150-million-year-old oyster which is ten times normal size probably contains the world’s biggest pearl – but no-one wants to open it to find out

The giant oyster (left, shown next to a regular oyster) was hauled up in the Solent, on the British coast, and found in the nets of the trawler boat when it returned to port. After layers of mud were washed off, it was clear the item was a huge fossilised shell that measured seven inches wide and three inches thick.