A MISSION to solve the mystery of a missing fossilised hippopotamus tooth that was first discovered 60 years ago has been set in stone.

Wynyard Woodland Park – close to where the fossilised hippopotamus tooth was found in 1958 – has created a permanent tribute.

A 3.6m long sculpture of a hippo skeleton created by artist Andrew McKeown has been installed in the adventure play area.

Modelled in clay then cast in stone, it is set within the sand pit where it can be unearthed by visitors.

The discovery of the tooth was just four miles north-west of Stockton – making it the most northerly place on the planet in which the hippopotamus is known to have lived.

It was identified as a molar tooth belonging to the same species of hippo that lives in Africa today.

Anybody who knows exactly where the tooth was found is asked to email stocktonhippo@hotmail.com.