Scary times

Dear Readers:

This is to let you know of some upcoming changes.

Some of you might know I also write over at Substack, and over there have focused mainly on writing, fiction, storytelling, and how stories and mythology have woven their way through history.  I've noticed that in the last year or two, this site (and Blogger in general) has been swamped with bots and AI scrapers, and I think it's time to switch platforms, and only write through Substack.

I welcome you all to subscribe to my site at the link above (for free!).  The plan is on Mondays and Thursdays, I'll focus on stories, storytelling, and language, and on Tuesdays and Fridays I'll write the science news and critical thinking posts you've found here at Skeptophilia.  Wednesdays and Saturdays will be anyone's guess!  Sometimes one, sometimes the other, sometimes wherever my chaotic brain takes me.

At some point I'll be offering in addition some paid-subscriber-only content, like audio chapters from one of my books, some quick video mini-lessons on a topic in critical thinking, or something else fun and extra.  But for now, everything's free for everyone.

If you've been accessing Skeptophilia through social media (Facebook or Bluesky), no worries -- I'll still be posting links there, so you don't have to do anything different.  The links will look a bit different, but that's the only change.

This week, I'll have Tuesday's and Friday's posts in both places, but Friday will be the last post here at Skeptophilia.  Starting next week, I'll only be posting to Substack.  However, my old Skeptophilia posts will still be available here to browse through!

I hope you'll join me over there, subscribe, and continue to comment and interact!

I've been at this for sixteen years -- thanks for the encouragement that keeps me going.

Best,

Gordon

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It's an interesting question to consider how long a human life expectancy would be if we had a time machine (or, as my friend Andrew Butters would correct me, a space-time machine).

There are all the possibilities during recorded history, some of which would be dramatically worse than others (depending, of course, on exactly where you decided to go).  Southeastern Europe in the mid-fifth century would be a poor choice, given the fact that Attila the Hun was kind of trampling the place, causing chaos amongst the Goths (who were already there) and the Romans (who wished the whole lot of them would just go away).  Just about anywhere and any time, of course, would have been worse if you were poor; the "nasty, poor, brutish, and short" quip about people's lives in the past is all too accurate, and worse still if you didn't have privilege (a condition that sadly hasn't changed much).

But if you could add in prehistoric times, there are choices that would be a great deal worse than any time in recorded history.  And that's even assuming you're eliminating periods prior to the Great Oxidation Event, when the Earth's atmosphere would have killed you rapidly if you didn't think to bring along an oxygen supply.  Likewise, let's put out of the running the Late Ordovician (Hirnantian) Glaciation Event, when damn near the entire Earth was covered in glacial ice, and events like the Chicxulub Meteorite Collision.  Hard to imagine how we could survive either one of those.

One time period that often comes up in these discussions is the Carboniferous.  This was the era of the enormous arthropods -- dragonflies like Meganeura with its 75-centimeter wingspan, and the two-meter-long millipede Arthropleura -- which are thought to have evolved because of the favorable conditions of warmth, moisture, and an oxygen concentration in the atmosphere that may have exceeded thirty percent.  But honestly, there's no certainty these things would have been all that dangerous to something the size of a human; so other than the "ooh, icky, creepy-crawlies with lots of legs" issue, the Carboniferous would probably not have been all that bad.

For my money, the odds-on winner is the mid- to late-Cretaceous.  Not, perhaps, for the reason you're thinking; that period of Earth's (pre)history always brings to mind the Tyrannosaurus rex and the Velociraptor, which were certainly scary beasts.  But they are far from the only thing you'd have to worry about, should your space-time machine drop you off there.

I wrote just last month about the Kem Kem Formation in Morocco, a shale and limestone deposit formed when that part of the world was a shallow ocean, and what is now the Sahara was a tropical rain forest.  This place was, to put not too fine a point on it, a fucking nightmare.  It was home to the schoolbus-sized theropod Carcharadontosaurus, which had twenty-centimeter teeth serrated like steak knives; twenty-meter long crocodilians like Aegisuchus; and the pterodactyloid Apatorhamphus, with a five-meter wingspan and dozens of needle-sharp teeth.

Carcharodontosaurus skull [Image licensed under the Creative Commons Matthew Deery, Ultimate Dinosaurs Carcharodontosaurus, CC BY 2.0]

Oh, so don't head to Morocco, then!  We'd be fine!  Right?

