Key to the Genera of New World Pentodontini
Brett C. Ratcliffe 2014
1. Antenna with 9 segments...........................................................................................2
1´. Antenna with 10 segments.......................................................................................5
2. Metafemora greatly thickened. Meso- and metatibia short, greatly expanded apically.
Color testaceous. Peru, Bolivia; 1 species......................Pentodina Endrödi, 1968
2´. Metafemora not greatly thickened. Meso- and metatibia normal in length, not short;
mesotibia at apex normal, metatibia at apex expanded or not. Color reddish brown or
black........................................................................................................................3
3 (2´.). Head in both sexes with short horn. Apical region of pronotum declivous.
Argentina; 3 species................................................Eremobothynus Ohaus, 1910
3´. Head lacking horns, instead with small tubercle or transverse carina. Apical region of
pronotum not declivous...........................................................................................4
4 (3´). Protibia quadridentate. Ecuador (Galapagos Islands); 4 species.........................
............................................................................Neoryctes Arrow, 1908 (in part)
4´. Protibiae tridentate. SW United States; 1 species........Anoplognatho Rivers, 1889
5 (1´). Small species, generally less than 15 mm in length. Head lacking carina,
tubercles, or horn; Euetheola humilis (Burmeister) and Denhezia caucacola Endrödi
usually with weak frontoclypeal carina. Pronotum lacking tubercle or fovea .........6
5´. Larger species, generally greater than 15 mm in length. Head usually with transverse
carina (on subapex of clypeus or frontoclypeal region), tubercles, or horn (may be
obsolete in some Coscinocephalus specimens). Pronotum either steeply declivous on
anterior half or with tubercles or short horn behind anterior margin (rarely obsolete in
Aceratus females, Aphonus, Indieraligus, Collagenus, some Tomarus, occasionally
Philoscaptus) and usually with subapical fovea or sulcus..................................9
6 (5). Color black.......................................................................................................7
6´. Color testaceous or reddish brown, pronotum usually slightly darker ................8
7 (6). Protibia tridentate, lacking small accessory teeth. Propygidium without stridulatory
striae. Southern United States through South America; 7 species................................
..............................................................................................Euetheola Bates, 1888
7´. Protibia tridentate, with small accesory teeth. Propygidium with stridulatory striae.
African genus with H. arator (Fabricius) introduced into southern Brazil...........
.......................................................................Heteronychus Burmeister, 1847
8 (6´). Pronotum usually with minute, double tubercle at apex. Honduras to Brazil and
Peru; 2 species.......................................................Parapucaya Prell, 1934 (in part)
8´. Pronotum lacking double tubercle at apex. Colombia; 1 species........................
...............................................................Denhezia Dechambre, 2006 (incertae sedis)
9 (5´). Size large (30–35 mm). Color reddish brown (not piceous or tomentose grey).
Mandibles lacking teeth on external margin. Head of male with central horn, female
with tubercle. Pronotum of male with strong, bifurcate tubercle or short horn, female
with pronotum simply convex. Protibia with a small, basal, fourth tooth ..............10
9´. Not with above combination of characters...............................................................11
10 (9). Elytra with deeply punctate striae and punctate intervals. Metatarsomere 1
greatly expanded, subtriangular. Argentina, Brazil, Colombia; 1 species.............
.................................................................................Thronistes Burmeister, 1847
10´. Elytra smooth, lacking deep striae. Metatarsomere 1 cylindrical. Peru; 1 species...
.....................................................Heteroglobus Dupuis and Dechambre, 2006
11 (9´). Clypeal apex acute, unidentate......................................................................12
11´. Clypeal apex bidentate, truncate, or rounded......................................................13
12 (11). Mandibles large, tridentate. Southwestern United States, northern Mexico; 2
species..............................................................................Oxygrylius Casey, 1915
12´. Mandibles smaller, nearly hidden by clypeus, lacking lateral teeth. South
America; 11 species.........................................................Oxyligyrus Arrow, 1908
13 (11´). Transverse carina present immediately behind apex of clypeus...................14
13´. Transverse carina absent immediately behind apex of clypeus............................15
14 (13). Transverse carina (usually tridentate) just behind apex of clypeus. Pronotum
without tubercles. Size generally less than 17 mm. United States west of the
Rocky Mountains; 6 species........................................Aphonus LeConte, 1856
14´. Transverse carina just behind apex of clypeus entire or bidentate. Pronotum
tuberculate or not. Size generally greater than 17 mm. Central and SW United
States to Costa Rica; 28 species...............................Orizabus Fairmaire, 1878
15 (13´). Mandibles only slightly visible from above or hidden under clypeus; outer
edge arcuate, not toothed or convexly rounded...................................................16
15´. Mandibles distinctly visible from above; outer edge toothed or convexly
rounded or lobed..................................................................................................20
16 (15). Clypeus strongly narrowed toward apex, apex narrowly bidentate. Color
castaneous to black. Canada to Chile; 28 species...Tomarus Erichson, 1847 (in part)
16´. Clypeus not strongly narrowed toward apex, apex broadly truncate. Color
fulvous to rufocastaneous....................................................................................17
17 (16´). Apex of metatibia with 7–8 non-articulated, small teeth. Southwestern United
States, northern Mexico; 2 species............................Coscinocephalus Prell, 1936
17´. Apex of metatibia subtruncate, lacking 7–8 non-articulated, small teeth (small,
articulated spurs may be present)......................................................................18
18 (17´). Frontoclypeal suture present, deeply impressed, strongly arcuate either side of
middle. Head lacking horns or tubercles. Length 14 mm or less. Honduras to
Brazil and Peru; 2 species...............................Parapucaya Prell, 1934 (in part)
18´. Frontoclypeal suture absent. Head with horns, tubercles, or low boss. Length
18 mm or greater..............................................................................................19
19 (18´). Head with small horn (males) or tubercle (females) present next to each eye.
