In obsolete|lang=en terms the difference between oryctology and oryctologist
is that oryctology is (obsolete) mineralogy and geology while oryctologist is (obsolete) one versed in oryctology.
As nouns the difference between oryctology and oryctologist
is that oryctology is (obsolete) paleontology while oryctologist is (obsolete) one versed in oryctology.