The synonymy of Gynaecotyla jaegerskioeldi (Travassos, 1920) Yamaguti, 1939 with Gynaecotyla adunca (Linton, 1905) Yamaguti, 1939 is confirmed, on the basis of the detailed morphological study of the cornucotyle of specimens of both referred species. The cornucotyle is a hermaphroditic organ that can be formed by the ovijector and the ejaculatory duct and is an important specific diagnostic character.
Birds; Brazil; cornucotyle; mammals; morphology; trematodes