Not really.  The region bordering the  Western Interior Seaway, which bisected North America from north to south during the same time period (and is why Montana, the Dakotas, Nebraska, and Kansas are such great places to find fossils), was no better.  There was a horrific fish called Xiphactinus that was five meters long.  The Seaway was also home to mosasaurs, carnivorous reptiles that could get to be over twice that length.  The plesiosaurs, whose shape will be familiar to aficionados of the Loch Ness Monster, were longer still.

If you were to visit the Cretaceous, going for a nice skinnydip would not be recommended.

Xiphactinus skeleton [Image licensed under the Creative Commons Jonathan Chen, Xiphactinus AMNH, CC BY-SA 4.0]

The reason this stuff all comes up is a rather ghastly set of fossils from that time period that was the subject of a paper in Nature this week.  A group of paleontologists, let by Jongyoon Jung of the University of Texas - Austin, discovered sets of tracks at a Cretaceous-age site in South Korea.  One of the sets has been analyzed and found to come from an azhdarchid pterosaur that is new to science.  The team named it Jinjuichnus procerus, and from its tracks they've concluded that (1) it seems to have come down to the ground to hunt, (2) walked on its knuckles while it was doing so, and (3) had an eight-meter wingspan.  If that's not bad enough, there's a second set of tracks, from an unidentified small terrestrial vertebrate.  The two sets of tracks intersect, and there's a confused mess of marks at their intersection.

Guess what that means.

If our imaginations weren't bad enough, the scientists have kindly provided us with the following artist's rendition of the event:

[Image credit: artist Jun Seung Yi, Creative Commons CC BY 4.0 License]

Just in case you needed some more fuel for your dreams tonight.

So.  Yeah.  Dinosaur enthusiast though I am, I would not jump at the chance for a trip back to the Cretaceous.  In fact, considering what I know about most of Earth's geological time periods, I think I'll stay put right here where there are not many creatures with Big Nasty Pointy Teeth, and there are nice features like modern medicine, water purification systems, and indoor plumbing.

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Lost and found

I'm currently reading Michael Novacek's fascinating book Dinosaurs of the Flaming Cliffs, which is about the expeditions led by Novacek into the backcountry of the Mongolian Gobi Desert in search of late Cretaceous dinosaur fossils.

And they found 'em.  In abundance.  The remains that Novacek's team unearthed changed our understanding of the evolution of dinosaurs and early mammals in central Asia -- I've already lost count of the number of new species his group found, and I'm only about a third of the way through the book.

What struck me, though, is the combination of physical and personal hardship that the team members were willing to tolerate to achieve their goals.  The Gobi Desert is, even today, largely untraveled and unmapped; the nomadic groups that live in its arid wastes have to keep moving to survive in a climate that is broiling hot in the summer and viciously cold in the winter, has little in the way of drinkable fresh water, and is thin pasturage for domestic animals even at the best of times.  These scientists launched into the arid badlands in old, Soviet-era trucks that broke down every time someone sneezed hard, with carefully-rationed food, water, and gasoline, and exactly zero margin for error.

The fact that they not only survived, but achieved their scientific goals (and then some), is downright astonishing.  And every other page, I've shaken my head and thought, "I would never have the courage to do something like this.  Not in a million years."

Keep in mind, too, that this is coming from someone who did his share of backcountry camping, mostly in the Cascades and Olympics of Washington State.  Being a teacher has its perks -- June, July, and August being top of the list -- and when I was in my twenties I frequently disappeared into the fir-shrouded forests during the summer for weeks at a time.  So I'm no stranger to sleeping outdoors and hiking with a heavy pack.  (Or at least I was.  Now that I am Of A Certain Age, I'm afraid my appreciation of the creature comforts has done nothing but increase.)

But still: I would never have been brave enough to take off into the wilds of Mongolia the way Novacek et al. did (repeatedly).  Which probably would have scotched any intent I might have had to become a paleontologist.

On the other hand, sometimes -- admittedly, it's probably rare -- great paleontological discoveries can come from merely opening the right drawer in a museum.  The reason the topic comes up (besides my current reading-in-progress) is the chance find by paleontologist Georgios Georgalis of the Institute of Systematics and Evolution of Animals of the Polish Academy of Sciences in Krakow, who was doing some research in London's Natural History Museum and stumbled across the bones of a very unusual fossil snake that had been overlooked for forty years.

