'Dinosaur' vomit discovered in quarry

The vomit is 160 million years old

Fossilised "dinosaur" vomit has been discovered in a quarry in Peterborough.

Scientists believe the vomit, estimated to be 160 million years old, gives vital clues to the feeding habits of ichthyosaurs, marine reptiles that lived at the same time as the dinosaurs.

Detailed analysis has revealed the remains of dozens of belemnites - an ancient sea creature - within the fossilised substance.

Peter Doyle has studied the prehistoric vomit

Professor Peter Doyle, of the University of Greenwich, believes the belemnite shells contained in the vomit indicate that they were regurgitated.

The process is shared by the modern-day sperm whale.

Professor Doyle said: "It is highly unlikely that these shells passed through the ichthyosaur's intestines and were excreted as droppings because they would have damaged the soft tissue of the reptile's internal organs.

"The only alternative is that the shells were vomited out in much the same way that modern-day sperm whales regurgitate the indigestible beaks of squid."

Chronic indigestion

Further examination has revealed distinctive etching marks on the shells.

These are believed to have been caused by the digestive fluids from the gut of the ichthyosaur.

Ichthyosaurs swam in the ocean when dinosaurs walked on land.

They appeared slightly earlier than dinosaurs (250 million years ago) and lived until about 90 million years ago.

Professor Doyle said: "The Peterborough belemnite shells have revealed acid etching marks, proving that they had been eaten by a predator.

"The fact that most of these belemnites were juveniles reinforces our view that they did not die of old age."

The research team believes the acid etching marks provide the first hard evidence that ichythosaurs vomited the inedible parts of shellfish to avoid internal damage and chronic indigestion.