What is the difference between the structure of the spine of the tailed and tailless amphibians?

The skeleton of amphibians consists of 4 sections: caudal, sacral, dorsal and cervical. And if the structure of the cervical and sacral spine is the same, then already in the dorsal spine we notice the first differences. For example, in tailed amphibians there are no real ribs, they are replaced by short upper ribs, like in fish, and the shoulder girdle consists of cartilage. In some species of tailless, we can observe already fully formed ribs.
The next major difference we can observe in the tail section. And if in tailless these vertebrae are reduced and fused into one bone, then in caudates this section is developed, mobile and consists of a large number of vertebrae.