Plesiosaur puzzle


An exciting new resident arrived at the Museum recently, having lain in the Cambridgeshire earth for around 165 million years. Discovered in a quarry near Peterborough, the skeleton of a 5.5 metre plesiosaur has been donated to the Museum and is now awaiting reconstruction and further study in our labs.

Plesiosaurs were long-necked sea creatures that lived during the time of the dinosaurs, but died out 66 million years ago.

Artist’s impression of Muraenosaurus leedsii, a similar plesiosaur from the Middle Jurassic of Europe. Image by Nobumichi Tamura.

The fossilized remains of the marine reptile were discovered at a site owned by building product manufacturer Forterra, which has kindly allowed the material to be added to the Museum’s collections.

The creature was first spotted by Oxford Clay Working Group member Carl Harrington who noticed a tiny fragment of bone sticking out of the clay. Over the course of four days, Carl and eight others dug up more than 600 pieces of fossilised bone. Carl then spent over 400 hours cleaning and repairing the specimen.

I’d never seen so much bone in one spot in a quarry. As I was digging amongst the wet clay, the snout of a plesiosaur started to appear in front of me. It was one of those absolute ‘wow’ moments – I was the first human to come face to face with this reptile.

The plesiosaur’s neck vertebrae

The plesiosaur had a 2.5 metre long neck, a barrel-shaped body, four flippers and a short tail. Its skull is still preserved inside a block of clay, and the painstaking task of removing it will now be undertaken here.

A CT scan of the plesiosaur's skull, which is still inside a clay block
A CT scan of the plesiosaur’s skull, which is still inside a clay block

DrJames Neenan, one of our research fellows, and Professor John Hutchinson from the Royal Veterinary College have already CT-scanned the block to reveal the location of the bones inside. This will help in removing it from the clay.

Next week pupils from a visiting secondary school will get the chance to see the plesiosaur find for themselves and to ask our Earth Collections manager Dr Hilary Ketchum all about it. Hilary says:

We are so excited that the plesiosaur has come to the Museum where it will be used for research, education and display.

The plesiosaur’s ribs and vertebrae still inside the rock
The plesiosaur’s ribs and vertebrae still inside the rock

Hilary will now begin the task of reconstructing the plesiosaur from the remains you can see in the photos here – a combination of individual separate bones and those still contained in clay nodules. Ultimately, we hope to articulate and suspend the specimen for public display.

Hilary holds out the plesiosaur’s arm bone (humerus)
Hilary holds out the plesiosaur’s arm bone (humerus)

Part of the study will be to determine whether this is a known or new species of plesiosaur. Early indications suggest that it might be a species new to science, but more investigation is needed before we will know for sure.

Watch this space…


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