The evolution of hip bones was faster than what was once thought for earth's life forms.

Much of the history dating back millions of years is a mystery but scientists continue to learn more.

One of evolution’s clutch moments, when fish developed weight-bearing hips, leading to tetrapods walking out of the ocean, wasn’t as long-in-the-making a process as previously believed.

According to a group of researchers, the transformation may have taken place in a few evolutionary steps.

They came to this conclusion after studying some of humans’ closest fish relatives and found that hip structure differences weren’t as great as they seemed.

The scientists also found that our fish ancestors already had most of the key structural elements needed for the hip transformation.

The fish used in the study were the Australian lung fish and the Mexican Walking Fish. The lung fish showed evidence of already having the muscles that would have evolved within tetrapods, or four legged animals.

All life forms on Earth lived in the water for hundreds of million of years before developing the strength to move to dry land. It’s also believed they couldn’t endure the sun’s rays as there was no ozone layer at one time to protect life forms from radiation.