The fibula appears to be in the same condition as in the horse.
But think of gradation, even now manifest, (Tibia and Fibula).
In the bird, the fibula is small and its lower end diminishes to a point.
That is a fibula, Cora, such as I saw in a museum in Norway.
The first (a) is on a fibula from Etruria (fig. 190 of this paper).
The common site of fracture is the lower part of the tibia or fibula.
Rarely, the surcote is made with a "fente" at the throat, and fastened with a fibula.
The development of the fibula in general corresponds to that of the ulna.
The fibula may be well developed or quite vestigial or absent.
The tibia and fibula are always distinct and well developed.