Glossopteris

Do you ever think about geologic time?

I do. The Earth is a staggering four and a half billion years old. Scientists divide that vast amount of time into different eras based on rock records—that’s geologic time. You’ve probably heard of the Triassic, Jurassic, and Cretaceous thanks to their most famous denizens, the dinosaurs. More specifically, those three are periods. Geologic time has increasingly shorter units of eons, eras, periods, epochs, &c. Periods are millions to tens of millions of years long—all told, the dinos spent about 150 million years on our planet. Today we live in the Quaternary period, and, more granularly, in the Anthropocene epoch¹, which spans the past 10,000-odd years. I really cannot overemphasize that 10,000 years is absolutely nothing when thinking on scales of geologic time. And yet, even within that “small” timespan, Robert Falcon Scott’s death on the Great Ice Barrier in 1912 was just a blink of an eye before the present day. Tantalisingly close or immensely distant…it’s all a matter of perspective, isn’t it?

The funny thing about geologic time is that the Earth’s activity makes it really hard to actually read the rock record. Our habitable planet is violently in motion; we have atmosphere and magma and this stuff called life everywhere, and new rocks are forming, yes, but they’re also breaking. Between all the earthquakes, tectonic plates subducting, volcanoes, erosion, and weathering, there’s no one place on Earth with a complete rock record. Instead, it’s pieced together bit by bit from evidence in disparate locations. One benefit of all that pesky life growing up around the rocks is that sometimes, if the conditions are right, remains of life get stuck—preserved—when new rocks are formed. These are fossils, and when considered alongside the rocks they are preserved in, they allow us to learn about creatures we otherwise would have never known existed—creatures that lived on Earth in other geological eras, epochs, or periods. Fossils can bridge the gulf of eons (literally, as in the unit of geologic time!)

Picture a scene. It’s 250 or 300 million years before the present day. The Permian period. The continents have been squished and rearranged in a different form than we’d recognise, as the Earth has slowly mashed them together and apart like play-doh. Just now, a lot of them are together. What will become modern-day Africa, South America, Australia, Arabia, India, and Antarctica form one huge landmass called Gondwana. And growing all over this vast supercontinent is a genus of trees with tongue-shaped leaves called Glossopteris: from the Greek for “tongue” and “fern”. These form the mighty forests of Gondwana, blanketing much of the Earth’s land area millions of years before the first dinosaurs. There are so many Glossopteris plants that they leave a strong imprint on the fossil record. They quite literally make their mark, which is just as well, because the Permian period is destined to end with a mass extinction event—the worst the Earth has ever known. All the Glossopteris plants will die out.

Fast forward to the 1800s. Geologist Eduard Suess concludes, from the presence of Glossopteris fossils on several different continents, that those continents must once have been connected. It is therefore a question of great scientific interest whether fossils of this extinct plant might be found in Antarctica—could it, too, have once been connected to warmer climes?

Now scooch just a little further forward on the timeline to February 8, 1912, where we find Robert Falcon Scott and his team limping back from the South Pole. They faced a hard fight to reach their goal, only to find Amundsen had been there first. Now, they’ve just descended out of reach of the hellish winds of the Polar Plateau and are traversing down the Beardmore Glacier. All five men are exhausted and malnourished, with Edgar Evans in particularly rough shape².

With his men badly in need of a break, Scott orders a working rest as the party passes a site of geological interest they had noted on the outward journey. Though no geologists are among the polar party, the polar party have been provided substantial notes of what they ought to be looking for should they come across any such interesting geological sites—and so, Scott and his men follow those instructions and “geologise” at a weathering cliff and glacial moraine. In what is one of the last relatively upbeat entries of his final diary, Scott describes enjoying the sun and the feel of rock under his feet after the weary march. The fossil specimens they uncover are clearly a source of particular delight.

Without further ado, the first of what will surely be many extensive quotes from Scott’s diary³ on this blog:

We decided to steer for the moraine under Mt. Buckley and, pulling with crampons, we crossed some very irregular steep slopes with big crevasses and slid down towards the rocks. The moraine was obviously so interesting that when we had advanced some miles and got out of the wind, I decided to camp and spend the rest of the day geologising. It has been extremely interesting. We found ourselves under perpendicular cliffs of Beacon sandstone, weathering rapidly and carrying veritable coal seams. From the last Wilson, with his sharp eyes, has picked several plant impressions, the last a piece of coal with beautifully traced leaves in layers, also some excellently preserved impressions of thick stems, showing cellular structure. In one place we saw the cast of small waves on the sand. To-night Bill has got a specimen of limestone with archeo-cyathus—the trouble is one cannot imagine where the stone comes from; it is evidently rare, as few specimens occur in the moraine. There is a good deal of pure white quartz. Altogether we have had a most interesting afternoon, and the relief of being out of the wind and in a warmer temperature is inexpressible. I hope and trust we shall all buck up again now that the conditions are more favourable. We have been in shadow all the afternoon, but the sun has just reached us, a little obscured by night haze. A lot could be written on the delight of setting foot on rock after 14 weeks of snow and ice and nearly 7 out of sight of aught else. It is like going ashore after a sea voyage.

