Amazing shots show a 'frog within a frog' which has been impressing scientists.

Cannibalism is in full effect with this frog, which was discovered by Dr Thomas Kleinteich, and has been referred to as the 'meta-frog', referring to the abstract nature of the image.

The main frog was a 70-millimetre long Argentine horned frog preserved in alcohol, whose provenance was unknown.



The interior frog was more than half her length and thought to be a juvenile Lithobates pipiens, although the two aren't common in the same geographical area.

The Argentine horned frog actually has a wide mouth and can eat anything from the usual snacks of insects and worms to lizards, snakes, rodents and even other frogs.

As the images show, the Argentine horned frog swallowed the smaller frog headfirst.



Its head can be seen in the belly, with the left leg running through the oesophagus of the horned frog and its foot lying across her tongue.

Dr Kleinteich was thrilled at the discovery, which he uncovered working as part of the Functional Morphology and Biomechanics working group at the Zoological Institute at Kiel University in Germany.

He took the image using a micro-CT scanner to make 3D images of frog specimens using X-ray computed tomography

The group has been conducting research into the stickiness of amphibian tongues.

He told CNET: "Last year I was able to show experimentally that horned frogs can produce extremely strong adhesive strength with their tongues, which they also need in order to catch larger prey.

"With the micro-CT I am able to show, for the first time, how such a large catch can even fit inside a horned frog."