Thecosmilia Fossil

These fragments of Thecosmilia Fossil were found at Rock Edge in Headington, and are part of our History of Headington collection.

Rock Edge is a remnant of the limestone quarries formerly worked extensively throughout Headington. The rocks exposed in the cliff face are of Upper Jurassic age, around 140-150 million years old.
It is the site of a former coral patch reef, where fossilised corals and mollusc shells can be seen. Towards the north-eastern end it becomes more layered with cemented limestones containing small ooliths (tiny rounded grains) and broken shell fragments. These represent the sandy sea-floor environment around the former coral reef.

Corals are invertebrate animals belonging to a large group of colourful and fascinating animals called Cnidaria. Other animals in this group that you may have seen in rock pools or on the beach include jelly fish and sea anemones. Thecosmilia is an extinct type of stony corals that lived from the Jurassic to the Cretaceous age.