Scott’s Last Expedition, entry for Thursday, February 8, 1912

How odd must it have been to find imprints of leaves in this barren place? Though Scott was surely unimaginably tired while writing, still his sense of wonder (and Wilson’s) shines through. Scott and his team could not identify the particular species of leaves they had found, but they recognised the scientific import of their finds and endeavoured to bring them back to someone who could, thus adding 35 lbs of these fossil-bearing rocks to their sledge. They would drag them to the last.

Nine months later, when the bodies of the polar party were found, the fossils were still strapped to their sledge.

Amidst their grief, the surviving expedition members followed this clear request of the dead Scott, Wilson, and Bowers to take the fossil specimins back to Britain. There, it was discovered that among them were fossils of Glossopteris, proving Antarctica was once connected to other continents, and trees not dissimilar from modern beech trees had grown there. While earlier expeditions had also found Antarctic fossils, none constituted such a momentous discovery as the polar party’s Glossopteris, owing to the age and extinct status of the genus.

More than 250 million years ago, a Glossopteris tree died in Antarctica. Time transformed the land and rendered it inhospitable to such flora, but just over a century ago five men, themselves visitors from warmer climes, would find this trace of a tree and recognise it—just before the land proved inhospitable to them, as well.

The point of this article is not to bore you about geologic time, but, as you’ve certainly clocked, to explain my choice of a blog title. The Glossopteris story was one of the first that really gripped me about polar history, and, if you’ll forgive my waxing poetic, I think it’s because there’s a deeper echo to it. To me, there’s something intangible and cyclical and poignant about these haggard, driven men finding preserved leaves from hundreds of millions of years previous, leaves of a species that died out in the worst disaster Earth life has ever known, while facing disaster themselves. Geological time marches on, as the Earth constantly reshapes itself. Scott and his men are, of course, still down there, buried within the heart of the Ross Ice Shelf. Preserved. Perhaps not fossils scientifically, but in some other sense I’d argue they are. They joined the landscape, and it slows their decay. If I may extend the metaphor from their bodies to their records: they left traces that reach far beyond their own time, documents we can study…but just as that dead leaf will never speak to the whole tree, neither can every document I could possibly read about these men speak to their whole selves. The gulf of a century is too wide, let alone the gulf of 250 millions years they were trying to bridge. Glossopteris reminds me that some of the past will always be lost, try as we might. But equally, isn’t it amazing we can learn of it at all? What flaps of a butterfly’s wing has it taken for any of this information to reach us⁴? For the leaf to become preserved in the rock? Though things will be lost, doesn’t that make it all the more important to try, as Scott and his men did? I think so.

So why did they do it? Why did they stop to geologise when they were in dire straits, why did they add extra weight to their sledges that wasn’t helping feed them or keep them warm? It’s certainly a decision of Scott’s that many have criticised, and I can understand why. Others have countered that it is a testament to the true scientific goals of the Terra Nova expedition, which certainly was about more than just pole-bagging. For what it’s worth, I don’t think the extra few hours not marched or the extra bit of weight pulled killed them. But regardless, for the sake of this post, I’m not interested in playing the what-if game. What matters is that, unequivocably, these fossils were important to them, and I find that interesting. Inspiring, even, if obviously tinged with tragedy. I derive something Frankensteinian, something of Burke’s definition of the sublime, from thinking about those Glossopteris fossils. Tantalisingly close or immensely distant…

I don’t pretend this blog will approach anything near the excessive meaning I and others have heaped upon these fossils. But “Glossopteris” is unique, provides a good story to relay when introducing this blog to people, and is a topic I’m happy to be reminded of consistently and keeping thinking about.

Oh, and there’s one more reason….one I find a bit haunting in hindsight. During Scott’s first expedition, on Discovery, there was a shipboard newspaper founded called the South Polar Times. Contributors wrote under pseudonyms. Scott’s first article was a parody one on “horticultural notes” of their new environs, speaking of ice flowers and such. Do you want to know Scott’s pseudonym on this very first article?

He signed it Glossopteris flora.

1. Still under proposal as an epoch. ↩︎
2. He would die nine days later ↩︎
3. Scott’s Last Expedition is in the public domain and can be read here on Project Gutenberg. ↩︎
4. When speaking of the historical record, there is of course a fair amount of human will and bias mixed in with the chance. That’s a topic for another post, perhaps. ↩︎