Type host:Spermophilus undulatus.

Type locality: North America: Canada, Yukon Territory, Kluane Lake area, mile 1054 of the Alaskan Highway.

Description of oocyst: Oocyst shape: elongate-ellipsoid; wall thickness: 0.6; layers: 2; outer layer proportion of total thickness: 0.8; outer layer colour: brownish-yellow; outer layer texture: smooth; inner wall characteristics: smooth, colourless; micropyle: present; micropyle width: ~2; MC: absent; OR: absent; PG: absent; size: 24.5 x 13.3 (21-27 x 12-15); L/W ratio: 1.8 (1.5-2.1). Distinctive features of oocyst: inner membrane often appears wrinkled at the micropylar end; flattened micropyle.

Description of sporocysts and sporozoites: Sporocyst shape: ovoid; size: 10.9 x 5.9 (9-12 x 5-6); SB: present; SB L x W: not given; SB characteristics: distinct, appears button-like (in drawing); SSB: absent; PSB: absent; SR: present; SR characteristics: ellipsoid to spheroid, bound by a thin membrane, comprised of granules of various sizes; SR size: 4 x 3; SP: elongate with 1 end narrower than the other, lie head to tail, and have an ellipsoid RB at broad end. Distinctive features of sporocyst: none.

Remarks: Eimeria yukonensis has been observed only once (Sampson, 1969).

Reference: Sampson (1969).