There are two morph species of ''T. circumcincta''; ''T. davtiani'' and ''Ostertagia trifurcata'', both of which have slightly different microscopic appearances to the ''T. circumcincta''. In males the bursa is longer in both species and the spicules, shorter and broader. | There are two morph species of ''T. circumcincta''; ''T. davtiani'' and ''Ostertagia trifurcata'', both of which have slightly different microscopic appearances to the ''T. circumcincta''. In males the bursa is longer in both species and the spicules, shorter and broader. |