Back from the deaf: integrative taxonomy revalidates an earless and mute species, Hylodes grandoculis van Lidth de Jeude, 1904, and confirms a new species of Pristimantis Jiménez de la Espada, 1870 (Anura: Strabomantidae) from the Eastern Guiana Shield

Abstract

Many anuran species remain to be formally named and described in Amazonia, notably in the Guiana Shield, and particularly in megadiverse groups such as Pristimantis. Several species in the Guiana Shield region have been confused with Pristimantis marmoratus and P. ockendeni. Hylodes grandoculis, a taxon previously placed in the synonymy of P. marmoratus, may be available for one of these species. To disentangle this confusing situation, we examined the external morphology and osteology (via µ-CT scans) of the holotype of H. grandoculis, the holotype of Pristimantis marmoratus, and of recently collected material for which we also analyzed molecular, acoustic, and morphological variation. We concluded that some populations from Suriname and northern Pará, Brazil, are distinct from P. marmoratus and correspond to Pristimantis grandoculis. Other populations, from French Guiana, are closely related to P. grandoculis but their status remains ambiguous. Finally, some populations, from French Guiana and Amapá, Brazil, are conspicuously distinct from both P. marmoratus and P. grandoculis and are described herein as P. crepitaculus sp. nov. A third species, belonging to a “trans-amazon complex”, occurs in southern Suriname, Guyana, and Brazil and remains undescribed. Pristimantis grandoculis and related populations from French Guiana lack external tympanum, columella, pharyngeal ostia, vocal slits and do not vocalize. This represents a rare, perhaps unique, example of a deaf and mute species of frogs from the Amazonian lowlands. © 2022, Gesellschaft für Biologische Systematik.