There’s nothing like discovering a treasure trove of new evidence that helps piece together a prehistoric mystery — only to learn that everything that’s been found makes the discovery more mysterious.
A team of paleobotanists recently published an extensive study of Othniophyton elongatum, a 47-million-year-old “alien plant.” That’s the literal translation of Othniophyton. It’s literally unlike anything else anyone has discovered on the planet.
Researchers reconstructed the mysterious plant, from stem to flower, thanks to new specimens from multiple museums. They also reaffirmed that they have no idea what it is or where it fits into the flora family tree.
“We thought that having more features for identification would make it easier to place,” said Steven Manchester, curator of paleobotany at the Florida Museum of Natural History. “But it turned out not to be as easy as we thought it would be.”
Ivy Imitator
The alien plant has been an enigma since it was first discovered in the Green River Formation of eastern Utah. While the Green River Formation contains many alien-looking flora and fauna, including birds, salamanders and Sequoias, most can be linked to other living and extinct organisms, however distantly.
While Wyoming is world-renowned for its Green River deposits, the holotype of "the alien plant" was discovered near the ghost town of Rainbow in eastern Utah. If there is a Wyoming specimen of the plant, it hasn't been identified.
Manchester said one of the difficulties of studying this plant is that it isn’t especially common in the Green River Formation. Paleobotanists still struggle with identifying the “alien plant” because they don't have many fossils to work with.
“It’s relatively rare,” he said. “You can go banging on those shales and find a lot of fossil leaves, but this isn’t one of the common ones.”
Many prehistoric plants from the Green River Formation can be assigned to modern-day families, which made this plant's long, slender, and isolated leaves so baffling. Harry MacGinitie, a paleobotanist at the University of California, Berkeley, named the mysterious plant Oreopanax elongatum in 1969, placing it in the same family as modern-day ginseng and ivy.
That’s where it remained until Manchester looked through a collection of Green River fossils donated by a private collector to the University of California, Berkeley. The fossils had been collected from the same area in Utah as the original specimen, and Manchester had new information to share on the strange plant.
Small Discovery
Manchester rediscovered a tiny twig fossil in the newly donated collection. That twig answered many questions about the strange plant and raised many more.
“This twig had leaves and flower buds attached to it,” he said. “The flower buds themselves are helpful, but it still wasn't quite enough for me to feel like we understood it.”
Then, another specimen from the same spot emerged in the collections of the Denver Museum of Nature and Science. This specimen, found in Colorado, was another twig with attached leaves, fruits, flowers, and seeds.
Manchester said the first big revelation from the new specimens was that the leaves of the mysterious plant were situated as MacGinitie interpreted half a century ago.
“MacGinitie believes the elongated leaves were one part of radially arranged leaflets,” he said. “We found that the leaves were not in this radial arrangement but sprouted alternately on the twig.”
That observation proved the 47-million-year-old plant wasn’t in the same family as modern-day ginseng and ivy. The major breakthrough merited a new name for the mysterious, misidentified fossil.
However, further research didn’t provide many more answers. It only raised more questions.
Everything Leads To Nowhere
Thanks to the excellent preservation of the fossils, Manchester and the research team have learned a great deal about this plant. For instance, they know the shape of its flowers and can clearly see that its fleshy fruits contain 12 seeds each.
Ashley Hamersma, a graduate student and paleoartist involved in the study, even created a highly accurate reconstruction of the prehistoric plant. That makes it all the more incredible that there still isn’t enough information to determine where the plant fits into the plant family tree or its paleoenvironment.
“We're still kind of handicapped, even though we have a lot more information than we usually do,” Manchester said. “Paleobotanists deal with much older plants from families that are extinct today, but we can still make detailed comparisons to living plants.”
The Green River Formation preserves dozens of extinct plants with modern-day analogs. Based on the characteristics of their leaves, fruits, and flowers, prehistoric plants found in these rocks can be placed in modern-day families.
In this case, the researchers had multiple leaves, fruits, and flowers from the same type of plant – and they still couldn’t find a precise place to put it.
“We’re used to working with a single leaf or seed to assign a fossil to modern genera,” Manchester said. “We felt like we had enough characteristics of this plant to make detailed comparisons across living flowering plants, but it didn't seem to fit nicely into a modern category.”
Manchester said that a fossil harboring this much uncertainty despite a relative abundance of fossil evidence “isn’t typical” for paleobotanists, especially those studying the relatively recent plants from the Green River Formation.
“It's more typical that you can say a plant is from the oak, banana, or grape family when you have this many features,” he said. “I've done a lot of work on those families and others where these are the features you need to demonstrate that it's this family and it's not controversial. This one is a little strange.”
The only sure thing Manchester’s team could say is that the plant wasn’t in the same family MacGinitie had placed it in. That merited giving the strange plant a new name reflecting its strangeness: Othniophyton elongatum, “the elongated alien plant.”
“There are still things we don't know about it, but we know it isn’t what we thought it was,” he said. “We can’t trace ginseng back 50 million years through this plant, but we can’t say much more. I started this thinking of it as pretty esoteric, and it has been.”
Alien Explanation
Future research on “the alien plant” will depend on new discoveries, either in the field or on the dusty shelves of museums. Manchester wants to know precisely what kind of plant Othniophyton was and how it occupied its prehistoric world.
“I think it's reasonable to say it's not an herbaceous plant, so it’s either a shrub or a tree,” he said. “If I had to guess, I’d say it’s a tree. The stalks of the leaves are quite thick, which suggests that it was evergreen in subtropical forests, like the magnolia.”
With the leaves, fruits, and flowers accounted for, Manchester wants to find the plant’s pollen and bark. These would reveal more about its similarities to extinct and extant plants, possibly giving it a place in the multi-million-year history of plant evolution.
Answers could come from future excavations in the Green River deposits of Utah and Wyoming. They could also come from the other side of the globe, which Manchester finds potentially exciting.
“There's a lot of work going on in the Eocene deposits of Tibet,” he said. “My Chinese colleagues are collecting many fossils identical to what we find in the Green River Formation. They could find more specimens that reveal more information.”
Manchester admitted that the flurry of press attention around his alien plant “gathered more attention than expected,” but that has increased awareness in the paleontology community. Paleobotanists will search for more specimens of Othniophyton and examine the existing specimens from new perspectives.
“A good thing about publishing these studies is that these articles get spread internationally,” he said. “There's a chance that people in other places will recognize the same thing where they are. We can recognize fossils of the ginkgo living in China today, and they find fossils of Sequoias that live in California today.”
Of course, there’s always the possibility that this extinct alien plant isn’t as extinct or alien as we currently understand. There’s a chance Othniophyton has a modern-day descendent, and Manchester said he’d be happy to be proven wrong.
“So far as we can determine, this plant is extinct,” he said. “But now that we’ve put this out there, somebody could come along and say Othniophyton has features of this plant that we found living in Thailand today. As far as we know, this isn’t something still around today, but I'd be delighted to be shown that I'm wrong.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
