Byrrhidium

Deschodt, Christian M., Davis, Adrian L. V. & Scholtz, Clarke H., 2016, A new monotypic genus, a species synonymy and nomenclatural corrections in the arid-adapted Canthonini (Scarabaeidae, Scarabaeinae) from the Succulent Karoo Biome of south-western Africa, Zootaxa 4147 (4), pp. 490-500 : 497-498

Key to the genera and species in the Byrrhidium group

Note: Some species can only reliably be separated by examination of the male genitalia. The females and fragmented body parts may thus not be identifiable. In those cases, identity may be obtained from geographical distribution, which is included in the key, and may suggest an identity.

1 Fore tibia with three external denticles................................................................... 2

- Fore tibia with two external denticles..................................................................... 6

2 Habitus fairly elongate; Erongo Mountain........................ Versicorpus erongoense Deschodt, Davis and Scholtz

- Habitus convex........................................................ Namakwanus Scholtz and Howden ... 3

3 Clypeal horns as long as, or longer than, distance between them; Windhoek and Gobabeb..... N. irishi Scholtz and Howden

- Clypeal horns shorter than distance between them............................................................ 4

4 Apices of aedeagus not curving outwards terminally, with rows of long setae; Remhoogte Mountains to the south of the Tsondab River canyon...................................................................... N. streyi Frolov

- Apices of aedeagus curving outwards terminally, without rows of long setae...................................... 5

5 Tips of parameres with two notches in frontal view; Naukluft Mountains to the south of the Tsondab River canyon........................................................................... N. endroedyi Deschodt, Davis and Scholtz

- Tips of parameres without notches in frontal view; Hardap Dam........................ N. davisi Deschodt and Scholtz

6 Clypeus clearly bidentate with clypeal horns long.............................. Dicranocara Frolov and Scholtz … 7

- Clypeus quadridentate, with short medial clypeal horns....................................................... 9

7 Aedeagus with lateral clypeal horns on parameres that extend forward; punctures on pronotum fewer, faint and shallow; Rich- tersveld south of Orange River , in South Africa................................... D. tatasensis Deschodt and Scholtz

- Aedeagus without lateral clypeal horns on parameres; punctures on pronotum numerous and obvious; Richtersveld north of Orange River , in Namibia.............................................................................. 8

8 Apex of parameres bulky; northern Richtersveld and Fish River Canyon............. D. inexpectata Deschodt and Scholtz

- Apex of parameres slender; southern Richtersveld: Boom River........................ D. deschodti Frolov and Scholtz

9 Clypeal horns short, mesometasternal suture not well defined; south of Orange River Byrrhidium Harold. ............. 10

- Clypeal horns medium length, mesometasternal suture well defined; north of Orange River..... .. Drogo stalsi gen. et. sp. n.

10 Aedeagus with side protrusions, fore tibia with outer teeth parallel; Richtersveld in South Africa................................................................................................. B. convexum Scholtz and Howden

- Aedeagus plain with no side protrusions, fore tibia with outer teeth diverging; Namaqualand.............. B. ovale Harold