Bioacoustics of Mimoscorpius

DIAGNOSIS: Mimoscorpius differs from all other whip scorpions on the basis of the following combination of characters. Carapace with pair of well-developed anterolateral carinae, extending from lateral ocelli approximately two-thirds towards median ocular tubercle. Median ocelli not separated by superciliary carina. Three pairs of lateral ocelli. Abdominal tergites II and III divided, with median longitudinal suture; IV and often V with partial suture; X divided laterally by pleuron; XII (anal) with pair of large, oval, laterally compressed ommatoids. Flagellar segments each with flagellar organs, situated anteroventrally. Sternite II (♂) with two inflated surfaces posterolaterally and posterior margin lobate medially. Seminal receptacle ( ♀ ) tubular, kidney-shaped, posteriorly directed. Pedipalps (♂) with long, cylindrical femur, almost twice length of patella; patellar apophysis long, slender; tibia enlarged proximally, forming ca . 45 ° angle with longitudinal axis. Leg tibiae IV, each with single ventrodistal spur. Mastigoproctus may be distinguished from Mimoscorpius on the basis of the following characters. The male pedipalp of Mimoscorpius is noticeably elongated, the trochanter dentition is not sexually dimorphic, and the tibia is almost as broad as long. The seminal receptacles of Mastigoproctus giganteus (Lucas, 1835) , the type species of the genus, are short, vertically and posteriorly directed. The median ocelli of Mastigoproctus are separated by a well-developed superciliary carina. Leg tibiae II–IV each possess a single ventrodistal spur in M. giganteus . Valeriophonus Víquez and Armas, 2005 , a monotypic genus endemic to Costa Rica , differs from Mimoscorpius based on the presence of a stridulatory organ, situated on opposing surfaces of the pedipalp coxa and the basal cheliceral segment, and the presence, on leg tibiae III and IV, of a single ventrodistal spur in each case. Valeriophonus is further distinguished from Mimoscorpius on the basis of its relatively short, robust pedipalp with a well-developed lobe on the external surface of the fixed finger, and the short, vertically- and anteriorly-directed seminal receptacles.