Dubbed Paradoxophidion richardoweni -- "Richard Owen's paradoxical snake" -- it lived in England during the Eocene Epoch, something like 37 million years ago.  At that point, England was a great deal warmer than it is now.  The world was just exiting the Paleocene-Eocene Thermal Maximum, at eight degrees Celsius higher than today one of the highest global average temperatures ever recorded.  The hot times favored diversification of ectothermic animals -- such as snakes -- in what are now regions with much cooler climates.

"It was my childhood dream to be able to visit the Natural History Museum, let alone do research there," said study lead author Georgalis.  "So, when I saw these very weird vertebrae in the collection and knew that they were something new, it was a fantastic feeling.  It's especially exciting to have described an early diverging caenophidian snake, as there's not that much evidence about how they emerged. Paradoxophidion brings us closer to understanding how this happened."

The snake species, Georgalis said, seems to be related to a group called acrochordids now found only in southeast Asia and Australia -- although more study is needed to be certain.  And it also brought up the tantalizing question of what else might be hiding in museum drawers and cabinets.

"I'm planning to study a variety of snake fossils in the collection, including those originally studied by Richard Owen" Georgalis said.  "These include the remains of the giant aquatic snake Palaeophis, which were first found in England in the nineteenth century.  There are also several bones with differing morphology that haven't been investigated before that I'm interested in looking at.  These might represent new taxa and offer additional clues about snake evolution."

So I guess you don't need to endure sandstorms and blistering heat and terrible food to make significant contributions to the field.

This also highlights the critical importance of museums in the entire scientific enterprise.  I found out yesterday the amazing news that one of our best local museums, the Paleontological Research Institution/Museum of the Earth, has received enough donations to remain open -- funding cuts were looking likely to shutter it permanently.  On the one hand, I'm thrilled that enough people were willing to donate to keep this wonderful place going (and if you're willing, I encourage you to go to their website and do so as well -- even if they met their goal, they can still put every penny to good use).  On the other, though, isn't it sad that we never seem to run out of money for stuff like funding war and paying kickbacks to corporate billionaires, but cutting-edge scientific establishments that are inspirations to thousands basically have to hold a bake sale to stay in business?

[Image licensed under the Creative Commons Matt Wedel, Yale brontosaurus, CC BY 4.0]

In any case, here's another puzzle piece adding to the picture of what the Earth was like tens of millions of years ago, that had been hidden away in a museum cabinet for four decades.  I find the whole thing endlessly fascinating, which probably explains why the topic of paleontology is such a frequent flier here at Skeptophilia. 

But as interested as I am, I still don't think I'd be brave enough to venture into the Gobi Desert to study it.

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Strange bedfellows

There's a Senegalese expression that goes, "There are forty kinds of lunacy, but only one kind of common sense."

The outcome of this general principle is that trying to support pseudoscientific claims sometimes forces alliances between groups you'd never think would have anything in common -- such as the cryptozoologists and the young-Earth creationists teaming up to find evidence of the "Mokèlé-Mbèmbé," a water-dwelling beastie that supposedly lives in the Congo River Basin.

The first written account of the Mokèlé-Mbèmbé seems to be from science writer (and cryptozoology buff) Willy Ley in his 1941 book The Lungfish and the Unicorn, but his description was (he said) taken from an unpublished report written by German military officer and explorer Ludwig Freiherr von Stein zu Lausnitz, who was summarizing sightings by natives he'd spoken to in Cameroon.  Here's what Ley had to say:

The animal is said to be of a brownish-gray color with a smooth skin, its size is approximately that of an elephant; at least that of a hippopotamus.  It is said to have a long and very flexible neck and only one tooth but a very long one; some say it is a horn.  A few spoke about a long, muscular tail like that of an alligator.  Canoes coming near it are said to be doomed; the animal is said to attack the vessels at once and to kill the crews but without eating the bodies.  The creature is said to live in the caves that have been washed out by the river in the clay of its shores at sharp bends.  It is said to climb the shores even at daytime in search of food; its diet is said to be entirely vegetable.  This feature disagrees with a possible explanation as a myth.  The preferred plant was shown to me, it is a kind of liana with large white blossoms, with a milky sap and apple-like fruits.  At the Ssombo River I was shown a path said to have been made by this animal in order to get at its food.  The path was fresh and there were plants of the described type nearby.  But since there were too many tracks of elephants, hippos, and other large mammals it was impossible to make out a particular spoor with any amount of certainty.

