Lambertz, Bertozzo, and Sander, 2018, Bone histological correlates for air sacs and their implications for understanding the origin of the dinosaurian respiratory system: Biology Letters, v. 14, 20170514
What’s it about?
Modern birds are known for having a system of air sacs throughout their bones, allowing birds to circulate air through their bodies in one direction (rather than air simply going in and out of the lungs as breathing works in mammals). This unidirectional flow of air allows birds to maximize the amount of oxygen extracted from the air they breathe.
In birds, the air sacs are openings in bones that are all connected to the lungs. There are air sacs in vertebrae and wing bones among other places. Many other animals have hollow places in bones that are not associated with air sacs. These openings served to lighten the weight of the bones.
The authors show that there are structures in the bone surrounding the open spaces that distinguish air sacs from other openings.
Why does it matter?
It is known that dinosaurs possessed air sacs. To be able to distinguish air sacs from other openings in bones will permit scientists to discover when air sacs first developed in dinosaurs.
Why did I read this?
This is an interesting topic relating to the origins of dinosaurs and of birds. This paper could easily become incorporated into my class this semester.