A creature resembling a hybrid dolphin and crocodile has been identified by scientists examining fossil remains which were discovered more than a century ago.
The new species, named Tyrannoneustes lythrodectikos, was a marine "super-predator" that lived 163 million years ago.
It belonged to a group of ancient crocodiles with dolphin-like features.
An amateur fossil hunter found the reptile's partial skeleton in a clay pit near Peterborough in the early 1900s.
Experts have only now been able to confirm the identity of the remains, housed at The Hunterian Museum at the University of Glasgow.
The animal had pointed, serrated teeth and a large gaping jaw suited to feeding on large-bodied prey.
It represents a missing link between marine crocodiles that fed on small prey and their super-sized relatives.
Dr Mark Young, from the University of Edinburgh, said: "It is satisfying to be able to classify a specimen that has been unexamined for more than 100 years, and doubly so to find that this discovery improves our understanding of the evolution of marine reptiles."
Dr Neil Clark, palaeontology curator at The Hunterian Museum, added: "Little research has been done on this specimen since it was first listed in 1919.
"It is comforting to know that new species can still be found in museums as new research is carried out on old collections.
"It is not just the new species that are important, but an increase in our understanding of how life evolved and the variety of life forms that existed 163 million years ago in the warm Jurassic seas around what is now Britain."
The research appears in the Journal of Systematic Palaeontology.