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A builder knocking a hole in a wall at the Royal Museum of Scotland
in Edinburgh has discovered fossils of a 336-million-year-old swamp tree
hidden in the stone. Billy Hardy was knocking down the west wall of the
museum last month when he noticed strange, dark lines running through the
sandstone. He immediately alerted the museum staff, who identified the marks
as fossils of a lycopsid, a ‘scale tree’ that grew in the Carboniferous
period. ‘I’ve discovered bits of fossil on various jobs before, but nothing
like this,’ says Hardy.

The trees grew up to 35 metres high with trunks a metre across. Unlike
today’s woody trees, lycopsids were supported by their tough bark, which
was covered in needle-like leaves. The giant lycopsids died out at the end
of the Carboniferous period when global warming dried up the swamps.

The museum was built in 1889 with sandstone from Hermand Quarry, West
Lothian – which in Carboniferous times was near the equator and covered
in tropical swamp. Since Hardy’s find, further building work has uncovered
more fossils of the same species in another wall.

‘It’s most intriguing,’ says Richard Bateman, curator of palaeobiology
at the museum. ‘It looks as though the whole museum is built of fossilised
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