Chalcocopris Burmeister, 1846

Copris (Chalcocopris): Burmeister, 1846 (un-paginated) (original description); Erichson, 1847: 108 (syn. of Pinotus); Lacordaire, 1856: 97 (syn. of Copris)

Chalcocopris, Harold, 1869a: 124 (as genus); Chalcocopris, Harold in Gemminger & Harold, 1869b: 1008; Gillet, 1911: 63; Luederwaldt, 1929: 612; Luederwaldt, 1931: 367; Paulian, 1938: 233; Pessôa & Lane, 1941: 437, 465; Blackwelder, 1944: 208; Lange, 1947: 313 (as Calcocopris); Pereira, 1954: 57; Martínez, 1959: 93; Pereira & Martínez, 1960: 49; Halffter & Matthews, 1966: 17, 257; Halffter & Edmonds, 1982: 137; Vaz-de-Mello, 2000: 186; Vaz-de-Mello et al. 2011: 4, 13, 20, 28, 35, 43, 44.

Body shiny black or brownish to emerald green and dull, legs and ventral side black-brownish to cupreous-purplish with metallic reflections, clypeus either evenly coloured or darker on the anterior region. Antennae with eight segments (Fig. 7), clypeal margin evenly curved to slightly sinuate in the middle, with two feeble and rounded teeth, margin either weakly reflexed or completely flat. Margins of both genae and clypeus evenly curved or genae slightly wider, distinctly notched in proximity of the clypeo-genal junction and anteriorly elongated with a blunt tooth. Genal suture slightly to distinctly marked, fronto-clypeal suture either with two small tubercles hump-like and a central conical horn or lacking ornaments. Pronotum without anterior protuberances, posterior margin not bordered, lateral margins well curved and almost obtusely angulated at middle to nearly parallel and straight, anterior margin with a smooth and thin bead slightly elevated over the pronotal surface, anterior angles with inner side either straight and weakly sinuated or outwardly curved, external sides obliquely straight to evenly curved, pronotal punctuation fine and equally distributed. Elytral striae with shallow punctures, deeper at the base and with shallow punctures separated by about three diameters, seventh stria larger, interstriae almost flat to much more convex, eighth interstria clearly swollen. Pygidium either completely bordered or without border at the apex, surface with fine and scattered punctures or with a deeper and homogeneous punctuation. Aedeagus with phallobase either short and strong or slender and thinner, parameres distinctly narrower or much wider and rounded at the apex, dorso-internal margins slightly to strongly concave.

Males and females are distinguished externally by clypeus (somewhat shorter in males) and last abdominal ventrite (medially constricted in males).

Chalcocopris is undoubtedly related to Dichotomius, Isocopris and Holocephalus, with which it shares the lack of external meso- and metatibial transverse carinae, and a coniform to bifurcate ventral clypeal process (Vazde-Mello et al., 2011). It can be distinguished by the combination of eight-segmented antennae (shared only with Isocopris), the pronotal posterior margin unbordered and seventh elytral interstriae very convex at least in apical half (both unique).

Species can be distinguished as follows:

1. Body completely dark brown to black, bright and silky. Clypeus widely and evenly curved, external margin of genae distinctly notched in proximity to the clypeal junction, making anterior part of the genae with an anterad tooth-like projection, frontoclypeal suture either with two small and rounded protuberances at middle or a simple protuberance. Lateral margins of pronotum almost parallel. Pygidium entirely bordered. Central Cerrado of Brazil and Paraguay ...................................................................................................... Chalcocopris inexpectatus sp.nov.

- Head, pronotum and elytra, dorsally, emerald green (in all but two known specimens), red (in only one known specimen) or black with some metallic tinge (in only one known specimen); Ventral side red in all but one (black) specimen, dull to bright above, shiny metallic below. Clypeus slightly sinuated at middle, with two feeble and blunt teeth, anterior external margin of genae lacking notch or any prolongation. Fronto-clypeal suture with a small tubercle either side and a central conical horn. Lateral margins of pronotum distinctly curved to almost angulate at middle. Pygidium apically without border (Fig. 8). Atlantic forest of South and Eastern Brazil and neighboring Paraguay and Argentina (Misiones)............ Chalcocopris hesperus