Oxford Clay

The Oxford Clay is a special kind of rock made from very old sea mud. It is found under much of southeast England, from Dorset in the west to Yorkshire in the north. This rock formed long ago when dinosaurs lived, during a time called the Jurassic period, especially in the Callovian and Oxfordian ages.

Oxford Clay has two main parts. The lower part, called the Peterborough Member, is full of fossils and organic material, and is often called lower Oxford Clay. The upper part includes the Stewartby Member and the Weymouth Member, and it has fewer fossils and more limestone.

You can see Oxford Clay near cities like Oxford, Peterborough, and Weymouth. It is often found in quarries in these areas. The rock changes from shale to mudstone near the top of the lower layer, and the middle and upper layers are sometimes separated by a special kind of limestone.

Palaeontology

The Oxford Clay is famous for its many fossils of fish and invertebrates. These fossils are often very well preserved. Animals that lived in the ancient Oxford Clay Sea include plesiosaurs, marine crocodiles, ichthyosaurs, cephalopods like belemnites, bivalves such as Gryphaea, and many gastropods. Dinosaur eggs have also been found in the lower part of the Oxford Clay in Cambridgeshire, England.

Fossil Content

The Oxford Clay has many fossils from animals that lived in the sea long ago. Some parts of this rock have pieces of dinosaurs called euronithopods found in a place called Cambridgeshire in England.

There are also fossils of flying reptiles called pterosaurs, as well as other sea creatures like ichthyosaurs, plesiosaurs, fish called pachycormiformes, and thalattosuchians.

Ornithischians of the Oxford Clay
Genus	Species	Location	Stratigraphic position	Material	Images
Callovosaurus	C. leedsi	Cambridgeshire	Lower	"Femur."
Lexovisaurus	L. durobivensis	Cambridgeshire Dorset	Lower	A holotype pelvis.
	Indeterminate	Bedfordshire
Loricatosaurus	L. priscus	Cambridgeshire	Lower
Sarcolestes	S. leedsi	Cambridgeshire	Lower	"Partial mandible."

Saurischians of the Oxford Clay
Genus	Species	Location	Stratigraphic position	Material	Images
Cetiosauriscus	C. stewarti	Cambridgeshire	Lower	"Rear half of a skeleton."
Eustreptospondylus	E. oxoniensis	Oxfordshire	Upper	Disarticulated skull and skeleton, with some referred limb elements.
Sauropoda	Indeterminate	Wiltshire Cambridgeshire
Theropoda	Indeterminate	Oxfordshire	Middle
Metriacanthosaurus	M. parkeri	Weymouth	Upper

Genus	Species	Images
Cryptoclidus	C. eurymerus
	C. richardsoni
Eardasaurus	E. powelli
Liopleurodon	L. ferox
	L. pachydeirus
Marmornectes	M. candrewi
Muraenosaurus	M. leedsi
Pachycostasaurus	P. dawnii
Peloneustes	P. philarchus
Picrocleidus	P. beloclis
Pliosaurus	P. andrewsi
Simolestes	S. vorax
Tricleidus	T. seeleyi

Genus	Species	Images
Lemmysuchus	L. obtusidens
Charitomenosuchus	C. leedsi
Steneosaurus	S. edwardsi
	S. durobrivensis
Neosteneosaurus	N. edwardsi
Mycterosuchus	M. leedsi
Metriorhynchus	M. superciliosus
Thalattosuchus	T. superciliosus
Gracilineustes	G. leedsi
Suchodus	S. brachyrhynchus
	S. durobrivensis
Tyrannoneustes	T. lythrodectikos

Economic use

Oxford Clay is soft and porous, which makes it good for building roads. It is also used to make the Fletton stock brick. These bricks helped build much of London. A good thing about Oxford Clay for bricks is that it has carbon. This carbon helps give fuel when the bricks are fired, so we need less fuel from outside.