In many birds the spaces between the metasternum and the posterior processes and again the spaces between this and the oblique process are filled up by proceeding ossification and either remain as notches, or as fenestrae, or they are completely abolished so that the breastbone is turned into one solid more or less oblong plate.
In conformity with these reductions the breastbone of the moas is devoid of any coracoidal facets; there is no trace of a keel, and the number of sternal ribs is reduced to three or even two pairs.
The trunk is relatively small, with few slender ribs and a keeled breastbone (sternum).
A muscular body should have a level back and a deep broad chest with a prominent breastbone.
When you have your surgery, it is necessary for the surgeon to cut the breastbone ( sternum ) to get to the heart.
How would you define breastbone? Add your definition here.