Much of southern Warwickshire is underlain by layers of clay, limestone, sandstone and ironstone dating back to the Jurassic Period. The rock beds are occasionally seen in quarries, road cuttings and other excavations. Harder rocks such as limestones and ironstones tend to cap hills and ridges. Examples include the Burton Dassett Hills and Edge Hill. Limestones can be seen at Cross Hands Quarry. The softer clays form lowlands.
Warwickshire’s Jurassic rocks formed between about 200 and 170 million years ago as layers of mud and sand in warm, shallow seas. These covered much of central England at that time. The fossils found in the Jurassic rocks are the remains of creatures that lived in the ancient seas. The shells of ammonites and other sea-creatures including Devils’ toenails are the most familiar. Bullet-like belemnites represent the internal shell of extinct squid-like animals.
Clay and limestone beds, termed ‘Blue Lias‘, are still quarried for Rugby Cement at Southam. In the past these beds yielded the skeletons of ichthyosaurs and plesiosaurs – real Jurassic sea-dragons. The Hornton Stone is slightly younger than the Blue Lias. It is a bed of rusty ironstone, quarried for building stone around Edge Hill. We now know that this rock formed as iron-rich sand in a shallow current-swept coastal area. The iron appears to indicate the former presence of rusty-coloured tropical soil on nearby Jurassic islands. Rarely, dinosaur bones have been found in limestones of Jurassic age (see below).
A real Warwickshire dinosaur!
Jurassic Warwickshire was dominated by a shallow sea that was inhabited by a range of amazing sea-creatures. True dinosaurs, though living at this time, were land-dwelling animals. For this reason, dinosaur remains are very rare in Warwickshire.
However, the Warwickshire Museum is now the new home for a unique collection of fossil remains – the bones of a new species of dinosaur.
The story began 170 million years ago when the carcass of a Megalosaurus-like carnivorous dinosaur was washed up on a beach over what is now southern Warwickshire. The bones were covered by layers of shelly sand which eventually became deeply buried and hardened into limestone layers. Millions of years later, the limestone rock beds were revealed at the land’s surface, as the modern landscape slowly emerged. There they remained until the 1960s, when a number of the shattered bones were dug up in a local quarry.
For several decades the rock fragments and the bones that they contain were cared for by Birmingham Museums and Art Gallery. They were recently returned ‘home’ to Warwickshire where they have undergone detailed scientific investigation and documentation. When the work is finished, a selection of the bones will go on display at the museum.
The finds are some of the most important dinosaur remains to have been discovered in the United Kingdom in recent years. We now know that they represent a completely new species of dinosaur – a meat-eater that has been named Cruxicheiros newmanorum. ‘Cruxicheiros‘ (pronounced Croos-i-ky-ros) means ‘Cross Hand’ in Latin and Greek and is named after the disused quarry site where the bones were discovered. ‘Newmanorum’ refers to the Newman family, on whose land the bones were found.