So already we're talking about a third-hand account; Ley recounting what he'd read that von Stein had written about what natives told him.  Ley also quotes one Lieutenant Paul Gratz, who is not a lot more convincing:

The crocodile is found only in very isolated specimens in Lake Bangweulu, except in the mouths of the large rivers at the north.  In the swamp lives the Nsanga, much feared by the natives, a degenerate saurian which one might well confuse with the crocodile were it not that its skin has no scales and its toes are armed with claws.  I did not succeed in shooting a Nsanga, but on the island of Mbawala I came by some strips of its skin.

Ley says that the Mokèlé-Mbèmbé and the Nsanga are the same, which I guess is true because it's very likely that neither one is real.  Skeptic Donald Prothero dismisses alleged sightings of the Mokèlé-Mbèmbé as being either crocodiles, black rhinos, or simply overactive imaginations, and I'm inclined to agree with him.  The only alleged photograph of the beast, taken by explorer Rory Nugent in 1985, is almost certainly a distant snapshot of a floating log.

A sketch of a Mokèlé-Mbèmbé, which I have to admit looks nothing like either a crocodile or a rhino, but does appear to have been heavily influenced by watching The Land Before Time [Image is in the Public Domain]

So the whole thing would be in the same category as Bigfoot and Nessie and Mothman et al. -- but then the creationists got involved.

Scottish explorer and young-Earth creationist William Gibson funded and led two expeditions into the Congo River Basin to try to prove the Mokèlé-Mbèmbé exists, although how this would support creationism is beyond me.  Maybe it's because the creationists have asserted for years that humans coexisted with dinosaurs, and that the dinosaurs went extinct because they all missed getting on the Ark or something, so having one around today would mean we still coexist.  Q.E.D.

Hey, don't yell at me.  I'm not claiming it makes sense, I'm just telling you about it.

A highly scientific artist's conception of prehistory, as per the Creation Museum

In general, it's hard to see how the existence of "living fossils," organisms long thought to be extinct that have proven to be very much alive -- the coelacanth inevitably comes to mind -- is any kind of cogent argument against evolution, but the sad fact is that your average creationist wouldn't know a logical train of thought if it came up and bit them on the ass.  Be that as it may, the creationists are all in on the Mokèlé-Mbèmbé, with the general consensus being if one is discovered, all the evolutionary biologists will retreat in disarray and immediately join evangelical Christian churches.

So we have here a case of strange bedfellows -- the cryptozoologists, who are generally well-meaning even if they have a different standard for what constitutes reliable evidence than I do, are on the same team as the young-Earth creationists, who by and large want to turn the entire world into an autocratic Christian theocracy.

Me, I think it'd be cool if Mokèlé-Mbèmbé existed, but purely because it'd be a fascinating new area of biological study.  Sadly, the fact that there's exactly zero evidence other than hearsay (which, after all, isn't really evidence at all) argues against it.  For those of you who were hoping for confirmation of a Brachiosaurus lumbering around in the Congo Basin, I'm afraid it's kind of a non-starter.

And that goes double for those of you who think Adam and Eve had a pet velociraptor.

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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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Taking flight

One of the many things I find fascinating about the evolutionary model is how different lineages can happen on the same "solution" to the problems of surviving and reproducing, leading to similarities cropping up that don't result from common ancestry.  This is a phenomenon called convergent evolution, and explains why the North American flying squirrel and Australian sugar glider look a lot alike, even though they are only distantly related.  (The flying squirrel is a rodent, and the sugar glider a marsupial more closely related to kangaroos.)

I put the word "solution" in quotes and use it with caution, because this makes it sound like evolution is forward-looking, which it is not.  As Richard Dawkins explains brilliantly in his book The Blind Watchmaker, to trigger evolution, all you have to have is an imperfect replicator (in this case, DNA) and a selecting agent.  To phrase it more like Darwin would have put it: variation coupled with differences in survival rate.

