Land plants may have appeared 80 million years earlier than we thought

A new study drastically upends conventional wisdom about when plants colonized land, pushing back the date about 80 million years to around half a billion years ago. The new date more closely aligns with when land animals emerged, and could help advance our understanding of how and when Earth’s physical and biological systems formed. While previous estimates relied on limited fossil evidence to gauge when plants made the jump to land, researchers from the University of Bristol used “molecular clock” methods to analyze the genetic differences between living plant lineages. They then translated these differences to ages by comparing them to dated fossils to establish an evolutionary timeline for land plants as a group. Their results were published this week in Proceedings of the National Academy of Sciences. Instead of emerging 420 million years ago – the age of the oldest known fossil land plants – the study indicates land plants first appeared around 500 million years ago. Rhynia gwynne-vaughanii — 400 million-year-old fossil plant stem from Aberdeenshire, Scotland. Image courtesy of The Natural History Museum, London This pushes the emergence of land plants back into the Cambrian, a time period associated with a boom in the development and proliferation of multicellular life descriptively called the “Cambrian explosion.” Scientists believe land-dwelling arthropods first arrived on the scene mid-way through the period, which correlates to the study’s new date for land plant emergence. “Our results show the ancestor of land plants was alive in the middle Cambrian Period, which was similar…

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