Composition. Worldwide, Agoliinus contains approximately 42 species, 25 of which occur in the New World.

Agoliinus albertanus (Brown 1928: 304) [Aphodius] , W-Canada, AK-USA.
Agoliinus aleutus (Eschscholz 1822: 27) [Aphodius], Siberia, NW-USA, W-Can.
                  = Aphodius ursinus Motschulsky 1845: 365.
Agoliinus anthracus Gordon and Skelley 2007: 133, SW-Canada, NW-USA.
                  = Aphodius anthracinus LeConte 1878: 455 [not Aphodius anthracinus W.                   Schmidt 1840].
Agoliinus aquilonarius (Brown 1928: 16) [Aphodius], NW-USA, SW-Canada.
Agoliinus ashworthi (Gordon 2006: 47-49) [Aphodius], SD to NM-USA.
Agoliinus bidentatus Schmidt 1907: 201 [?Aphodius], SW-Can, NW-USA.
                  = Aphodius bidens LeConte 1878: 453 [not Aphodius bidens Solsky 1876].
Agoliinus canadensis Garnett 1920: 139 [Aphodius], NW-USA, SW-Canada.
                  = Aphodius phaeopterus LeConte 1878: 456 [not Aphodius phaeopterus                   Stephens 1830].
                  = Aphodius russelli Hatch 1971: 452.
                  = Aphodius haywardi Brown 1928: 303.
Agoliinus congregatus (Mannerheim 1853: 219) [Aphodius], NW-N.America.
                  = Aphodius arcticus Harold 1863: 361.
                  = Aphodius richardsonae Hatch 1971: 452.
Agoliinus corruptor (Brown 1929: 206) [Aphodius], AK to NW-USA, W-Can.
                  = Aphodius explanatus Brown 1928: 13 [not Aphodius explanatus LeConte                   1878].
                  = Aphodius yukonensis Robinson 1948: 113.
                  = Aphodius calgaryensis Balthasar 1970: 249.
Agoliinus cruentatus (LeConte 1878: 456) [Aphodius], Mexico, SW-USA.
                  = Aphodius snowi Brown 1929: 209, SW-USA.
Agoliinus explanatus (LeConte 1878: 457) [Aphodius], ND to NM-USA.
Agoliinus guttatus (Eschscholz 1823: 97) [Aphodius], Canada, AK-USA.
Agoliinus hatchi Gordon and Skelley 2007: 138, NW-USA, BC-Canada.
                  = Aphodius angustus Hatch 1971: 452 [not Aphodius angustus Philippi and                   Philippi].
Agoliinus idahoensis Gordon and Skelley 2007: 162, NW-USA.
Agoliinus incommunis (Fall 1932: 186) [Aphodius], NW-USA, BC-Canada.
Agoliinus ingenursus Gordon and Skelley 2007: 140, CA-USA,
Agoliinus leopardus (Horn 1870: 124) [Aphodius], AK, NEastern-USA, Canada.
Agoliinus malkini (Hatch 1971: 453) [Aphodius], Idaho-USA.
Agoliinus manitobensis (Brown 1928: 302) [Aphodius], NE-USA to Mtba-Canada.
Agoliinus piceatus (Robinson 1946: 55) [Aphodius], AK, NW-USA, W-Canada.
                  = Aphodius rainieri Hatch 1971: 452.
Agoliinus plutonicus (Fall 1907: 245) [Aphodius], SW-USA, Mexico.
Agoliinus poudreus Gordon and Skelley 2007: 145, WY-USA.
Agoliinus praealtus Gordon and Skelley 2007: 145, NW-USA.
Agoliinus sigmoideus (VanDyke 1918: 9) [Aphodius], WA-USA, BC-Canada.
Agoliinus wickhami (Brown 1928: 301) [Aphodius], SW-Canada, NW-USA.

Life History. The majority of species appear to be boreal or high elevation generalists. Members with explanate pronota appear to be rodent burrow specialists, primarily with ground squirrels and prairie dogs.

Larvae. The larva has been described for A. aleutus in Ritcher (1966).

Status of Classification. This genus is the only New World aphodiine which has a dorsal, fleshly lobe attached to the middle of the male paramere. Other genera may have apical processes, but none are lobed. The genus has three recognized species groups (Gordon and Skelley 2007), based on external morphology and biologies.

References:
Gordon, R. D., and P. E. Skelley. 2007. A monograph of the Aphodiini inhabiting the United States and Canada (Coleoptera: Scarabaeidae: Aphodiinae). Memoirs of the American Entomological Institute 79: 580 pp.
Ritcher, P.O. 1966. White grubs and their allies: A study of North American scarabaeoid larvae. Oregon State University Press, Corvallis, Oregon. Studies in Entomology 4: 219 pp.