Fifty-five years ago, a strange-looking fossil plant was discovered in Utah, near a ghost town, by paleontologists. Nicknamed Othniophyton elongatum (or foreign plant), this discovery initially intrigued scientists who thought that this fossil plant could be related to ginseng. However, recent research challenges this hypothesis and adds new mystery to this already enigmatic plant. Indeed, the new analyzes revealed that this plant does not seem to belong to any current or even extinct plant family, which confronts researchers with a fascinating question: Does Othniophyton belong to a completely unknown plant family?
The initial discovery: an enigmatic fossil
It all started in 1969, when paleontologists came across fossilized leaves of the plante Othniophyton elongatumin the Green River Formation of eastern Utah, near the ancient town of Rainbow. The region, which was home to a vast lake ecosystem ago about 47 million yearsallowed for exceptional preservation of fossils. Thanks to lake sediments and volcanic ash, many species, including fish, reptiles, birds and plants, have been preserved in remarkable condition.
The first discoveries of this plant were limited to fossilized leaves and based on the structure of the leaf veins, paleontologists of the time hypothesized that Othniophyton could be related to ginseng. This idea was plausible, because the shape of the leaves indeed seemed similar to those of plants in the ginseng family, known for its medicinal properties. However, this hypothesis remained incomplete, because the analysis did not take into account other aspects of the plant, such as its flowers and fruits.
A modern revaluation and clues that change everything
In 2021, Steven Manchester, curator of paleobotany at the Florida Museum of Natural History, made a significant discovery. During a visit to the University of California, Berkeley, he found a well-preserved plant fossil that came from the same region as the specimens originally discovered. Closer examination of this fossil, which includes flowers and fruit, allows researchers to completely revise their understanding of the plant.
This new analysis reveals that its characteristics do not correspond to those of ginsengbut rather present unexpected features. Indeed, the fossil flowers, fruits and leaves seem very different from anything we know from current or ancient plants.
Likewise, fossils show a special arrangement of stamensthe male reproductive organs of flowers. This detail struck the researchers: unlike the majority of plants which lose their stamens once fertilization is complete and the fruits begin to form, this plant seems to retain its stamens until the fruits are ripe and the seeds preparing to disperse. This phenomenon has never been observed in any modern plant species, which further adds to the strange nature of this discovery.
After comparing these fossils to more than 400 families of existing flowering plants, the researchers had to admit that they found no matches. In other words, after several decades of research, the conclusion is striking: Othniophyton elongatum appears to be an isolated plant which does not find a place in the current classification of plants. This raises questions about the evolution of plants and the biological diversity that existed in the past.
A new approach thanks to modern technologies
One of the reasons this discovery was possible is the use of modern technologies, such as advanced microscopy and artificial intelligence. These tools allow fossils to be observed at a level of detail previously unimaginable. For example, microprints of small developing seeds have been identified in fossil fruits, revealing information about the plant's reproductive cycle. In addition, artificial intelligence made it possible to examine the specimens with a precision that made it possible to detect elements invisible to the naked eye such as the presence of stamens on the flowers.
These new technologies have been a turning point in the analysis of fossils and open new avenues for the study of prehistoric plants and ancient ecosystems. The research team from the Florida Museum of Natural History also had access to more precise data thanks to artificial intelligence which made it possible to broaden the comparison with other plant fossils discovered in the same region. This technological advance has therefore made it possible to better understand the exceptional characteristics of this fossil plant.
