Source : Webster's Revised Unabridged Dictionary (1913)

Taxonomist \Tax*on"o*mist\ (t[a^]ks*[o^]n"[-o]*m[i^]st), n.
   One skilled in taxonomy.

Source : WordNet®

taxonomist
     n : a biologist who specializes in the classification of
         organisms into groups on the basis of their structure and
         origin and behavior [syn: {taxonomer}, {systematist}]