The new specimens, which were killed and fossilised quickly when volcanic ash smothered them underwater more than 500 million years ago, show details never befo

The new specimens, which were killed and fossilised quickly when volcanic ash smothered them underwater more than 500 million years ago, show details never before seen in any trilobite... First sentence of TFA. This is not a claim that all trilobites were made extinct by volcanic ash, but that these fossils were the result of an ashfall, by which previously unavailable anatomical detail was preserved. The headline is misleading, but even the shallowest read of the article would have mooted your speculation.