‘Pompeii of prehistoric plants’ unlocks evolutionary secret: study

Spectacular fossil plants preserved in a volcanic ash fall in China shed light on an evolutionary race 300 million years ago, which was eventually conquered by the seed-bearing plants that dominate so much today.

New research on fossils found in the ‘Pompeii of prehistoric plants’ in Wuda, Inner Mongolia, shows that the plants, called Noeggerathiales, were highly developed members of the genus from which seedlings come.

Noeggerathiales were important peat-forming plants that lived about 325 to 251 million years ago. The understanding of their relationship with other plant groups has so far been limited by examples that have been poorly preserved.

The fossils found in China have enabled experts to find that Noeggerathiales are more closely related to seed plants than to other fern groups.

They are no longer considered an evolutionary cul-de-sac, but are now recognized as advanced tree ferns that developed complex conical structures of modified leaves. Despite their sophistication, Noeggerathiales have fallen victim to the drastic environmental and climate change of 251 million years ago that destroyed swamp ecosystems worldwide.

The international research team, led by paleontologists at the Nanjing Institute of Geology and Paleontology and the University of Birmingham, today presented its findings in the Proceedings of the National Academy of Sciences (PNAS).

Co-author, dr. Jason Hilton, a lecturer in paleobiology at the University of Birmingham’s Institute for Forest Research, said: have to identify their place in the life story.

“The spectacular fossil plants found in China are known as the plant equivalent of Pompeii. Thanks to this piece of life preserved in volcanic ash, we were able to reconstruct a new species of Noeggerathiales that eventually settled the group’s relationship and evolutionary importance.

“The fate of the Noeggerathiales is a serious reminder of what can happen when even very advanced life forms face rapid environmental change.”

The researchers studied complete Noeggerathiales preserved in a 66 cm thick volcanic bed formed 298 million years ago, suffocating all the plants growing in a nearby swamp.

The ash prevented the fossils from rotting or being digested, and preserved many complete individuals in microscopic detail.

Lead author Jun Wang, professor of paleobotany at the Nanjing Institute of Geology and Paleontology, said: ‘Many specimens were identified in excavations in 2006-2007 when some leaves were visible on the surface of the ash. each other and a stem below – we unveiled the crown on the site, but then fetched the samples completely to take them back to the laboratory.

“It took many years to study it fully and the additional specimens we found recently. The complete trees are the most impressive fossil plants I have seen, and because of our careful work they are also some of the most important to science.”

The researchers also concluded that the ancestors from which seedlings evolved, along with the earliest seed plant radiation, diversified during the Devonian, Carboniferous, and Permian periods and did not become extinct as previously thought.