1	Distributed in the Old World	2
–	Distributed in the New World	9
2	Labrum concealed by clypeus. Only known from the Indo-Malayan region	Helopeltarium (Figs 1H, 37I, 38)
–	Labrum not concealed by clypeus	3
3	Elytra with distinctly impressed sutural striae (Fig. 1V)	Crephelochares (Figs 1V, 11G, 27B–D, 28)
–	Elytra without sutural striae	4
4	Labrum with apical region anteriorly flattened, thus bearing a fine transverse carina across anterior margin (Fig. 11D, E); pronotum antero-laterally explanate and bent upwards (marginal areas concave; Fig. 23A, B); elytra with margins explanate, especially along anterior third (Fig. 23A); body smaller than 5 mm; basal piece of aedeagus nearly 1.5 × longer than parameres (Fig. 22D). Only known from the Afrotropical region	Batochares (Figs 1I, 22D, 23)
–	Labrum with apical region not anteriorly flattened, with even surface (without transverse carina, e.g., Fig. 11H, K); pronotum evenly convex, not laterally explanate (e.g., Fig. 1A, G); elytra with margins not explanate, at most flared (e.g., Fig. 1A, G); if elytra with margins explanate, body approximately 10 mm (e.g., Fig. 1C); basal piece of aedeagus variable in length, usually less than 0.5 × length of parameres (e.g., Fig. 16C–F). Afrotropical or elsewhere in the Old World	5
5	Head and pronotum with granulate surface (Fig. 17); body size small (ca. 3 mm); prosternum with median carina; elytra narrowly explanate laterally, with ten well defined rows of coarse serial punctures impressed into striae (Fig. 17A). Only known from the Afrotropical region	Acidocerus (Fig. 17)
–	Head and pronotum shallowly to moderately punctate, without granulations (e.g., Fig. 1A, E, F); body size variable (2–14 mm); prosternum flat to medially broadly bulging, without median carina; elytra at most flared, with or without impressed serial punctures (e.g., Fig. 1A, E, F). Afrotropical or elsewhere in the Old World	6
6	Body length 8.5–14.0 mm; body shape broadly oval in dorsal view, strongly and uniformly convex in lateral view (Fig. 1A); ground punctation extremely fine and shallow; coloration uniformly dark brown (nearly black). Only known from the Afrotropical region	Colossochares gen. nov. (Figs 26, 27A)
–	Body length 1.4–14.0 mm; body shape broadly oval in dorsal view, weakly to moderately convex in lateral view (Fig. 1B, C, E, F); ground punctation from fine and shallow to moderately marked; coloration variable, ranging from yellow to dark brown. Widespread in the Old World	7
7	Body length 1.4–4.8 mm; inner margin of maxillary palpomere 2 straight to nearly straight (Fig. 12G); metaventrite with posteromedian glabrous patch (e.g., Figs 18C, F, I); posterolateral glabrous patches absent; antennae with eight or nine antennomeres	Agraphydrus (Figs 1M, S, T, 18–20)
–	Body length 2–10 mm; inner margin of maxillary palpomere 2 weakly and evenly curved (e.g., Fig. 12H, I), seldom nearly straight; metaventrite without posteromedian glabrous patch (e.g., Figs 35C, F, 36C, F); posterolateral glabrous patches may be present; antennae with nine antennomeres (Fig. 12D)	8
8	Body length 2–7 mm; dorsal coloration yellow to medium brown (Figs 35, 36); posterior elevation of mesoventrite flat to simply bulging; tibial grooves absent to weakly developed; aedeagus tubular (Figs 16E, F, 37A–H)	Helochares (in part; Figs 1E, F, 35–37)
–	Body length 6–14 mm; dorsal coloration dark brown to black (Fig. 44); posterior elevation of mesoventrite longitudinally elevated; tibial grooves sharply marked; aedeagus spiked (Fig. 16C, D)	Peltochares (Figs 1B, C, 44, 45)
9	Eyes absent. Known only from a cave in Ecuador	Troglochares (Fig. 56)
–	Eyes present	10
10	Eyes completely divided into dorsal and ventral sections by a lateral projection of frons (Fig. 11C). Size small (<3 mm). Ranging from Costa Rica to northern South America	Quadriops (Figs 1P, 48, 49A–D)
–	Eyes not divided into dorsal and ventral sections by frons (e.g., Fig. 11A, B). Size variable. Anywhere in the New World	11
11	Labrum concealed by clypeus (Fig. 11L), elytral margins broadly explanate (Fig. 33A, D–F). Body extremely dorsoventrally compressed (Fig. 33B)	Helobata (Figs 1J, 11L, 33, 34)
–	Labrum not concealed by clypeus (e.g., Fig. 11H, J), elytral margins not or at most weakly explanate (e.g., Fig. 1N–R). Body form variable but rarely dorsoventrally compressed (e.g., Fig. 1N–R)	12
