British waters are reassuringly free of deadly reptiles today – but 163 million years ago a sea crocodile dubbed the ‘Melksham monster’ lurked on our shores.
Scientists have established that the 10-foot long creature, named after the town in Wiltshire where its fossil was unearthed, lived in the warm, shallow seas that covered much of what is now Europe.
The heavily damaged fossil had been sitting in the archives of London’s Natural History Museum since 1875.
Its identification reveals that an extinct group of aquatic reptiles evolved millions of years earlier than was previously thought.
The creature’s powerful jaws and large, serrated teeth allowed it to feed on large prey including prehistoric squid, and it was one of the most fearsome predators of its day.
Jurassic giant: An artist’s impression of a prehistoric croc
Davide Foffa, a PhD student in the University of Edinburgh’s School of GeoSciences, who led the study, said: ‘It’s not the prettiest fossil in the world, but the Melksham Monster tells us a very important story about the evolution of these ancient crocodiles and how they became the apex predators in their ecosystem.’
Modern crocodiles are largely found in tropical regions of Africa, Asia, the Americas and Australia.
However their ancient ancestor is named Ieldraan melkshamensis after the Wiltshire town of Melksham where it was found preserved in clay.
Its name also means ‘older one’ because it was thought until now that the sub-family of prehistoric crocodiles to which it belongs – known as Geosaurini – originated in the Late Jurassic period, between 152 and 157 million years ago.
In fact, the latest discovery – together with detailed re-analysis of existing fossil evidence – suggests the group arose millions of years earlier, in the Middle Jurassic.
This new fossil, seen here showing it’s distinctive teeth, has been dubbed the Melksham Monster after being found in the Wiltshire town
It was identified as a new species based on distinctive features of its skull, lower jaw and, in particular, its teeth.
Dr Steve Brusatte, of the University of Edinburgh’s School of GeoSciences, who was involved in the study, said: ‘The Melksham Monster would have been one of the top predators in the oceans of Jurassic Britain, at the same time that dinosaurs were thundering across the land.’
This was one tough old croc in life and death
The study, published in the Journal of Systematic Palaeontology, was carried out in collaboration with the Natural History Museum.
Mark Graham, senior fossil preparator at the Natural History Museum, said: ‘The specimen was completely enclosed in a super-hard rock nodule with veins of calcite running through, which had formed around it during the process of fossilisation.
‘This unyielding matrix had to be removed by force, using carbon steel tipped chisels and grinding wheels encrusted with industrial diamonds.
‘The work took many hours over a period of weeks, and great care had to be taken to avoid damaging the skull and teeth as they became exposed. This was one tough old croc in life and death.’