Taxonomy and Systematics of the Genus Makatinus Heyns, 1965 (Nematoda: Dorylaimida: Aporcelaimidae)

The taxonomy and the systematics of the genus Makatinus are discussed by means of the characterization of its morphological pattern and the first molecular (D2–D3 expansion segments of 28S rDNA) analysis of a representative of this taxon, Makatinus crassiformis from Costa Rica. The presence of two or more pairs of male ad-cloacal genital papillae is the most characteristic autapomorphy of the genus, but the status of its species on this concern differ among them. Both morphological and molecular data support a relationship with Aporcelaimellus, which, however, might not be as close as usually assumed. An emended diagnosis of the genus, a key to species identification, and a compendium of their morphometrics are provided. Makatinus siddiqii is regarded as species inquirenda, Makatinus simus is retained under Eudorylaimus, and Makatinus tritici becomes a junior synonym of Aporcelaimellus tritici.