Making the transition from water to dry land was a huge evolutionary accomplishment. The first creatures to walk on land were ancient animals. Now these types of animals are extinct. Researchers believe they pushed beyond the water edge by using their tails.
Scientists have studies the movements of a unique fish. This fish is called the African mudskipper. Researchers observed that tails were essential in movement Tails could have allowed the predecessors of this type of fish to gain traction on sandy beaches.
Daniel Goldman is a physicist who worked on a study on ancient animals. The team of researchers looked at how animals left seas and started walking on beaches. The study was published in the journal Science.
The study revealed that a number of organisms which exists on Earth today resemble ancient animals of the Devonian era – which ended approximately 360 million years ago.
The African mudskipper is an amphibious fish that lives between two worlds: water and dry land. It tries never to dry out completely. These species is about four inches long with two front legs and a tail. They breathe through their skin and gills. They can be found in mangroves or mudflats.
As these fish climb out of the water, their front legs synchronize reaching up, digging into the sand and thrusting their bodies forward. Scientists revealed that as they modified the slope of the sandy beach, the fish relied on their tails to push them forward and to keep them from sliding.
Researchers 3D printed a robot which had similar characteristics to the fish in the study. It used the same motions to move up slopes as if using a pair of clutches. It was tested in an environment filled with plastic beads, as sand could have damaged it.
The robot, called MuddyBot, has two limbs and a strong tail, and it is powered by electric engines. It recreates ancient animal movements.
Early animals that lived on land did not have control over their limbs, so the tail helped them move around. The first vertebrate animals to emerge from the water had four legs instead of two. In future, scientists will try to find and analyze fossils, and to reveal more pieces of the evolutionary puzzle.