Acanthoceridae Lacordaire, 1856 (synonym).

Type genus Ceratocanthus White, 1842 (= Acanthocerus MacLeay, 1819 not Acanthocerus Palisot de Beauvois, 1818).

Description. Length 2.0-10.0 mm. Shape variable, generally globose or nearly spherical when head and pronotum deflexed. Color black, greenish black, or purplish, often with metallic luster. Head deflexed. Antennae 8, 9 or 10-segmented, with 3-segmented, opposable club; club oval or elongate, first segment not cupuliform. Eye canthus developed. Eyes developed. Labrum partially exposed beyond apex of clypeus, prominent. Mandibles partially exposed beyond apex of clypeus. Maxillae with 4-segmented palpi, labium with apex not indented, with 4-segmented palpi. Pronotum generally convex, smooth or punctate; base sinuous or rounded or (rarely) other shape. Scutellum exposed, triangular. Elytra convex, generally punctate, striae well-defined or not. Pygidium concealed by elytra (not in Scarabatermitini). Hind wings well-developed or reduced, with M-Cu loop absent, MP3 and MP4 veins present or absent. Venter with surface generally smooth, sometimes vermiculate. Prosternum bi-concave. Mesosternum not invaginated. Abdomen with 5 free sternites and 8 functional spiracles; spiracles 1-7 situated on pleural membrane, spiracle 8 situated in tergite. Protibiae with 2 or 3 teeth. Meso- and metatibiae without transverse carinae. Metatibia generally expanded at the apex. Tarsi 5-5-5. Ventral position of protarsi basad to the second tibial tooth. Tarsal claws simple. Male genitalia symmetrical.

Composition. The subfamily Ceratocanthinae includes three tribes, 40 genera, and 328 species.

Distribution. Australian, Afrotropical, Indomalaysian, Neotropical, Nearctic, and Palaearctic regions.

Natural history. Adults can be collected on the bark and branches of dead trees and on fungi. Adults have also been found in association with termites and ants and adults are occasionally attracted to lights. Most species are able to deflex their head and pronotum, thus forming a ball. This behavior probably helps them to avoid predators. Adults probably feed on fungi or rooting wood. Larvae have been collected under bark and in burrows of Passalidae (Coleoptera: Scarabaeoidea) (Jameson 2002). Adults and larvae of some species stridulate.

Bibliography
Jameson, M. L. and B. C. Ratcliffe. 2002. Chapter 29. Series Scarabaeiformia Crowson 1960, Superfamily Scarabaeoidea Latreille 1802, The Scarabaeoid Beetles pp. 1-5. In, Arnett R. H. and M. Thomas (editors). American Beetles: A Handbook of the Beetles of Nearctic America. CRC Press, Boca Raton. FL.

Ocampo, F. C. 2006. Phylogenetic Analysis of the Scarab Family Hybosoridae and Monographic Revision of the New World Subfamily Anaidinae (Coleoptera: Scarabaeidae). Bulletin of the University of Nebraska State Museum, Vol. 19. 210pp.