The Skeletal Kinematics of Lung Ventilation in Three Basal Bird Taxa (Emu, Tinamou, and Guinea Fowl).

The article presents data from the cineradiographic investigation of the in vivo visceral and skeletal kinematics of lung ventilation in two palaeognaths, the emu, Dromaius novaehollandiae and the Chilean tinamou, Nothoprocta perdicaria, and the neognathous helmeted guinea fowl, Numida meleagris. The study found out that the sternal movement is elliptical rather than linear and scissor-like. The distal ends of the sternal ribs moved dorsally, rather than ventrally, upon inspiration in conjunction to its outward-forward displacement. Moreover, the angular changes at the coracosternal joint can enhance sternal movement, while furcular bending might be an auxiliary mechanism by which the clavicular air sac is compressed and expanded.