The wyverns in my world are similar to the classical depictions of wyverns, specifically in that the two legs are attached directly under the wings' shoulders, rather than the avian form found in modern depictions
To note their other features: They are tripedal, walking on their tail and legs. Their wings are webbed and cannot be used to walk, but are used for flight. Their legs resemble a plantigrade forelimb, with 2 visible segments and a backwards-pointing elbow. The leg's attachment point is at the breast, as in lizards. They have an avian head/neck with reptilian jaws, and would have a long tail like a legless lizard. They are also carnivorous, and roughly horse-sized. They hunt like eagles, and have raptorial feet. Their skin is scaly, and has no fur or feathering
While I could use the same anatomy as in winged quadrupeds, there is also the point that these wyverns only have 4 limbs, like real tetrapodal species. However, there is still the issue that, unlike real tetrapods, the wyvern's limbs are clustered about the chest
Considering this, could normal tetrapodal anatomy (specifically regarding the torso and limb attachments) realistically be altered to form these wyverns