Some articles on air sac, clavicular air sac:
... The syrinx depends on the air sac system in birds to function specifically, it requires the presence of a clavicular air sac near the wishbone or collar bone ... This air sac leaves distinctive marks or opening on the bones, including a distinct opening in the upper arm bone (humerus) ... While extensive air sac systems are a unique characteristic of saurischian dinosaurs, the clavicular air sac necessary to vocalize does not appear in the fossil record until the enantiornithines (one ...
Famous quotes containing the word air:
“As in hoary winters night stood shivering in the snow,
Surprised I was with sudden heat which made my heart to glow;
And lifting up a fearful eye to view what fire was near,
A pretty Babe all burning bright did in the air appear;”
—Robert Southwell (1561?1595)