(syn. Ptilopachus Ϯ Nahan's Forest Partridge P. nahani) Gr. ακεντρος akentros  spur-less  < negative prefix α- a- ; κεντρον kentron  spur  < κεντεω kenteō  to prick; ορτυξ ortux, ορτυγος ortugos  quail; "One feature, however, in which virtually all the species of Francolinus and Pternistis agree - so far as I am aware - is the presence, normally, of one or two metatarsal spurs in adult males. Nevertheless, in Francolinus nahani Dubois such spurs are never to be seen, nor is there even a modified scale at the point where they usually arise.  ...  In other respects this Partridge does not depart widely from the genus Francolinus. The bill is not quite so weak as in F. lathami, and the rectrices number fourteen, as usual in Francolinus. The only additional feature of note is the bareness of the skin around the eye. But the complete absence of spurs alone may be regarded as of generic importance, and I propose the new genus Acentrortyx, with Francolinus nahani Dubois as its type species." (Chapin 1926). This aberrant African partridge, formerly known as Nahan's Francolin and treated in Francolinus in Phasianidae, probably merits generic separation. 

Search for more names on the Key to Scientific Names in Ornithology by James A. Jobling.
Recommended citation
Jobling, J. A. (2018). Key to Scientific Names in Ornithology. In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2018). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 9 December 2018).