How to recognise them

Looks like spokes on a bicycle wheel.

Fossil Info

Oldhamia is a type of trace fossil common in the Cambrian Period around 540 million years ago. In Ireland it is found in the siltstones and mudstones on Bray Head, Co. Wicklow. It looks like tiny rosettes or spokes on a tiny bicycle wheel, only about 10 - 15 mm across. Each of the little "spokes" is a burrow made by a tiny soft-bodied creature like a worm - in fact, some of the earliest evidence of animals that could move around. 

Fun Fact

These are the oldest fossils in Ireland