New mass extinction event rewriting our Triassic past

A previously-unknown extinction event fundamentally altered prehistoric plant life 500,000 years later than we thought.

30th June 2016
Spore plant Densoisporites playfordii of the Lower Triassic (© UZH)

Spore plant Densoisporites playfordii of the Lower Triassic (© UZH)

The history of life on Earth has been a rocky one, to say the least, moving in semingly unstoppable cycles of thriving and extinction.  Not many species last longer than a few million years before being snuffed out, only to be replaced by new species.

The Circle of Life

Well, researchers from the Institute and Museum of Paleontology at the University of Zurich have added another spoke to this wheel of death – an ecological disaster from the Lower Triassic, unknown until now.

By comparing the prevalence of pollen grains and spores from 400-metre samples of Greenland’s sedimentary layers, the team discovered a massive shift in the kind of plant life that dominated the landscape, where seed ferns and conifer trees were replaced by more hardy spore plants. 

This all seems to have happened over a period of a few thousand years which, although it may seem like a long time by human standards, is practically overnight on a geological scale.

Rewriting History

This new cataclysm changes our Triassic timeline almost as much as it changed the Triassic plant life.

One of the worst extinction events in Earth’s history happened some 252 million years ago. Cheerily referred to as “The Great Dying”, it marked the end of the Permian and ushered in the Triassic.  Scientists have assumed that the environment slowly recovered during the Lower Triassic period that followed. 

Approximately 500,000 years after the major natural disaster at the boundary between the Permian and the Triassic another event altered the vegetation fundamentally and for longer © UZH
Approximately 500,000 years after the major natural disaster at the boundary between the Permian and the Triassic another event altered the vegetation fundamentally and for longer © UZH

However, analysis of the carbon isotopes from the sediment samples suggests that this new ecological upheaval happened 500,0000 years later than previously thought.

What happened?

It’s still a mystery as to what exactly caused it, but Hugo Bucher, Director of UZH’s Institute and Museum of Paleontology, suggests that there is “a link between this previously unknown global event and the enormous volcanic eruptions we know from the Lower Triassic in what's now Siberia."

Perhaps that mental image of prehistoric life that many of us had as kids – ash raining from the skies, lava blurting from volcanoes in the background – isn’t too far off after all…

You are currently reading: New mass extinction event rewriting our Triassic past - 30th June