Ammonite
The Cenomanian Limestone is the oldest chalk in East Devon and is a sandy type of chalk. It ‘s packed with fossils, particularly ammonites, but also sea shells, sea urchins, sponges and even shark’s teeth.
Fossil Finder Database 2022
Ammonite
What’s a nodule? This ammonite, Asteroceras stellare, lies within a massive Stellare nodule. The rock is known as a septarian nodule, that is a hard, compact mass of sedimentary rock with angular cracks running through it. They are also called concretions. The nodule formed around the ammonite, preserving it from being crushed as more layers of sediment settled.…
Bivalve oyster shell
Oyster shells are distinctive in that they are built up of many fine layers. This specimen is unusual because it appears to have some of the soft tissue preserved in the hinge (the tip of the shell). Phosphorus is an essential element in animals’ diets – when it was released as this oyster decayed, it…
Bivalve oyster shell
Zig-zag growth lines Here is an oyster with two shells that opened and closed. As you can see, the shell edges have a zig-zag pattern and can be mistaken for jaws. This pattern made the shells robust. The parallel lines above and below the ‘jaws’ are growth lines charting the life of the shell. Oysters…
Bivalve shell
Bivalves from the Cornbrash rocks of Dorset are usually quite poorly-preserved. But what is striking is how similar they are to the modern day cockle, Cardium. Bivalves are a very old and successful group. They were alive during the reign of the dinosaurs and survived the great Cretaceous-Tertiary extinction event.
Bivalve oyster shell
Zig-zag growth lines Here is an oyster with two shells that opened and closed. As you can see, the shell edges have a zig-zag pattern and can be mistaken for jaws. This pattern made the shells robust. The parallel lines above and below the ‘jaws’ are growth lines charting the life of the shell. Oysters…
Bivalve shell
Spiny shell This bivalve, Spondylus spinosus, has taken defence to an extreme, developing long, sharp spines. However, they may actually have been of more use in preventing the shell from sinking in the soft ooze at the bottom of the chalk sea.
Ammonite
One of the more unusual ammonites from the Blue Lias near Lyme Regis. Ammonites have a spiral shell divided into chambers. It could control its buoyancy in the water by filling the chambers with gas and water. The soft body of the ammonite only took up the last half whorl of the shell. Only the shells…
Brachiopod shell
This is a species from a time in the Middle Jurassic period when brachiopod diversity was quite high. Earlier and later, extinctions reduced brachiopod diversity.