Tibia and Fibula

Dog

Tibia and fibula are not fused; Fibula is as long as the tibia; short prominent tibial crest marked with impression

Ruminant

Fibula is vestigial, no interosseous space; lateral malleolus articulates separately; malleolar bone is present

Horse

Only proximal half of the fibula remains (reduced to the head and shaft only); lateral malleolus of fibula is fused with the tibia

Pig

Tibia and fibula are not fused; Fibula is as long as the tibia; tibial crest is long and distinct

Bird

Tibia fused with dorsal tarsal bone forming tibiotarsus (making it longer than femur); fibula is thin and splint like