London: Researchers have found a "missing link" from a 180 million-year-old fossil that sheds light on how some ancient crocodiles evolved into dolphin-like animals.
The fossil named Magyarosuchus fitosi in honour of the amateur collector who discovered it, Attila Fitos, was unearthed on a mountain range in north-west Hungary in 1996 and stored in a museum in Budapest.
The species featuring a large portion of backbone is nearly five metres long and had large, pointed teeth for grasping prey. It was one of the largest coastal predators of the Jurassic Period.
It also shares key body features seen in two distinct families of prehistoric crocodiles.
Besides being heavily armoured, the species also had a tail fin, suggesting it is a missing link in the family tree of crocodiles, the researchers noted, in the paper published in the journal PeerJ.
"This fossil provides a unique insight into how crocodiles began evolving into dolphin and killer whale-like forms more than 180 million years ago," said Mark Young, of the University of Edinburgh's School of GeoSciences in Britain.
"The presence of both bony armour and a tail fin highlights the remarkable diversity of Jurassic-era crocodiles."
The specimen was identified as a new species based on the discovery of an odd-looking vertebra that formed part of its tail fin.
Some Jurassic-era crocodiles had bony armour on their backs and bellies and limbs adapted for walking on land. Another group had tail fins and flippers but did not have armour, the researchers said.