12	Elytra with distinctly impressed sutural striae (e.g., Fig. 1R). Only Neotropical region	13
–	Elytra without sutural striae (e.g., Figs 1N–Q, U). Both Neotropical and Nearctic	14
13	Posterior elevation of the mesoventrite either flat, broadly elevated or with a longitudinal elevation. Gonopore present and distinct (Fig. 24)	Chasmogenus (Figs 24, 25)
–	Posterior elevation of the mesoventrite with a transverse curved ridge, either sharp or reduced, or with a sharp, pyramidal (triangular) spine-like projection. Gonopore absent (Fig. 47)	Primocerus (Figs 1R, 46, 47)
14	Prosternum with strongly elevated median carina (Fig. 29C)	Crucisternum (Figs 29, 30A–E)
–	Prosternum not or only very slightly carinate or at most tectiform medially (e.g., Fig. 14 A, B)	15
15	Posterior elevation of mesoventrite with a large, sharp and strongly elevated laminar longitudinal carina (Fig. 51C); body in lateral view evenly and moderately convex (Fig. 51B)	Sindolus (Figs 49E–F, 51)
–	Posterior elevation of mesoventrite variable, but never with a large, sharp and strongly elevated laminar longitudinal carina; body in lateral view variable (Fig. 1L, N, O)	16
16	Elytral systematic punctures very distinct, distinctly larger than surrounding ground punctation, forming five longitudinal rows along each elytron (Figs 31, 39). Antennae with nine antennomeres (Fig. 12D)	17
–	Elytral systematic punctures indistinct, usually blending with surrounding ground punctation (e.g., Figs 32, 41, 52). Antennae with eight or nine antennomeres (Fig. 12E)	18
17	Metafemora mostly glabrous, with only few scattered setae on anterior surface (Fig. 31C, F). Found in the highlands of eastern Brazil	Ephydrolithus (Figs 30F–I, 31)
–	Metafemora at most glabrous along apical third (Fig. 39C, F). Recorded from the Andean region	Katasophistes (Figs 39, 40A–D)
18	Antennae with eight antennomeres (Fig. 12E). Size small (< 3 mm)	19
–	Antennae with nine antennomeres (Fig. 12D). Size variable but usually > 4 mm	21
19	Anterior surfaces of metafemora mostly glabrous, with scattered setae (e.g., Fig. 52C, F)	Tobochares (Figs 1N, O, 52–55)
–	Anterior surfaces of metafemora densely covered by hydrofuge pubescence along basal 3/4 (e.g., Figs 32C, 41C, F)	20
20	Body form circular, rounded (Fig. 32A). Size very small (1.9–2.3 mm)	Globulosis (Figs 30J, 32)
–	Body form ovoid, parallel sided (Fig. 41A, D). Size exceedingly small (1.1–1.5 mm)	Nanosaphes (Figs 1L, 40E–H, 41)
21	Fifth ventrite entire, without apical emargination or truncation. Maxillary palps shorter than the width of the head	Radicitus (Figs 1K, 49G–L, 50)
–	Fifth ventrite with apical emargination. Maxillary palps as long or longer than the width of the head	22
22	Head subquadrate (Fig. 11J); eyes relatively small, separated by a distance nearly 6.5 × the maximum width of an eye; mentum and submentum roughly punctate; pubescence covering abdominal ventrites composed of long golden setae; ventral surface of metatarsomeres 1–4 densely setose. Northern Amazon region	Aulonochares (Figs 1D, 21, 22A–C)
–	Head trapezoid; eyes moderate in size, separated by a distance nearly 4 × the maximum width of an eye; mentum obliquely striate, submentum smooth to shallowly punctate; pubescence covering abdominal ventrites composed of short setae; ventral surface of metatarsomeres 1–4 only with paired rows of denticles	23
23	Body size 4.2–7.0 mm; maxillary palps nearly as long as maximum width of the head; internal structural reticulations usually visible along entire dorsal surface of elytra (Fig. 36A, B); metaventrite uniformly covered by hydrofuge pubescence (Fig. 36C); tibial grooves absent to weakly developed; aedeagus tubular (e.g., Fig. 37G). Ranging from USA to Venezuela and Peru (Andean region)	Helochares (in part; Figs 36A–C, 37G)
–	Body size 4.5–9.0 mm; maxillary palps 1.1–1.5 × the maximum width of the head; internal structural reticulations of elytra absent (Fig. 42); metaventrite with median glabrous patch, sometimes very narrow and extending along entire length of metaventrite (Fig. 42C, F); tibial grooves well-developed, with sharp margins; aedeagus divided (e.g., Fig. 16G, H)	Novochares gen. nov. (Figs 1G, 42, 43)