation in Brazil. “Programa Estadual de Vigilância de Acidentes por Animais Peçonhentos da Secretaria de Estado da Saúde do Paraná”, through the “Sistema de Notificação de Animais Peçonhentos” (SINAP), documents the occurrence of synanthropic species captured by the public and reported to municipal health services. In this study, we present a list of the mygalomorph species received by Secretaria de Saúde do Estado do Paraná (SESA) and their distribution across the state of Paraná, based on the SINAP reports. A total of 575 mygalomorph specimens were identified, originating from all 22 Regional Health Centers (RS) of SESA-PR. We identified species of four families: Actinopodidae (on species: Actinopus itapitocai); Dipluridae (1 species: Diplura catharinensis; Pycnothelidae (two species: Psalistopoides emanueli, and P. fulvimanus); and Theraphosidae (10 species in four genera: Acanthoscurria paulensis, Eupalaestrus campestratus, Grammostola actaeon, Pterinopelma longisternale, Tekoapora wacketi, Vitalius dubius, V. lucasae, V. paranaensis, V. sorocabae and V. vellutinus). Of the aforementioned species, Vitalius paranaensis has the widest distribution, occurring in all Regional Centers of Health except Paranaguá. The other most frequently collected species were Pterinopelma longisternale, Vitalius sorocabae, and Psalistopoides emanueli. In total, the 575 records resulted in only 12 accidents. The results highlight the broad distribution of some species; contributes to the identification of the main species encountered by the population and reported to SINAP in Paraná; and helps to bring attention to the low number of accidents caused by these large-sized spiders.

Brescovit, A. D., Lucas, S. M., Iniesta, L. F. M., & Marques-da-Silva, E.. (2024). Mygalomorphae spiders (Araneae) recorded by the Sistema de Notificação de Animais Peçonhentos (SINAP) in the state of Paraná. Zoologia (curitiba), 41, e23051. https://doi.org/10.1590/S1984-4689.v41.e23051