Ancient bones discovered more than a century ago have been identified as a new species of marine super-predator.
The partial skeleton was found by an amateur palaeontologist in a clay pit near Peterborough in the early 1900s, and it has since been held by The Hunterian Museum at the University of Glasgow.
Now, researchers say they've established that the animal is distantly related to modern-day crocodiles.
"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," says lead researcher Mark Young of Edinburgh University.
The remains, which include a jawbone and teeth, reveal a creature that was rather similar to a dolphin. Its pointed, serrated teeth and large gaping jaw meant it would have been suited to feeding on large-bodied prey.
The species is the oldest-known member of this group of animals, and helps scientists better understand how marine reptiles were evolving about 165 million years ago.
The 30-foot animal represents a missing link between marine crocodiles that fed on small prey, and others that were similar to modern-day killer whales, and which fed on larger prey.
The team's named the creature Tyrannoneustes lythrodectikos, meaning 'blood-biting tyrant swimmer'.