I recall how surprised I was to learn that the eye has actually evolved multiple times.  Starting with light-sensitive spots, such as you still find today in many microorganisms, variations on different lineages came up with a variety of different "solutions" -- the pinhole-camera eye of a chambered nautilus, the cup-shaped eye of a flatworm, the compound eye of a fly, and our own eye with a transparent lens like that of a refracting telescope.  All these adaptations work just fine for the animal that has them.  (Eye formation in a number of species is controlled by the paired-box 6 [PAX6] gene, without which eyes won't form at all.  It's such a critical gene that it is conserved across thousands of species -- in fact, your PAX6 gene and a mouse's are identical, base-pair-for-base-pair.)

The reason this subject comes up is because of some research published in the journal Current Biology that showed another trait -- flight -- not only evolved separately in groups like insects and birds, but even in the dinosaurian ancestors of today's birds, it evolved more than once.

A team led by paleontologist Rui Pei of the Chinese Academy of Sciences analyzed bone and feather structure of various dinosaur groups to see if they flew, glided, or were using their feathers for a different purpose (such as keeping warm).  To their surprise, it was found that multiple lineages were capable of flying, or nearly so.  The authors write:

We [used] an ancestral state reconstruction analysis calculating maximum and minimum estimates of two proxies of powered flight potential—wing loading and specific lift.  These results confirm powered flight potential in early birds but its rarity among the ancestors of the closest avialan relatives (select unenlagiine and microraptorine dromaeosaurids).  For the first time, we find a broad range of these ancestors neared the wing loading and specific lift thresholds indicative of powered flight potential.  This suggests there was greater experimentation with wing-assisted locomotion before theropod flight evolved than previously appreciated.  This study adds invaluable support for multiple origins of powered flight potential in theropods (≥3 times), which we now know was from ancestors already nearing associated thresholds, and provides a framework for its further study.

Here are their results, in graphical form:

As you can see, actual birds -- labeled "Later-diverging avialans" near the bottom of the tree -- were far from the only ones to have flight capability.  Rahonavis, Microraptor, and several of the anchiornithines were probably fliers, and only the last mentioned is on the same clade as today's birds.

Flying is pretty useful, so it's no wonder that when feathers evolved from scales -- probably, as I mentioned earlier, in the context of warmth and insulation -- it was only a small step remaining toward lengthening those feathers to the point that their owners could catch a breeze and glide.  After that, the same kind of refinement took over that happened with the eye, and eventually, you have true flight.

So that's yet another cool bit of research about prehistory.  Wouldn't you like to know what those prehistoric fliers looked like?  I'd love to see them.  From a distance, because a lot of them were predators.  For example, Microraptor is Greek for "tiny hunter," and were a little like miniature velociraptors with wings.

If you wanted an image to haunt your dreams.

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The titan

One thing science teaches us is that just about everything is interesting if you look at it carefully enough.  Still, there's an ingrained human tendency to be overawed by superlatives -- the biggest, the heaviest, the brightest, the strongest, the most powerful.

It's why a recent fossil discovery from Somerset, England has made the headlines.  The rocks in Somerset, in the southwest of England, are mostly of Triassic age; it's not far from the famous "Jurassic Coast," which begins around Exmouth with Triassic sedimentary rocks that gradually become younger as you head west.  It's the site that the brilliant nineteenth century paleontologist Mary Anning studied -- becoming one of a very long list of talented women scientists who struggled for recognition by their male peers with tragically little success.

Somerset, which is a bit north from there, is also a great site for Mesozoic fossils, and some amateur fossil hunters recently found a doozy.  Father-and-daughter team Justin and Ruby Reynolds were searching along the north Somerset coast and saw what turned out to be a fossilized jawbone...

... of a creature which is estimated to have been twenty-five meters long.  (For my fellow Americans, twenty-five meters is about 130 bananas long.)

The animal was a type of ichthyosaur, a group that reached their height of diversity in the late Triassic Period.  We've known for a long time that ichthyosaurs were bizarre animals.  They were streamlined predators that look remarkably like dolphins, although they are only distantly related (making the two groups a great example of convergent evolution).  A number of them had an even stranger feature, which is the largest eye-diameter-to-body-size ratio of any animal known -- the well-named Ophthalmosaurus (Greek for "eye lizard") was six meters long and had eyes the size of basketballs.