Apex of pronotum declivous with subapex weakly to strongly bituberculate. Panama,
Colombia, Ecuador; 3 species...............................................Pucaya Ohaus, 1910
19´. Paired horns or tubercles absent. Center of head with strong, elevated, transverse
carina, carina complete from side to side. Apex of pronotum evenly convex.
Venezuela; 1 species.................................Collagenus Ratcliffe and Hardy, 2005
20 (15´). Mandibles entire or weakly sinuate on lateral edge.....................................21
20´. Mandibles distinctly trilobed or tridentate (1 apical tooth, 2 lateral teeth) or trilobed
..............................................................................................................................29
21 (20). Protibia tridentate...........................................................................................22
21´. Protibia quadridentate............................................................................................23
22 (21). Males with long, recurving head horn and pronotum with bifurcate horn. Color
black to grey-tomentose (males) to piceous (females), opaque. Brazil, Argentina; 1
species...............................................................................Diloboderus Reiche, 1859
22´. Males lacking horns. Color reddish brown, shiny. Cuba; 1 species.....................
...........................................................................................Gorditus Ratcliffe, 2010
23 (21´). Clypeus strongly contracted to apex, apex narrowly bidentate. Ecuador
(Galapagos Islands); 4 species....................................Neoryctes Arrow, 1908 (in part)
23´. Clypeus normally subtriangular, apex truncate, acute, narrowly rounded, or weakly
emarginate............................................................................................................24
24 (23´). Pronotum lacking distinct apical fovea, sulcus, or tubercle........................25
24´. Pronotum with distinct apical fovea, sulcus, or tubercle (may be indistinct in small
specimens of Barutus).........................................................................................27
25 (24). Base of pronotum lacking marginal bead. Meso- and metatibiae in males with
extremely long, dense setae; thoracic sternites with long, sparse setae. Puerto Rico; 1
species........................................................................Indieraligus Dechambre, 1979
25´. Base of pronotum with marginal bead. Meso- and metatibiae without long, dense
setae; thoracic sternites obscured by long, dense setae......................................26
26 (25´). Club of antennae subequal in length to antennomeres 2–7. Paraguay; 1 species
...........................................................................................Heikeianus Endrödi, 1978
26´. Club of antenna large, bulbous, as long as antennomeres 1–7. Peru; 1 species...
...................................................... Piscoperus Ratcliffe and Giraldo, 2014
27 (24´). Frontoclypeal suture strongly elevated into a transverse, bilobed ridge.
Pronotum with shallow, suboval fovea behind subapical tubercle (male) or with
subapical, rounded swelling (female). Mexico; 1 species...Gillaspytes Howden, 1980
27´. Frontoclypeal suture with transverse tubercle only. Pronotum lacking shallow,
suboval fovea behind apical margin, instead with a median, longitudinal sulcus, or a
shallow fovea either side of middle, or with or without faint depression behind
anterior margin ................................................................................................28
28 (27´). Apex of clypeus narrowly rounded, almost parabolic. Pronotum with basal bead
present. Pygidium in males lacking distinctive patch of long, dense, reddish brown
setae either side of midline. Prosternal process long, thick, columnar. Panama, Costa
Rica; 1 species.......................................................................Barutus Ratcliffe, 1981
28´. Apex of clypeus narrowly truncate. Pronotum with basal bead absent. Pygidium in
males with distinctive patch of long, dense, reddish brown setae either side of
midline. Prosternal process small, narrowly subtriangular. Dominican Republic, Haiti;
2 species................................................................Endroedianibe Chalumeau, 1981
29 (20´). Apical segment of maxillary palpus expanded, subtriangular. South America; 6
species............................................................................Hylobothynus Ohaus, 1910
29´. Apical segment of maxillary palpus normal, cylindrical...................................30
30 (29´). Elytra with sparse, minute punctures, appearing smooth............................31
30´. Elytra distinctly punctate or punctate-striate.......................................................32
31 (30). Clypeus at base near antennal insertion distinctly constricted. Prosternal process
long, columnar, apex anvil-shaped with strong spine on posterior edge. Southern
Brazil; 2 species.........................................................................Aceratus Prell, 1936
31´. Clypeus at base near antenna normal, not constricted. Prosternal process also long,
columnar but apex bluntly rounded and lacking spine on posterior edge. Mexico
through South America; 27 species............................Bothynus Hope, 1837 (in part)
32 (30´). Clypeal apex rounded or subtruncate, usually weakly emarginate. Frontoclypeal
carina, if present, short, less than 1/3 width of base of clypeus. Body form suboval,
stout, strongly convex on dorsum. Pronotum coarsely punctate. Argentina, Uruguay,
southern Brazil; 2 species............................................Philoscaptus Bréthes, 1919
32´. Clypeal apex bidentate or quadridentate, if subtruncate then frontoclypeal carina
long or represented by 2 tubercles. Body form usually elongate, less stout, not
strongly convex on dorsum. Pronotum variably punctate..................................33
33. (32´). Propygidium often extended so that pygidium is foreshortened; surface with
distinct, transverse, stridulatory bands. Mexico through South America; 27 species...
.....................................................................................Bothynus Hope, 1837 (in part)
33´. Propygidium normal in length so that pygidium not foreshortened; surface granulate
or not but lacking transverse stridulatory bands. Canada to Chile; 28 species.......
.........................................................................Tomarus Erichson, 1847 (in part)