The syrinx is the vocal organ of the birds and it corresponds to a modification of the apparatus respiratorius, being at most of the cases, localized at the caudal end of the trachea and the cranial portion of the bronchi. The main purpose of this paper is to describe the syrinx anatomy of the Dendrocolaptidae, with the analysis of 11 from the 13 genera accepted to this family. Besides the two series of cartilaginous elements (“A” and “B”) previously recognized, we adopted a third series of elements designated as “T” elements, which correspond to those cranial to the Membrana tracheosyringealis. The structural variation of the Dendrocolaptidae syrinx is considered small when compared with other well known suboscine taxa, such as the Pipridae. We found out intra-group diagnostic characters, as well as some phylogenetically informative characters. Contrary to the current knowledge, the woodcreeper’s syrinx is dorsoventrally assimetric, a characteristic that should be taken into account in future studies of other suboscine groups, especially in the case of using syringeal anatomy for systematic studies.
