The family Onchulidae: establishment of monophyly, rediagnosis, review and keys, with descriptions of three new species
Keywords:Africa, Limonchulus, morphology, Onchulus, systematics, Tobrilidae, Tobriloides
This paper presents a complete overview and monophyletic classification of the family Onchulidae. Thefamily is reviewed and rediagnosed, with the presence of alternating discs of glandular and muscular tissue in the oesophagus the primary feature uniting taxa of the family. Under this definition, the genus
Tobriloides Loof, 1973 — formerly Tobrilidae -- is included. The structure of the dorsal tooth and tail are the distinguishing features of two new subfamilies: Pseudonchulinae n. subfam. and Onchulinae n. subfam. The buccal armature other than the dorsal tooth is the defining characteristic of genera: the genus Paronchulus Altherr, 1972 is synonymized with Limonchulus Andrássy, 1963, and Cyathonchus Cobb, 1933 is treated as genus incertae sedis. Amended descriptions of all taxa are presented with a diagnostic key to subfamilies, genera and species in the family, a checklist of species and descriptions of three new species from moist tropical forest. Onchulus biannulatus sp. n. is characterised by its small body size, two prominent cuticular rings in the stoma, anterior amphid aperture, V’ =57- 65%, adult females with empty spermathecae, and absence of males. Onchulus microdontus sp. n. is characterised by its very small body size, lightly sclerotized dorsal stoma and relatively small dorsal tooth, anterior amphid aperture, a large value of De Man’s b and b’, V’ less than 57%, adult females with empty spermathecae, and males absent. Limonchulus denticulatus sp. n. is characterised by its small size, stoma lacking sclerotized rings, anterior amphid aperture, cervical papillae absent in females, and empty spermathecae.