Source : Webster's Revised Unabridged Dictionary (1913)

Paleornithology \Pa`le*or`ni*thol"o*gy\, n. [Paleo- +
   ornithology.]
   The branch of paleontology which treats of fossil birds.

Source : WordNet®

paleornithology
     n : the paleobiology of birds [syn: {palaeornithology}]