Spectacular fossil plants preserved in a volcanic ash fall in China shed light on an evolutionary race 300 million years ago that was eventually won over by the seed plants that dominate so much of the Earth today. today.
New research into fossils found at the “Pompeii of Prehistoric Plants” in Wuda, Inner Mongolia, reveals that the plants, called Noeggerathiales, were highly evolved members of the lineage from which seed plants descended.
Noeggerathiales were important peat-forming plants that lived about 325 to 251 million years ago. Understanding of their relationships to other plant groups has so far been limited by poorly preserved examples.
Fossils found in China have allowed experts to determine that Noeggerathiales are more closely related to seed plants than to other fern groups.
No longer considered an evolutionary dead end, they are now recognized as advanced tree ferns that evolved complex cone-like structures from modified leaves. Despite their sophistication, the Noeggerathiales fell victim to the profound environmental and climatic changes of 251 million years ago that destroyed wetland ecosystems globally.
The international research team, led by paleontologists from the Nanjing Institute of Geology and Paleontology and the University of Birminghamtoday published its findings in the Proceedings of the National Academy of Sciences (PNAS).
Co-author Dr Jason Hilton, Reader in Paleobiology at the University of Birmingham’s Institute of Forestry Research, commented: “Noeggerathiales were recognized as early as the 1930s, but scientists have treated them as a” taxonomic football”, endless without anyone. identify their place in the history of life.
“The spectacular plant fossils found in China are becoming the plant equivalent of Pompeii. Thanks to this slice of life preserved in the volcanic ash, we were able to reconstruct a new species of Noeggerathiales which finally establishes the affinity and the evolutionary importance of the group.
“The plight of the Noeggerathiales is a stark reminder of what can happen when even highly advanced life forms are faced with rapid environmental change.”
Researchers studied complete Noeggerathiales preserved in a 66cm-thick volcanic ash bed formed 298 million years ago, smothering all plants growing in a nearby swamp.
The ash prevented the fossils from rotting or being consumed, and preserved many complete individuals in microscopic detail.
Lead author Jun Wang, a professor of paleobotany at the Nanjing Institute of Geology and Paleontology, commented, “Many specimens were identified during excavations in 2006-2007 when a few leaves were visible on the surface of the ashes. It looked like they might be connected to each other and to a stem below – we revealed the crown in place, but then extracted the complete specimens to bring back to the lab.
“It has taken many years to fully study them and the additional specimens we have found more recently. Complete trees are the most impressive fossil plants I have seen and thanks to our painstaking work they are also among the most important for science.
The researchers also deduced that the ancestral line from which the seed plants evolved diversified alongside the radiation of the first seed plants during the Devonian, Carboniferous and Permian periods, and did not die out rapidly as we thought so before.
Reference: “Ancient noeggerathialean reveals that the seed plant sister group diversified along with the seed plant primary radiation” by Jun Wang, Jason Hilton, Hermann W. Pfefferkorn, Shijun Wang, Yi Zhang, Jiri Bek, Josef Pšenicka , Leyla J. Seyfullah and David Dilcher, March 8, 2021, Proceedings of the National Academy of Sciences.
The research team consisted of experts from: Nanjing Institute of Geology and Paleontology; University of Birmingham; Chinese Academy of Sciences; Shenyang Normal University; Academy of Sciences of the Czech Republic, Prague; Center for Paleobiodiversity, Pilsen, Czech Republic; University of Vienna; Indiana Geological and Water Survey, USA; and Indiana University, USA.