Fossilisation

Study co-author, Dr Katherine Dobson, of the University of Strathclyde, said the natural fossilisation had “achieved almost perfect preservation”.

Pollen in the fossil record main Pollen's sporopollenin outer sheath affords it some resistance to the rigours of the fossilisation process that destroy weaker objects; it is also produced in huge quantities.

While it has long been debated whether the gap is a result of fossilisation or relates to an actual event, recent work indicates the gap period saw a drop in atmospheric oxygen levels, indicating some sort of ecological collapse.