Sphinx statues may not have been created solely by humans, according to scientists from New York University.

The team, led by Dr Leif Ristroph, studied the giant stone statues to figure out how they may have formed.

Most sphinxes are found in Egypt, including the Great Sphinx of Giza which is around 4,500 years old, 20m high and a huge 73m long.

Previously it was thought that these ancient monuments were carved completely by humans, but now Dr Ristroph and his team believe that might not be the case.

How were the sphinx made?

The new research suggests erosion, by the weather, may be partly responsible for their distinctive shape.

«Our laboratory experiments showed that surprisingly Sphinx-like shapes can, in fact, come from materials being eroded by fast flows» co-author Dr Leif Ristroph said.

As part of the study to understand how ancient Egyptian sphinx statues were formed, the scientists tried to recreate weather conditions from around 4,500 years ago in Egypt in their lab.

This is because they wanted to try to see how wind moved around and shaped the rocks to create unusual rocky formations called yardangs.

The scientists believe that sphinx statues might have started out as one of these unusual-shaped yardangs, and that ancient humans might have used one as a base to carve in details for a sphinx statue.

«There are, in fact, yardangs in existence today that look like seated or lying animals, lending support to our conclusions,» Dr Ristroph said.

What is erosion?

Erosion is the process in which soil or rock is worn down slowly over time by wind or water.

For their experiment the scientists used lumps of soft clay with harder material inside to recreate a similar landscape to north-eastern Egypt.

They then sent a fast-flowing stream of water through a tunnel with the clay in, to try to mimic the strong winds that would have shaped them through erosion over time.

They eventually reached a sphinx-like shape where the harder material in the lump became the «head» of the sphinx, and other features such as a ‘neck’, ‘paws’ and ‘back’ were revealed.

The scientists think that ancient Egyptians might have seen these unusual shaped yardangs and, inspired by their animal-like shapes, decided to carve them into mythical creatures.

Read more at: https://www.bbc.co.uk/newsround/67285692