Simple Key

0a. Middle and hind tarsi with claws ... Bolbites Harold, 1868
0b. Middle and hind tarsi lacking claws ... 1

1a. (0b) Middle and hind tarsi with fewer than five segments ... 2
1b. Middle and hind tarsi with five segments ... 5

2a. (1a) Middle and hind tarsi four-segmented. Brazil, Venezuela ... Tetramereia Klages, 1907
2b. Middle and hind tarsi two- or three-segmented ... Dendropaemon Perty, 1830 ... 3

3a. (2b) Hind tarsi two-segmented; basal segment cylindrical, almost as long as tibia; apical segment small, inconspicuous; body strongly convex. Brazil ... Dendropaemon (Paradendropaemon) Edmonds, 1972
3b. Hind tarsi two- or three segmented; if two-segmented, basal segment flattened and much shorter than tibia; body dorso-ventrally flattened ... 4

4a. (3b) Propleuron (hypomeron) with carina extending from coxa toward lateral margin. Upper portion of eyes small (except D. denticolle Felsche). Middle and hind tarsi two- or three-segmented. South America except Chile ...Dendropaemon (Dendropaemon) Perty, 1830
4b. Propleuron (hypomeron) smooth, lacking carina. Upper portion of eyes large, rounded. Middle and hind tarsi three-segmented, apical segment very small. South America except Chile ... Dendropaemon (Coprophanaeoides) Edmonds, 1972

5a. (1b) Basal segment of middle and hind tarsi expanded, wider than long or nearly so ... 6
5b. Basal segment of middle and hind tarsi elongate, always much longer than wide ... 7

6a. (5a) Dorsal surfaces of hind tibia and first four tarsal segments covered by coarse, setigerous granules. Labial palpi 3-segmented. Dorsum unicolored. Brazil ... Homalotarsus Janssens, 1932
6b. Dorsal surfaces of hind tibia and tarsus not granulate. Labial palpi one- segmented. Dorsum bicolored. Ecuador ... Megatharsis Waterhouse, 1891

7a. (5b) Basal antennal lamella enlarged, strongly concave apically, receiving two apical lamellae. Metepisternum with posterior tab overlapping edge of elytron ... 9
7b. Basal antennal lamella not enlarged, not hollowed to receive apical two lamellae. Metepisternum simple, lacking tab ... 8

8a. (7b) Pygidium not margined basally. Female with four-segmented front tarsi (lacking in male). Metasternum simply acuminate anteriorly in both sexes. Front legs of male not greatly elongate, tip of femur not extending beyond lateral margin of prothorax; hind femur of male not modified. Outer margins of elytra (seen from above) curving outward. Venezuela, Colombia, Brazil, Bolivia, Peru, Argentina, Paraguay, Uruguay ... Gromphas Brullé, 1834
8b.Pygidium margined basally. Front tarsi lacking in both sexes. Metasternum simply acuminate anteriorly in female; in male, strongly produced, lobate anteriorly. Front legs of male elongate, tip of femur extending well beyond lateral margin of prothorax. Anterior margin of hind femur of male interrupted by spinose concavity. Outer margins of elytra (seen from above) parallel. Colombia, Ecuador, Peru, Bolivia, Argentina ... Oruscatus Bates, 1870

9a. (7a) Clypeal margin deeply, acutely emarginate medially, emarginations producing two acute teeth that are separated from adjacent clypeal border by external emerginations ... Coprophanaeus Olsoufieff, 1924 ... 10
9b Clypeal margin lacking deep, acute emarginations; at most with two conspicuous median teeth ... 12

10a. (9a) Very large beetles to 50 mm long, length rarely less than 25 mm. Front tarsi present in female; interstriae strongly sculptured (transverse carinae or foveae). South America except Chile ... Coprophanaeus (Megaphanaeus) Olsoufieff, 1924
10b. Small to medium-sized beetles, length rarely over 25 mm. Front tarsi absent in females; interstriae without strong sculpture ... 11

11a. (10b) Male cephalic process variable, usually laminate, never a simple, tapering cylindrical horn (or if so, body completely black). Head surface along outer edge of eye never carinate. Dorsum usually mostly black, rarely conspicuously metallic. Mexico (and extreme southern USA) to Argentina ... Coprophanaeus (Coprophanaeus) Olsoufieff, 1924
11b. Male cephalic process a simple, tapering horn. Head with carina paralleling outer edge of eye. Dorsum usually metallic, never completely black. Brazil, Argentina, Bolivia, Paraguay ... Coprophanaeus (Metallophanaeus) Olsoufieff, 1924

12a. (9b) Head with transverse clypeal carina (in addition to carina or pair of horns separating clypeus and frons). South America except Chile and Ecuador ... Diabroctis Gistl, 1857
12b. Head lacking transverse clypeal carina ... 13

13a. (12b) Metasternum with long, dorsally curved, acute spiniform process extending between apices of front coxae. Posteromedian angle of pronotum prolonged between bases of elytra. ... Oxysternon Castelnau, 1840 ... 14
13b. Metasternum simply angulate anteromedially, never spinose ... 15

14a. (13a) Clypeal process reduced to small tubercle. Lateral clypeal carinae absent. Small species, length rarely exceeding 10 mm. South America except Chile, Argentina, Uruguay ... Oxysternon (Mioxysternon) Edmonds, 1972
14b. Clypeal process spiniform or transverse ridge. Lateral clypeal carinae present. Larger species, length seldom less than 12 mm.Panama, South America except Chile, Uruguay ... Oxysternon (Oxysternon) Castelnau, 1840
 
15a. (13b) Anterior portion of circumnotal carina entire, not interrupted behind each eye. Mexico to Argentina, Jamaica ... Sulcophanaeus Olsoufieff, 1924
15b. Anterior portion of circumnotal ridge interrupted behind each eye ... Phanaeus MacLeay, 1819 ... 16

16a. (15b) Pronotum coarsely granulorugose, at least anterolaterally; puncturing, if present, confined to disk. United States to northwest South America ... Phanaeus (Phanaeus) Macleay, 1819
16b. Pronotum smooth, sometimes weakly punctured; coarse granulation, if present, usually confined to disk of male; if coarse sculpturing present anterolaterally, mixed with some puncturing. Mexico to Argentina ... Phanaeus (Notiophanaeus) Edmonds, 1994