This fossil was found in Oxford Clay, which is a Jurassic marine sedimentary rock formation – spanning as far south as Dorset, and as far north as Yorkshire. Oxford Clay ranges from the Callovian Era to the Oxfordian Era, hence we can gauge that this bone is around 160 million years ago.
Interestingly, today Oxford Clay is often used for road construction and brick making and is the source of the very popular Fletton Bricks. Oxford Clay is very advantageous for brick making, its carbon content produces fuel when firing it, meaning less external fuel is required in the brick making process.