But this new species could have eaten an Ophthalmosaurus as an appetizer and still had plenty of room for the entrée.  It's been dubbed Ichthyotitan severnensis -- more or less, "gigantic fish-thing from the Severn."  The fossil dates to about 202 million years ago.

[Image credit: artist Sergey Krasovskiy]

"I was highly impressed that Ruby and Justin correctly identified the discovery as another enormous jawbone from an ichthyosaur," said Dean Lomax, paleontologist at the University of Manchester, who verified the find and helped to classify it, in an interview with Science Daily.  "They recognized that it matched the one we described in 2018. I asked them whether they would like to join my team to study and describe this fossil, including naming it.  They jumped at the chance.  For Ruby, especially, she is now a published scientist who not only found but also helped to name a type of gigantic prehistoric reptile.  There are probably not many fifteen-year-olds who can say that!  A Mary Anning in the making, perhaps."

The Ichthyotitan, though, was one of the last of its kind; it, and a great many other species, were victims of the Late Triassic Mass Extinction, a poorly-understood extinction event that occurred around 201 million years ago and was only slightly smaller than the much better-known Cretaceous-Tertiary Extinction that would happen 135 million years later.  The most likely explanation of the Late Triassic event is volcanism and outgassing from the Central Atlantic Magmatic Province, the mantle upwelling from which would ultimately split up Pangaea and open the Atlantic Ocean, but that point is still being argued over by geologists and paleontologists.

Whether this particular Ichthyotitan was killed during the extinction event itself is, of course, impossible to tell, but the fossil dates to almost exactly the right time.  Its discovery also ramps up the search for more fossils along the north Somerset coast.  "It is quite remarkable to think that gigantic, blue whale-sized ichthyosaurs were swimming in the oceans around what was the UK during the Triassic Period," Lomax said.  "These jawbones provide tantalizing evidence that perhaps one day a complete skull or skeleton of one of these giants might be found.  You never know."

It's a hell of a find -- a bone from a creature in contention for the largest animal known.  I don't know about you, but it's hard even to imagine a predator that big.  The late Triassic must have been an impressive-looking place...

... observed, of course, from a safe distance.

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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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Lords of the air

Ever since I was a kid, my favorite group of dinosaurs has been the pterosaurs.

These are one of the six groups of animals that independently evolved flight, or at least significant capacity for gliding (the others are insects, birds, bats, flying squirrels, sugar gliders, and colugos).  They had incredible diversity at their height, during the Jurassic and Cretaceous Periods, from the pint-sized Sordes pilosus (with a sixty-centimeter wingspan) to the almost unimaginably huge Quetzalcoatlus northropi (with a ten-meter wingspan, as big as a light plane).

Most of them were probably clumsy on the ground -- it's hard to imagine how Quetzalcoatlus got off the ground -- but in the air, they were nimble, maneuverable, and fast.  The smaller ones were probably insect-eaters; the larger ones likely fed on fish, although a terrestrial diet of small reptiles and mammals is also possible. 

What brings all this up is the discovery of a new species of pterosaur, one of dozens that have been identified from the Jehol Biota, a stupendous fossil deposit in northeastern China near Huludao.  This fossil bed has produced not only pterosaurs but incredibly well-preserved species of prehistoric birds and other vertebrates -- it's like a tapestry of late Cretaceous animal life.

"Pterosaurs comprise an important and enigmatic group of Mesozoic flying reptiles that first evolved active flight among vertebrates, and have filled all aerial environmental niches for almost 160 million years," said Xiaolin Wang, of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences, who co-authored the paper describing the discovery.  "Despite being a totally extinct group, they have achieved a wide diversity of forms in a window of time spanning from the Late Triassic to the end of the Cretaceous period.  Notwithstanding being found on every continent, China stands out by furnishing several new specimens that revealed not only different species, but also entire new clades."

This includes the newly-discovered Meilifeilong youhao, belonging to the family Chaoyangopteridae, which is represented at the site by two other species that have been found nowhere else.

Meilifeilong looked like something out of a nightmare, if the artist's reconstruction is accurate (and probably even if it isn't):

[Image courtesy of artist Maurilio Oliveira]

The name means "beautiful flying dragon," which I doubt is what I'd say if I saw one, but what I'd say is borderline unprintable so we'll leave it at that.

