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

The taxonomy and the systematics of the genus 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, 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 , which, however, might not be as close as usually assumed.