- Systematic revision of the genus Coelotrachelus Schmidt, 1913 (Scarabaeoidea: Scarabaeidae: Aphodiinae) (2009)
- The species belonging to the genus Coelotrachelus Schmidt, 1913 are redescribed and figured. The Mexican Coelotrachelus ixtapalapaensis, new species, is described.
- Gordonius rhinocerillus, a new genus and species of Colombian Aphodiini (Coleoptera: Scarabaeidae: Aphodiinae) (2009)
- Gordonius rhinocerillus, a new genus and new species of Colombian Aphodiini is described and figured. It is the only known member of New World Aphodiinae where the male has a prominent horn on the head.