Taxonomic revalidation of Selenobrachys Schmidt, 1999 and Chilocosmia Schmidt & von Wirth, 1992 based on morphological and molecular analyses (Araneae, Theraphosidae), with the description of a new species from Romblon Island, Philippines

Abstract

Selenobrachys Schmidt, 1999 and Chilocosmia Schmidt & von Wirth, 1992 were considered junior synonyms to Orphnaecus Simon, 1892 without further morphological investigation nor the use of molecular methods of analysis. Herein, the type specimens are reexamined with newly collected samples of currently known Orphnaecus species, including new specimens from Romblon Island, Philippines. Morphological and molecular analyses were performed, utilizing cytochrome oxidase I (COI) and ribosomal genes (12 S – tRNA-Val – 16 S).

Synapomorphies in the structure of maxillary lyra, spermathecae, and male palpal morphology were observed in O. philippinus and the Romblon specimen which are distinct from other Orphnaecus species. In addition, lyrate morphology, setae structure on the patella of palp dorsal, and the male palpal organ morphology of O. dichromatus differ from other Orphnaecus species. Cladistic separation observed in molecular phylogenetic analyses supports morphological observations.

Our findings suggest that the genus Selenobrachys is distinct from Orphnaecus; hence, the genus Selenobrachys Schmidt, 1999, stat. rev. and its type species Selenobrachys philippinus Schmidt, 1999, comb. rest., are restored and the new species from Romblon Island, Selenobrachys ustromsupasius sp. nov., be identified as the second Selenobrachys species. Furthermore, the genus Chilocosmia Schmidt & von Wirth, 1992, stat. rev. and the original combination of its type species, Chilocosmia dichromata Schmidt & von Wirth, 1992, comb. rest. are restored.

Male specimens of S. philippinus and C. dichromata were described for the first time. Insights on the biogeography of Philippine tarantulas are discussed.