From: National Museum Cardiff
Paradoxides davidis is one of the largest British trilobites ever found and is an ancient ancestor to all modern arthropods. It was discovered in West Wales in 1862. Geologists use these fossils to work out that around 500 million years ago there was a deep ocean, dividing Scotland (which at that time was connected to America) and Wales.
This image forms part of the monthly 'Curators Choice' series from Rhagor, the collections based website from Amgueddfa Cymru - National Museum Wales.
What will your favourite item be?