In a nutshell Synovial joints—the flexible, lubricated connections that allow smooth movement in our bodies—first appeared in the common ancestor of all jawed vertebrates but are absent in jawless ...

“Humans and fish aren’t close evolutionary cousins,” Siek said. “We’re part of the same phylum called Chordata. We share a common ancestor. Those in Chordata have backbones. So, this ...

evolved from their fish ancestors. The animal was a so-called lobe-finned fish that lived about 375 million years ago. Named Tiktaalik rosae by its discoverers, it is a classic example of a ...

Ancient fish had synovial joints, challenging the idea that flexible skeletons evolved on land. Fossils and modern fish show ...

For this, we can go to the fossil record. Fish appear in the fossil record before four-legged animals (tetrapods), so the ancestor of this group must be at least as primitive as a fish.

These joints are present in land vertebrates and bony fish, suggesting this feature had evolved in the common ancestors of these groups, but it remains unclear when in early vertebrate evolution ...

More information: Sharma N, et al. Synovial joints were present in the common ancestor of jawed fish but lacking in jawless fish. PLOS Biology (2025). DOI: 10.1371/journal.pbio.3002990 ...