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.

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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