Dinosaur Museum Sandown Esplanade
Where do you find dinosaurs?
One of the best places in the world to start looking is the Isle of Wight. This tiny lozenge-shaped island situated in the English Channel boasts over a dozen different types of dinosaur. Well, the fact is that dinosaurs became extinct everywhere 65 million years ago but they left plenty of bones, teeth, footprints, eggs and droppings for us to find later. The Isle of Wight is so rich in these fossilized remains that it has recently earned the nickname of Dinosaur Island.
The Isle of Wight isn't what it used to be. It used to be a subtropical paradise, but you have to cast your minds back 115 million years. Some people have great difficulty comprehending this immense period of time, so it may help to imagine 57.5 million years and double it. At that time the earth was slap bang in the middle of what some geologists call the 'Age of Reptiles' and the Isle of Wight wasn't an Island at all. Instead it was part of a larger land mass situated much closer to the equator and hence it had a correspondingly warmer climate. The land was infested with the sort of creatures you can only see nowadays if you are not too fussy about what kind of mushrooms you eat. These prehistoric monsters were named dinosaurs in 1842 to distinguish them from other kinds of ancient reptiles which could swim or fly. Although dinosaurs could do neither of these things they could stand up straight, which was enough to give them dominance of the terrestrial environment and a widespread distribution. In other words they were as common as muck, but the sea was teeming with sea life as well. Countless thousands of squid -like shellfish called ammonites abounded, so it was just as much the 'Age of Ammonites' as reptiles. Yet quite inexplicably 65 million years ago the age of both was suddenly over as many other life forms kicked the geological bucket. Since then the crust of the earth has continued to break up into segments known as plates and each plate has moved relative to the others like the skin on a giant rice pudding. The exact spot which ended up being the Isle of Wight moved gradually northwards at the rate a fingernail grows, which doesn't sound very much unless you wait a few tens of millions of years. Eventually the last Ice Age receded, the sea level rose and about seven thousand years ago the 'Peninsula of Wight' finally became detached from mainland Britain to become and Island, an event which some experts think was masterminded by the Isle of Wight ferry company.
To find your dinosaur you have to look in sedimentary rocks of the right age and type. For a rock to have any chance of containing something dinosaur-ish it must not only be the right age (200 - 65 million years old), but it must also have been laid down in fresh or brackish water. Dinosaurs did not live in the sea so their corpses are much more likely to be flushed into rivers or buried in lagoons, the sediments much later turning into sandstone, shale or clay. This brings us to the Isle of Wight of today, where a likely layer of freshwater deposits 115 million years old is exposed along southern coastal cliffs like the jam in the side of a sponge cake. As far as England goes you can see this 'dinosaur layer' at ground level on the Isle of Wight. It is hidden to the west, north and east under thick layers of younger rocks, only peeping through in the odd quarry or brick pit. The dinosaur layer is actually a series of layers hundreds of metres thick, only some of which are fossiliferous (or dinosauriferous). These strata run along the Islands coast for miles and are best displayed at Brighstone and Brook bays. Despite their great age most of the rocks have never truly solidified, but remain as a soft blue clay which the locals call 'blue slipper' on account of it's vulnerability to the erosive action of the sea. Each winter brings a series of high spring tides which combine with storm force winds to erode our tiny island at an alarming rate. Constant cliff falls, mud flows and landslips mean that the Isle of Wight is disappearing fast in geological terms and will probably vanish for good in a mere 50 thousand years. All of this will be disappointing reading for the average Isle of Wight resident but is great news for the potential fossil collector who can rely on the elements to do most of the work.
Individual petrified dinosaur bones are being washed out of the slippery mud flows and crumbly cliffs in large quantities, but the vast majority are sucked out to sea or ground down to pebbles on the shingle beaches. Complete skeletons are much more of a rarity, yet on average a nearly whole dinosaur will reappear every few years. In the last ten years alone three important, near-complete dino-corpses have been collected.
The commonest and best known of all the island dinosaurs is a plant-eater called Iguanodon. This creature usually walked on it's back legs, but could sometimes use the smaller front ones as well, it's most distinctive feature was a spike on each thumb. Iguanodon stood about 5 metres high and was 10 metres long thanks to an impressive tail. Fossilized bones of this creature are turning up on island beaches almost daily, but it is much harder to find a good example of the leaf-like teeth which resemble those of a modern Iguana (hence the name). As many as three hundred Iguanodon skeletons have fallen out of the Island's cliffs since records began, which is hardly surprising when you consider that they must have lived in huge herds. Many more must still be hidden beneath our feet.
Another well known early Isle of Wight resident was Hypsilophoden, which looked something like a small Iguanodon. About thirty complete skeletons have been found of this two legged, fast running vegetarian, and they are all animals about two metres long. The Isle of Wight also had it's own armoured dinosaur called Polacanthus, a sort of prehistoric reptilian tank equipped with spines and a thick defensive shield. There have only been three decent Polacanthus skeletons ever found, the best being unearthed in 1994 by a local woman out walking her dog. Unfortunately, none of these Polacanthi has a head so we can only guess that the skull was small and bony enough to protect the minuscule brain. In 1992 lots of bones of a Brachiosaurus-like dinosaur were pieced together to make about 30 per cent of a skeleton. This discovery may help to make sense of the countless bits and pieces of long necked vegetarian dinosaurs which have been found here over the years. All we can say at the moment is that there definitely were creatures like Brachiosaurus and Diplodocus on the Isle of Wight although what species they belong to is anybody's guess.
Enough of vegetarians. When you mention dinosaurs to most people they invariably think of the famous Tyrannosaurus rex, which used to be the biggest meat-eater of them all until some spoilsport found a bigger one in Argentina which has been named Gigantosaurus. T. rex will always get the publicity, however, because of it's association with 'Jurrasic Park', a pop group with flared trousers and a brand of cooking oil. As for Isle of Wight meat-eaters, you could probably fit all of their fossilized bones into a Fiat Panda and none of them would belong to T. rex. What we had instead was Megalosaurus, a smaller creature with three fingers rather than two. Judging by the fossil evidence there weren't many Megalosaurus knocking about, but luckily a nearly complete one turned up recently and is still being cleaned up for it's debut in next year's dinosaur books.