They were formed during a single low tide in an ancient sea - possibly a spring low when the sea retreats much further than normal exposing seabed that is usually covered at all stages of the tide. Normally unreachable vegetation growth may well have attracted the Iguanadon onto the soft clay bed. The sea then came in and sand was washed into the imprints. Over the eons, two different forms of stone formed from the clay and the sand in-fill. The in-fill gives an excellent impression of the soles of the feet of the the dinosaurs and even claws can be seen. The foot is three-toed with a heel pad. The surface texture is covered in ridges and bumps about the size of a penny and are obviously for grip and resemble the sole of an elephant's foot. There are different sizes of prints and casts which probably indicate (given the short access time) that a herd with young wandered down here to graze. This has gives analogue to many beasts today - notably African Elephants which exist in matriarchal herds with individuals ranging from both ends of the life spectrum.

enjoy...