Previous thread on the subject.
There’s a bit of confusion here. Turkeys and chickens do have similar leg anatomy. Both have a thin pointed fibula bone that parallels the tibia. Both have tendons that connect the leg muscles to the bone. The difference is that the tendons in the turkey leg are calcified and have become bonelike, while those in the chicken remain fibrous. Turkey tendons are mineralized because turkeys are larger and heavier than chickens so the connections to the muscles need to be stronger.