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A Retched Discovery

21 February 2002 (All day)
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Fossil vomit. Scientists say these bullet-shaped belemnite skeletons were part of a meal that didn't agree with an ichthyosaur.

Scientists in Britain have identified what they say is the world's oldest fossilized vomit--a collection of shells from an extinct squidlike creature swallowed long ago by an ichthyosaur.

The evidence consists of shells that formed the inner skeletons of belemnites, a diet staple for ichthyosaurs, marine reptiles that plied the warm Jurassic coastal waters 160 million years ago. Geologist Peter Doyle of the University of Greenwich, United Kingdom, and Jason Wood of the Open University in Milton Keynes suspected the shells had been regurgitated by an ichthyosaur, based on its similarity to a fossil mass discovered in nearby Yorkshire that scientists thought looked like "vomite."

Doyle and Wood inspected the shells with a scanning electron microscope. They found pitting on the surface that they believe is evidence of corrosion from stomach acids. The acid marks distinguished the belemnite shells from other shells in the same area, says Wood. What's more, Doyle says, the belemnites were juveniles, indicating that "they did not die of old age." Doyle says the shells couldn't have come out the other end of the ichthyosaur because they would have damaged its internal organs. His conclusion: "This is the first time the existence of fossil vomit on a grand scale has been proven beyond reasonable doubt." The scientists presented their yet-unpublished findings at a paleontology conference at the University of Copenhagen in December.

Paleontologist Glenn Storrs of the Cincinnati Museum Center says vomiting is not an unusual dietary adaptation among carnivores--sperm whales regurgitate the hard beaks of octupuses they devour, and owls throw up bones after swallowing mice whole. While fossilized vomit has been ascribed to various fish, this may be the first assigned to a reptile, says Storrs.

Related sites
Ichthyosaur info
Belemnite info

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