Giant crocodile-like frog roamed rivers more than 250 million years ago

By Mark Waghorn via SWNS

A giant 6-and-a-half-foot crocodile-like frog roamed rivers more than 250 million years ago, according to new research.

The ancient amphibian was two meters long - and lived before the age of the dinosaurs, scientists said.

It was identified from fossilized remains unearthed in the KwaZulu-Natal Province of South Africa.

They were entombed in rocks that once formed the floor of a tidal flat or lagoon of the prehistoric Karoo Sea.

Study lead author Dr. David Groenewald, of the University of the Witwatersrand in South Africa, said: "The findings are significant because they help to fill in gaps in our knowledge of these ancient animals.

"The remarkable tracks and traces preserved on the Dave Green palaeosurface are a window onto the shoreline of the Karoo Sea roughly 255 million years ago.

"They provide direct evidence of how these animals moved and interacted with their environment."

Named Rhinesuchid temnospondyl, it resembled a cross between a crocodile and a large salamander.

The international team analyzed seven body impressions and a number of tail marks.

Based on the spatial arrangement, the researchers interpret them to have been made by one or two animals swimming from one resting spot to another - perhaps while searching for food.

The extinct predator is known mainly from skeletal remains. The exceptional set of trace fossils shed fresh light on how it moved through its environment.

The sinuous shape of the tail marks suggests it propelled itself with continuous side-to-side tail motions like modern crocodiles and salamanders.

The shape of the body impressions, as well as a relative lack of footprints alongside, suggests it tucked its legs against its body while swimming - like a crocodile.

These fossils indicate an active lifestyle of swimming and bottom-walking, an interpretation made possible by the extraordinary preservation.

The site is a primitive animal graveyard, providing a treasure trove of early four legged tetrapods that lived on land and in water.

There are also the remains of ancient fish and invertebrates - making it a key locality for understanding Permian ecosystems.

Dr. Groenewald added: "In addition to its remarkable scientific contribution, this study also demonstrates how important paleontological discoveries are often made by curious people bringing their findings to the attention of paleontologists."

Rhinesuchid temnospondyl is described in the journal PLOS ONE.