Trilobite-like Creature on the Welsh Coast

Trilobite-like Creature on the Welsh Coast

Observation - Trilobite-like Creature on the Welsh Coast - UK and Ireland. Description: My sister found the remains of this creature on the beach at Cwmtydu, on the West Wales coast. Whatever it is, I imagine it often gets likened to a trilobite; but what is it? Can anybody help? Thanks.

My sister found the remains of this creature on the beach at Cwmtydu, on the West Wales coast. Whatever it is, I imagine it often gets likened to a trilobite; but what is it? Can anybody help? Thanks.