Find out about Ammonites, Belemnites, Bivalve sea-shells and more.

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Ammonites

The beautiful coiled shells of ammonites are probably the most recognisable fossil in the world. Ammonites are extinct and because no soft parts of ammonites are ever found fossilised we don't know exactly what they looked like. We do know they belonged to the same group of animals as octopus, squid and nautilus so they must have been quite similar to these creatures and used their gas-filled shells to float and move up and down in the water. Even though Ammonites became extinct we know from their fossils that they were a very successful type of creature for millions of years. They lived all over the world, were adapted to all sorts of habitats and there were a great many of them living in the oceans.

Belemnites

The bullet shaped fossils of belemnites were once known in folklore as ‘thunderbolts'. They are actually the hard internal shell of an animal that would have closely resembled a squid. Belemnite fossil are very common in Jurassic aged rocks along the coast, particularly around Charmouth, where the beaches can be strewn with them after a storm.

Bivalve sea-shells

The kinds of sea-shells that you can pick up on any beach in world also appear as fossils in rocks on the Jurassic Coast. Clams and oysters are the most common, but there are many different varieties, shapes and sizes. The name ‘bivlave' comes from the fact they these creatures have two shells that close together protecting the animal inside and most bivalve fossils from the Jurassic Coast are molluscs (which means they are a particular kind of animal with particular features) 

Crinoids

The feathery tentacles and long stalks of Crinoids make them easy to mistake as plants. In fact another name for a crinoid is a ‘sea-lilly'. Crinoids are actually a type of echinoid - that is, related to starfish and sea urchins. Occasionally entire fossils of Crinoids, or even groups of them, will be found preserved together, usually on the surface of a block of limestone. Much more commonly it is only fragments of the stalks that people find. These can be easy to recognise because in cross section they are the shape of a five-pointed star.

Dinosaurs

Dinosaurs are of course the most famous prehistoric creature, and probably the most popular fossil along with ammonites and probably trilobites (...but we don't find trilobites on the Jurassic Coast). However, even though the Dorset and East Devon Coast has rocks from the entire Mesozoic era - the age of the dinosaurs - dinosaur fossils from the Jurassic Coast are very, very rare. This is mostly because the majority of the rocks on the coast formed in the sea and dinosaurs lived on land. There are some dinosaur fossils though, and even a spectacular skeleton of a dinosaur called Scelidosaurus found in 2001 near Charmouth. Not only is the skeleton probably the most complete dinosaur skeleton ever found in the UK it is also unique to Charmouth. So even though we don't have many dinosaurs we do have one that is found nowhere else in the world!

Fish

There are a great many types of fossil fish that can be found in the Jurassic and Cretaceous rocks along the World Heritage Site. Some look exactly like modern fish, others are a little more strange. These are the ones that normally have no modern relatives. The most impressive fish fossils are of sharks and rays. Shark teeth are actually quite common but the soft skeletons are rarely preserved making them very rare.

Flying reptiles

There are several kinds of flying reptiles found fossilised along the Jurassic Coast. Their skeletons are extremely delicate so their fossils are very rare indeed. Usually these fossils take the form of a single limb bone or part of the skeleton. The famous fossilist Mary Anning found a very important skeleton of a pterosaur known as Dimorphodon, one of the oldest types of flying reptile anywhere in the world.

Gastropods (snails)

Fossil sea-snails and freshwater snails are common in Jurassic and Cretaceous rocks along the Jurassic Coast. Some can be very large, about the size of a person's fist, others can be small, about the same size of a modern winkle. Purbeck marble, a famous building stone quarried in Purbeck, is made almost entirely of compacted fresh water snail shells. When it is polished it has a beautiful texture and has been used for decorative purposes in buildings all over the country.

Giant Marine Reptiles

Giant marine reptiles were the top predators in the Jurassic and Cretaceous periods. There are three main types found fossilised along the Jurassic Coast. Ichthyosaurs looked similar to sharks and dolphins and raged from only 2m up to 12m in length. They were the only marine reptile to give birth to live young. Plesiosaurs are much rarer. These strange creatures had a small head on a long neck, a barrel shaped body and four flippers for swimming. These animals were generally quite modest in body size, although the length of their necks could be extraordinary! Pliosaurs are related to plesiosaurs and were the most terrifying predators that have ever swam in the Earth's oceans. Like plesiosaurs they had four flippers and a barrel shaped body but pliosaurs had much shorter, stronger necks and long, enormously powerful jaws. The biggest of them grew to over 16m in length creating a truly terrifying predator that was bigger, more powerful and more deadly than the biggest meat eating dinosaur. The skull and jaws of one such Pliosaur are on display at Dorset County Museum. Some people call giant marine reptile dinosaurs, but this is a mistake as dinosaurs lived exclusively on land.

Insects

Insects were the first creatures to evolve and colonise the land. By the time the rocks along the Juraswsic Coast were forming insects were well developed and widespread across the globe. Their fossils can be found in many rocks along the Dorset and East Devon Coast but they are quite rare and very difficult to spot. Many insect fossils are just wings perhaps 5 mm long, others are larger. Complete insects are extremely rare but include dragonflies and beetles.

Plants

The fossilised remains of plants can be found in almost every rock type along the Jurassic Coast. Most are fragments of wood from branches or trunks. Sometimes whole sections of a tree are found with even the texture of the bark still visible. Leaves are less common but have been found in some layers. In Triassic and Jurassic aged rocks plant fossils would come from ancient types of conifers. In the Cretaceous period flowering plants appeared for the first time and their leaves and pollen have been discovered along the World Heritage Site.

Ancient reptiles

Apart from dinosaurs and the bizarre Rhynchosaurs there are fossils from other land based reptiles. In the Triassic Rocks in East Devon these fossil are very rare and come from ancient types of reptile that may even have given rise to the first dinosaurs.

Rhynchosaurs

Rhynchosaurs are a very strange type of mammal-like reptile that inhabited the Triassic desserts some 230 million years ago. Their remains are very rare but the Jurassic Coast is one of the best places in the world to find them.

Trace fossils

Fossils don't always have to be the actual remains of an animal or plant. They can also be the tracks, trails or impressions that they leave behind. There are many different types of trace fossil along the Jurassic Coast left by all sorts of different creatures. From dinosaur footprints to crab burrows, from work casts to shell imprints. There are even fossilised ripple marks! Trace fossils are incredibly valuable because they can often tell us a great deal about an ancient environment, even showing us the sorts of creatures that lived there that did not leave any other fossils behind.