Introduction to Pterosaur and Bird Wing Structures

Pterosaur and bird wing structures are very interesting and obviously related.
We can see that in the development from pterosaur to modern bird that the pterosaur fifth finger (which is often incorrectly labeled as the fourth finger) was shortened and some fingers (digits) were fused.
This is a large topic which I will discuss in the next few posts.
For now, just notice the pterosaur thumb metacarpal sticking out. It is not numbered in the picture and is a little hard to see but it is shown. In standard evolution terminology this is called the "pteroid bone".