The Collaborative International Dictionary of English v.0.48:

Zygodactylae \Zyg`o*dac"ty*lae\, n. pl. [NL.] (Zool.)
   The zygodactylous birds. In a restricted sense applied to a
   division of birds which includes the barbets, toucans, honey
   guides, and other related birds.
   [1913 Webster]