A fossilised headstone in the cemetery

I noticed this interesting headstone in the local cemetery which contains an unusual fossilised wood. In fact there are shapes of two distinct 'plants', the biggest of which seems like a small tree. The segmentations are like those from a bamboo,

There is a limestone quarry less than two hundred yards along the valley. I've never seen such large fossils near here, so I assume that it was imported from another quarry. All along the carboniferous limestone strata which underlie the Cotswold landscape there are quarries of notable stone. They were the source of all the main building block material for local settlements back through time, with each quarry producing distinctive types and colours of the stone.