GHOST RIVER - Here and there on an exposed rock outcrop just above the treeline in the Ghost River region about an hour east of Cochrane, a tinge of red might catch your eye.
It might not look like much from a distance, but these high outcrops may represent one of the best chances to understand the earliest evolution of plants as we have come to know them today.
Called the Yahatinda formation, the rocks date back to about 385 million years ago to the heart of the middle Devonian age. It was a time long before the rise of dinosaurs, when the world was essentially one giant waterworld with two solitary landmasses comprised of what would eventually become the modern continents sitting in the middle of it.
At the beginning of this era in history, the vast majority of life, both plant and animal based, thrived within and beneath this vast ocean. But at some point, that all began to change.
It began to change with the emergence of the first ever land based plants about 468 million years ago – ancient relatives of those we know today in forms we likely would not even recognize. These plants photosynthesized, but they did not produce leaves, cones, or seeds. Instead, these stick-like plants spread themselves through spores released into the atmosphere.
At some point, Devonian plants began to evolve into forms that did bear cones and seeds, and by the end of the Devonian Age, vast forests of still alien trees and plants – but more recognizable with modern equivalents – covered the land, creating the first ecosystem of green on the face of the earth.
“This period of geological time about 388 to 383 million years, the Yahatinda is right in the middle of that,” explained Dr. Az (Ashley) Klymiuk, a paleobotanist who currently teaches at the University of Manitoba as an Indigenous Scholar in Science with the university’s Department of Biological Sciences.
“At this period of time, the planet is undergoing this massive change. We call it aforestation, or the rise of global forests. This has impacts for global climate, how nutrient cycling works, and the developing and enrichening of soils. And at the same time this is all going on, we have the evolution of seeds.”
What makes the Yahatinda special, according to Dr. Az, is that the formation is a remnant of the ancient river beds that once ran into a shallow marine basin on the edge of the sea. But those rivers originated inland, and brought with them debris from land based plants.
Thus, it represents, potentially, a treasure trove of fossilized knowledge about what those earliest land-based plants would have looked like, and may even preserve their cellular structure in the fossil record.
“So that means we can see the cellular anatomy,” confirmed Dr. Az. “Cellular anatomy tells us a lot more about plant growth than and development than smooshed axies (fossils) on a rock.”
The potential of the Yahatinda formation has been known for many decades, since famed American paleontologist Charles Walcott first noted many features of the Yahatinda in the early 20th century in channels cut through his Cambrian era rocks. Walcott is credited as the first researcher to reveal the secrets of the Burgess Shale fossil site, which recorded some the earliest forms of life on Earth in the in the Cambrian period 508 million years ago.
However, what impeded deeper exploration of the Yahatinda over the past 100 years is the same thing that impedes deeper exploration still today; the difficulty of accessing such rough terrain.
Keith Mychaluk, who serves as a field trip coordinator for the Alberta Paleontologicial Society (APS), took part in one of very few scientific explorations undertaken up to these high rocks in recent decades. He, alongside other members of the APS and members of the Canadian Geological Survey, ascended together to specifically seek out Yahatinda outcroppings in 2000.
It was a memorable trip, recalled Mychaluk, particularly because of how arduous the journey to get there was.
“It’s extremely difficult road access to begin with, but that doesn’t stop a lot of people getting in there. Whether you are a fisherman or ATV enthusiast, or whatever, that part can be surmounted,” he explained.
“But from there, there are no trails to where you want to go and this particular formation is only exposed at higher altitude, usually just above treeline.”
Mychaluk’s expedition travelled from Cochrane out to the Forestry Trunk Road to Waiparous Creek area, and then west toward the Ghost River headwaters near the eastern end of Lake Minnewanka. After that, it was hard climbing on foot.
“Without any obvious trail access, even animal trail access, it’s almost just bushwacking straight up,” Mychaluk recalled.
Mychaluk does not recommend anyone undertake the trip without a proper four-wheel drive vehicle, proper equipment, a solid plan and a knowledgeable guide.
And even if you make your way up to one of the sporadic formations spread out along the edges of the mountains here and there, you might now know what you are looking at anyway, without some strong grounding in geology or paleontology, he added.
“It is still difficult to figure out what layer you want to focus on,” said Mychaluk. “There is no ‘X marks the spot.'”
Mychaluk said he and his team of experienced fossil hunters did find an outcrop of Yahatinda formation on their 2000 excursion, but the fossil samples were not what some might expect.
“On that trip, I think we were extremely happy as a group to find an outcrop of this particular formation,” he said. “We certainly found nothing of show quality, but we did find some (fossilized) Devonian age plant debris.”
Those types of debris fossils are pretty typical for the Yahatinda, agreed Dr. Az. There have been a few decent full fossil samples derived from the Yahatinda over the years, the professor explained, but as the Yahatinda was the bed of an ancient river system, it tended to break down plants to their component parts as it rushed on its way toward that ancient sea – much like modern rivers do today.
“You don’t get (many) plant body fossils in there,” Dr. Az said. “You get carbon-rich, dark-stained areas of the rock, but you don’t get plant fossils.”
But because the Yahatinda represents a vast collection of plant debris and parts, Dr. Az feels the formation could be a bounty of potential information about the nuts and bolts of early plant development.
The professor, in fact, is enormously excited about the potential for finding cellular and physical structures in these Devonian fossil beds. This may provide a missing link in paleobotany that many have been seeking for a long time: evidence of the anatomy of the first ever seed-bearing plants.
The earliest seed-producing plant known at present is Elkinsia polymorpha, which is a Late Devonian fossil discovered in Elkins, West Virginia dating between 280 and 345 million years ago.
Anything that might be a seed-plant that turns up in the Yahatinda would be significantly older and would push the origin of seed-plants farther back in time.
That would be a big deal, according to Dr. Az.
“We don’t really understand the whole diversity of seed-bearing plants, and which group of plants they evolved from,” the professor said. “So this is where the Yahatinda formation becomes really interesting.”
Given its general inaccessibility and the relative lack of museum-quality fossils found in the Yahatinda during the past century, not a lot of concentrated research effort or dollars have been spent on field studies of the formation.
Dr. Az is hoping to fund a potential future helicopter exploration of some key sites, but the research team would need to scout out a good target ahead of time.
“People who are constantly out on the land have a better understanding of where things are, and they have seen more things than any research scientist has time to ever explore, or ever understand,” Dr. Az stated. “The more we know about where there might be good deposits, the more precision point we can be with our explorations and collections.”
Mychaluk concurred, but added there is another reason to consider a deeper exploration of the Yahatinda – sheer scientific curiosity and wonder.
“Sometimes you get lost in the details, and you don’t see forest through the trees,” he said. “Those little specks of plant debris predate the first birds, they predate dinosaurs, they predate mammals … Never mind human history.
“None of us would have climbed up there unless scientists and adventurers 100 years before us hadn’t done some work. That’s one of the wonders of science and exploration, to build off of what others have done before you.
“So perhaps this...will encourage others to relook at what science has been done, and how much more could be done (in the Yahatinda).”
