Fish Lizard

Ichthyosaur-Aug-17-BlogIn the 1600s some fossilised bones were discovered which were mistakenly thought to have come from a fish. At the time most scientists believed the Bible’s account of how life began. Few thought that different kinds of animals had existed millions of years before. Then, in the early 1800s, a sister and brother from Dorset discovered a whole ichthyosaurus skeleton.

Scientists classed the new discovery as a ‘link between fish and crocodiles’ and it was named ichthyosaurus meaning fish lizard. Though this was incorrect (ichthyosaurs actually evolved from reptiles rather than from fish) the findings seemed to support Darwin’s Theory of Evolution.

Despite being a reptile, the ichthyosaurus looked rather like a dolphin. This is an example of convergent evolution – animals living the same kind of lifestyle often look similar despite being unrelated (another example is the thylacine, a marsupial which looked like a dog).

Large-and-little-Ichthyosaur-Aug-17Ichthyosaurs were contemporaries of dinosaurs and swam in the oceans 250 – 90 million years ago. Most of them were quite small measuring 2 – 3m in length. But there were exceptions. Some were as short as 30cm and one was as long as 21m. That’s almost as long as a blue whale!

In the 1990s an ichthyosaurus skeleton was unearthed in Doniford Bay, Somerset. Ichthyosaurus somersetensis, as it was named, was sold to a German museum where it has remained, only now being properly studied. The report, published in the scientific journal Acta Palaeontologica Polonica, has discovered something remarkable about this particular specimen – at the time of its death the ichthyosaurus was pregnant.

Most marine reptiles, like sea snakes or turtles, come onto land in order to lay their eggs. But ichthyosaurs, unlike most reptiles, gave birth to live young. This particular fossil includes, as well as the mother’s, some bones belonging to her undeveloped embryo.

It’s only the third pregnant ichthyosaur ever to have been discovered and it helps to support the live-birth theory. Such a shame that it was 30 years before we got round to studying the remains. It just goes to show – you may not have to go out in the field to make new discoveries. Just pay a visit to your nearest museum!

Another place you might like to visit is the Nature section of our site. It’s packed full quizzes on animals, plants and all else ecological. If you love the natural world then it’s the place to go to test your natural knowledge!

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