Lemmysuchus obtusidens lived around 164 million years ago during the Middle Jurassic Period and was a member of an extinct group of marine crocodile relatives called teleosaurs. 'With a metre-long skull and a total length of 5.8 metres, it would have been one of the biggest coastal predators of its time,' says University of Edinburgh palaeontologist Michela Johnson, who helped to untangle the identity of Lemmysuchus. The specimen, housed in the Museum, was dug up by collectors in the early twentieth century from a clay pit quarry near Peterborough, Cambridgeshire. However, it was incorrectly categorised with the remains of other sea crocodiles found in the same location. In a study published in the Zoological Journal of the Linnean Society, an international team of scientists took a fresh look at the fossil skeleton and gave it a new classification and scientific name.

A marine monster Lemmysuchus lived in shallow sea waters around the coast of land that would become modern-day Europe. Its broad snout and large blunt teeth evolved for crushing shelled prey such as turtles - in contrast to its close relatives that had longer snouts and thinner teeth for catching fish. Jumble of bones Palaeontologists can find it hard to identify a new species as they normally work with incomplete fossil skeletons. This makes it difficult to match different finds to an already known species or decide that they have found a new species. The exact relationship between Lemmysuchus and its close relatives had been misunderstood as scientists had previously wrongly assigned some other fossil finds to the same species. The current researchers performed a careful anatomical comparison on the all bones and referred them to the main type specimen in the Museum.