February’s Object of the Month is a dinosaur footprint. It was chosen as Object of the Month by Sarah Kenyon, Natural Sciences Officer.
The footprint was made by a young Iguanodon dinosaur 145 to 100 million years ago during the early Cretaceous period. This cast of the footprint was fossilised in chalky limestone rock. You are looking at the underside of the three-toed footprint. It was bought at a quarry near Swanage in Dorset during the twentieth century.
Footprints can provide information about the type of dinosaur and the size, weight and speed of these extinct animals. This one was identified by a geologist as the footprint of a young Iguanodon. It was preserved when the imprint left by the foot of the Iguanodon was quickly filled with lime rich mud from a lake or stream. The limy mud eventually turned to limestone rock and formed a cast of the footprint on the underside of the layer of rock.
Iguanodon was one of the most successful and widespread dinosaurs. Fossils have been found in Britain, Germany, Spain, Belgium and the United States of America. The name Iguanodon means ‘iguana tooth’. It is pronounced “ig-WHA-noh-don”. Boulenger and van Beneden named the dinosaur in 1881. An adult Iguanodon was up to ten metres long and weighed almost five tons. It is now thought that Iguanodon could walk on all fours or on two legs. The dinosaur had three toes, five fingers and large thumb spikes, which may have been used to defend against predators. It had a horny beak and the teeth were chewing teeth so it ate plants.
Museum Dinosaur Fossils
Saffron Walden Museum has only five dinosaur specimens in the geology collection. They are this fossilised dinosaur footprint; a cast of a flying reptile fossil, a Pterosaur from Solnhofen in Germany; and three replicas in a school loan box. The replicas are of a tooth from a plant-eating dinosaur, the tooth of a meat-eating dinosaur and the footprint of a small carnivorous Theropod dinosaur which walked on two legs.
The dinosaur footprint is on display in the museum until 28 February 2017 where you can discover more about fossilisation.