Pompeii of prehistoric plants

Excavating the ancestors of seed-bearing flora.

New analysis of Chinese tree fossils has revealed that they are the ancestors of the seed-bearing plants that dominate the Earth today.

Noeggerathiales was a peatforming order of plants that lived 325 to 251 million years ago (mya), before the rise of the dinosaurs and while the Earth’s land was arranged into the supercontinent Pangea.

Specimens were first discovered in the 1930s, but a dearth of well-preserved fossils prevented scientists from accurately placing them in the plant kingdom.

“Thanks to this slice of life preserved in volcanic ash, we were able to reconstruct a new species of Noeggerathiales that finally settles the group’s affinity and evolutionary importance,” says co-author Jason Hilton, from the University of Birmingham, UK.

Hilton was part of a team led by palaeontologists at the

University of Birmingham and the Nanjing Institute of Geology in China. Their paper, in the journal PNAS, describes how they studied a complete Noeggerathiales fossil preserved in a bed of volcanic ash 66 cm thick, formed 298 mya. This unique preservation provides a snapshot of a moment in time, just as the excavation of Pompeii provided a glimpse of ancient Roman life.

The team found that Noeggerathiales are more closely related to seed plants than to other fern groups, even though they appear fern-like, with complex cone-like structures evolved from modified leaves.

They also deduced that the ancestral lineage of seed plants diversified during the Devonian, Carboniferous and Permian periods (approximately 419–252 mya), and went extinct around 251 mya, during the Permian-triassic extinction event.