Long ago, 375 million years to be exact, there swam a small fish swam in a large body of water. This was no ordinary fish, even by the standards of 375 million years ago. This fish had rudimentary wrists.
Now, you may be thinking to yourself, what is so special about a fish with a wrist? Understandable considering that most people, myself included, are not experts on fish anatomy. The bones in a fish’s fin do not make up a wrist. What makes this discovery so important? This fish, the Tiktaalik is currently the biggest link between oceanic life and the first animals to walk on land.
Tiktaalik had a flat head similar to alligators as well as a neck. Fish have a more rounded head and do not have a neck because their vertebrae connect their heads and their spines. This anatomical difference was probably the first tip off to archaeologists that this was no ordinary fossil. They were even more excited when they analyzed it further in the laboratory. There they discovered the rudimentary wrist. Having a wrist allowed this fish to be able to push off of surfaces, most likely near the bottom of a shallow area of water. In other words, this fish had the ability to crawl. Although this fish had no lungs, it was still possibly capable of crawling above water, even if it couldn’t survive up there yet. This fish is almost certainly an ancestor of the first beings to crawl out of the water.