Wignall now suspected he was onto something big.
The expedition spent a month amassing samples.
They shipped back 20 crates of rock to Britain.
It seemed at last that the Permian killer might reveal its secret.
Back in Leeds, Wignall realized he'd stumbled on a treasure trove of fossils.
Buried in the rock samples were thousands of them.
Many so small, they had to be extracted in an acid bath.
His team was overwhelmed by what they'd got.
We were so excited with this story that we were working weekends
and just buckets and buckets of rocks all being broke down,
we, excitingly we were just sieving them through, getting all the fossils out.
Wignall's sediments began to reveal the most detailed account of the extinction ever uncovered.