Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.
Showing posts with label Isle of Skye. Show all posts
Showing posts with label Isle of Skye. Show all posts

Friday, April 11, 2025

Footprints in the sand

What comes to mind when you think about the Isle of Skye?

Chances are, it's one of three things.

The first is the stunningly beautiful scenery.  It's the largest of the Inner Hebrides, and is noted for its rugged, rocky hills, craggy coastline, and emerald-green meadows.

Sidney Richard Percy, Loch Coruisk (1874) [Image is in the Public Domain]

Second, history buffs will remember Skye as the place where "Bonnie Prince Charlie" (Charles Edward Stuart) fled, with the help of Flora MacDonald, after Scotland's devastating loss at the Battle of Culloden.  Stuart's repeated attempts afterward to claim the thrones of England and Scotland never came to much.  He died in exile in Rome in 1788 at the age of 67, depressed and miserable -- but even today, he remains a symbol to many Scots of "what might have been."

Third, if you're someone who likes to indulge in a wee dram on occasion, you probably know that it's home to the famous Talisker and Torabhaig distilleries, which produce absolutely fantastic single-malt whiskies.

I doubt, somehow, that many people would come up with a fourth thing that Skye should be famous for, and which was the subject of a paper in PLOS-One this week: it is one of the best sites for middle-Jurassic age fossils in the world.

167 million years ago, Scotland was about at the latitude of the Tropic of Cancer, and was a hot, lush swampy rainforest.  Prince Charles's Point -- the place where Bonnie Prince Charlie supposedly landed after making it safely "over the sea to Skye," in the words of the Skye Boat Song -- was a shallow, sandy-bottomed lagoon.

And it was home to some big dinosaurs.

The paper describes tracks by huge, long-necked sauropods like Cetiosaurus -- and those of the carnivorous theropods that hunted them, such as Megalosaurus.

A complete Cetiosaurus skeleton found near Rutland, England  [Image licensed under the Creative Commons Paul Stainthorp from United Kingdom, Cetiosaurus mount, CC BY-SA 2.0]

The Cetiosaurus tracks are as big around as car tires, and the study found individual trackways twelve meters long -- made, the researchers said, by dinosaurs ambling about, probably in search of the huge amounts of food it took to keep an animal that size going.

It's hard to imagine the rugged, windswept islands of the Hebrides like they were then -- something more like today's Florida Keys, and the home to the whole assemblage of mid-Mesozoic fauna.  Not only the big theropods and sauropods, such as the ones that left the footprints on the Isle of Skye, but pterodactyls flying overhead, and in the seas, the superficially dolphin-like icthyosaurs -- and the long-necked plesiosaurs that still come up in conversations about Loch Ness, only a hundred miles east as the Rhamphorhynchus flies.

"O Earth, what changes hast thou seen?" Tennyson mused -- "There, where the long road roars, has been the stillness of the central sea."  And those changes are still occurring.  The Atlantic Ocean is still progressively widening; a complex series of faults is making all of the Anatolian region twist counterclockwise; the "Horn of Africa" is rifting away from the rest of the continent and eventually will drift off into the Indian Ocean; Australia is on a collision course with Southeast Asia.  We humans leave our own footprints in the sand, but how ephemeral are they?  Will paleontologists 167 million years from now know of our presence, from traces left behind on whatever configuration the continents will then have?

It recalls the haunting lines from another poet, Percy Bysshe Shelley, which seems a fitting place to end:

I met a traveller from an antique land
Who said: Two vast and trunkless legs of stone
Stand in the desert.  Near them, on the sand,
Half sunk, a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things,
The hand that mocked them, and the heart that fed.
And on the pedestal these words appear:
"My name is Ozymandias, King of Kings:
Look on my works, ye Mighty, and despair!"
Nothing beside remains.  Round the decay
Of that colossal wreck, boundless and bare
The lone and level sands stretch far away.
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Wednesday, February 7, 2024

Wings over Skye

I know it seems like I keep ringing the changes on this topic over and over, but... it never fails to astonish me how much the Earth has changed over geologic history.

Part of my fascination, I think, comes from the fact that this knowledge is so at odds with how it feels to be an actual inhabitant of the planet.  When you look around, it seems like things are pretty static.  Oh, there are changes -- volcanoes and earthquakes come to mind -- but however catastrophic those can be for local residents, the fact remains that they are, on a planetary scale, tiny effects.  To see the big shifts requires a much longer time axis, but if you have the perspective of one...

... wow.

Take, for example, the discovery of new species of pterosaur in one of the last places I can picture a pterosaur flying -- the Isle of Skye, Scotland.  Now a cool, windswept, rocky island chain with few trees and lots of grass and heather, the Hebrides (and the rest of the British Isles) were, during the Jurassic Period, a lush subtropical land only separated from what would become North America and Greenland by a shallow strait of ocean.

The configuration of the continents at the mid-Jurassic [Image credit: Ron Blakey, NAU Geology]

And flying over the forests of Jurassic Scotland were some of the coolest prehistoric beasts ever, the pterosaurs.

Dubbed Ceoptera evansae -- the genus name means "mist flyer," from the Gaelic word ceò, mist, which also gives the Isle of Skye its Gaelic name of Eilean a'Cheò, "misty island" -- the newly-discovered fossil was found in the Kilmaluag Formation and dated to about 167 million years of age.  Ceoptera was a smallish pterosaur, measuring about sixty centimeters from beak to tail tip:

[Image credit: Elizabeth Martin-Silverstone et al., Journal of Vertebrate Paleontology]

The era when Ceoptera was flying over the Isle of Skye was a point of great diversification amongst the pterosaurs, a process which would accelerate during the rest of the Jurassic and into the Cretaceous, ultimately resulting in species from fifty-centimeter-long Sordes pilosus to the six-meter-wingspan Quetzalcoatlus northropi.  Eventually, however, the entire taxon would be wiped out in the Cretaceous-Tertiary Extinction of sixty-six million years ago.

"The time period that Ceoptera is from is one of the most important periods of pterosaur evolution, and is also one in which we have some of the fewest specimens, indicating its significance," said Elizabeth Martin-Silverstone of the University of Bristol, who led the study, in an interview with Science Daily.  "To find that there were more bones embedded within the rock, some of which were integral in identifying what kind of pterosaur Ceoptera is, made this an even better find than initially thought.  It brings us one step closer to understanding where and when the more advanced pterosaurs evolved."

For me, the coolest part is trying to picture what the world looked like back then.  Even with our knowledge of plate tectonics and the fossils we have available for study, we still have only the shadowiest image of the Jurassic world.  Consider what doesn't fossilize -- colors, sounds, smells, behavior.  We can make some guesses about what those were like based upon modern organisms, but guesses they will always be, and many of them significantly off the mark.  (If you want a good laugh some time, look into "prehistoric animals that were reconstructed wrong" and find out how wildly inaccurate even the experts can be.  Fortunately, science self-corrects, and the fact that we now know they were wrong comes from better fossils and more sophisticated analysis -- but even so, we still have a vague and incomplete picture of what things were really like back then.  Oh, for a time machine...)

So that's our flight of fancy for today.  Prehistoric wings over the Isle of Skye.  Makes you wonder what things will look like in another 160 million years or so.  We'll have a whole new set of "endless forms most beautiful and most wonderful," to use Darwin's trenchant words -- ones we could not even begin to predict.

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