A recent discovery of 47-million-year-old fossilized plants from Utah’s Green River Formation has unveiled an extinct plant family, shedding new light on the history of flowering plants. The species, now named Othniophyton elongatum, is unlike anything alive today, revealing that the evolutionary history of plants may be far more complex than previously understood.
Initial Misclassification
The first fossils of this plant were discovered in 1969 and studied by paleobotanist Harry MacGinitie, who classified the species as Oreopanax elongatum under the ginseng family, based on similarities in leaf structure. MacGinitie believed the fossils were related to the modern Araliaceae family, which includes plants like ginseng, ivy, and angelica.
However, this classification was called into question following the discovery of additional fossils. “This fossil is rare in having the twig with attached fruits and leaves,” explained paleobotanist Steven Manchester of the Florida Museum of Natural History. “Usually those are found separately.”
Key Differences from Modern Plants
Closer examination of the new specimens revealed significant differences. Unlike the compound leaves of the ginseng family, the leaves of Othniophyton elongatum were directly attached to the twig. The attached berries also displayed an unusual characteristic: their stamens, the male part of the reproductive system, were still present even as the fruit matured.
“Normally, stamens will fall away as the fruit develops,” said Manchester. “And this thing seems unusual in that it’s retaining the stamens at the time it has mature fruits with seeds ready to disperse. We haven’t seen that in anything modern.”
A Unique and Extinct Lineage
The research team used advanced microscopy to analyze the fossils in greater detail. They studied the internal structure of the berries, seeds, and flowers, but could not match the plant to any known modern species or fossil record.
“We just don’t know where this plant sits in relation to other plants,” said the research team in their publication. While it showed some similarities to the Caryophyllales order, the differences were too significant to establish a link.
As a result, the plant was renamed Othniophyton elongatum—derived from the Greek for “elongated alien plant”—and classified as belonging to an extinct family.
Implications for Paleobotany
The findings challenge the assumption that all early flowering plants must be linked to existing families. “There are many things for which we have good evidence to put in a modern family or genus, but you can’t always shoehorn these things,” said Manchester.
The discovery opens new avenues for studying the evolution and extinction of plant species during the Cenozoic era, offering insights into how plants adapted—or failed to adapt—to changing conditions over millions of years.
The research shared by Science Alert was published in the Annals of Botany.