It's astonishing to think of how long these creatures ruled the skies -- from the late Triassic until the very end of the Cretaceous, a time span of around 160 million years.  Had change not come in the form of the Chicxulub Meteorite collision, they might well still be here, soaring on thermals above our forests and lakes and oceans, the undisputed lords of the air.  And even if we now know them only from fossils, they still can't help but impress.

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A new view of the "eye lizard"

I am forever astonished at the level of detail we can infer from fossils that are hundreds of millions of years old.

The most recent example of this came from analysis of a fossil of Stenopterygius, an ichthyosaur that lived during the Jurassic Period (this particular fossil has been dated to about 180 million years ago).  We usually think of fossils as preserving bones and teeth, and occasionally impressions of scales or skin or feathers -- but this one was so finely preserved that researchers have been able to make some shrewd inferences about color, metabolism, and the structure of soft tissues.

Artist's conception of Stenopterygius [Image licensed under the Creative Commons Nobu Tamura (http://spinops.blogspot.com), Stenopterygius BW, CC BY-SA 3.0]

We've known for a long time that ichthyosaurs are bizarre animals. They were streamlined predators that look remarkably like dolphins, although they are only distantly related (making the two groups a great example of convergent evolution).  A number of them had an even stranger feature, which is the largest eye-diameter-to-body-size ratio of any animal known -- the well-named Ophthalmosaurus (Greek for "eye lizard") was six meters long and had eyes the size of basketballs.

Stenopterygius was a bit smaller, with an average adult size of four meters.  But up until recently, all we've been able to do is speculate on what it might have looked like, and how it behaved.  A discovery in Germany, described in a paper in Nature called "Soft-Tissue Evidence for Homeothermy and Crypsis in a Jurassic Ichthyosaur" and authored by no fewer than 23 scientists, has given us incredibly detailed information on these oddball dinosaurs.

The authors write:

Ichthyosaurs are extinct marine reptiles that display a notable external similarity to modern toothed whales.  Here we show that this resemblance is more than skin deep.  We apply a multidisciplinary experimental approach to characterize the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of the Early Jurassic ichthyosaur Stenopterygius.  Our analyses recovered still-flexible remnants of the original scaleless skin, which comprises morphologically distinct epidermal and dermal layers.  These are underlain by insulating blubber that would have augmented streamlining, buoyancy and homeothermy.  Additionally, we identify endogenous proteinaceous and lipid constituents, together with keratinocytes and branched melanophores that contain eumelanin pigment.  Distributional variation of melanophores across the body suggests countershading, possibly enhanced by physiological adjustments of colour to enable photoprotection, concealment and/or thermoregulation.  Convergence of ichthyosaurs with extant marine amniotes thus extends to the ultrastructural and molecular levels, reflecting the omnipresent constraints of their shared adaptation to pelagic life.

So from a 180-million-year-old fossil, we now know that Stenopterygius (1) was a homeotherm (colloquially called "warm-blooded"), (2) had a blubber layer much like modern dolphins and whales, and (3) were countershaded -- dark on top and light underneath, to aid camouflage -- similar to dozens of species of modern fish.

This level of preservation is extremely unusual.  "Both the contour of the body and the remains of internal organs are clearly visible," said paleontologist Johan Lindgren of the University of Lund, who co-authored the paper.  "Surprisingly, the fossil is so well preserved that it is possible to observe individual cell layers inside the skin."

"This is the first direct chemical evidence of warm blood in an ichthyosaur, because a subcutaneous fat layer is a characteristic of warm-blooded animals," said Mary Schweitzer of North Carolina State University, also a co-author.  "Ichthyosaurs are interesting because they have many features in common with dolphins, but they are not related at all to these mammals that inhabit the sea.  But the enigma does not stop there...  They have many characteristics in common with living marine reptiles, such as sea turtles; but we know from the fossil record that they gave live birth to their young...  This study reveals some of those biological mysteries."

Which is pretty astonishing.  I've always had a fascination for the prehistoric world, and have spent more time than I like to admit wondering what it might have been like to live in the Jurassic world. This research gives us one more piece of information -- about a fierce prehistoric predator that shared some amazing similarities to creatures that still swim in our oceans.

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Parallel problem solving

One of the many fascinating aspects of evolution is how nature happens upon the same solutions to environmental problems, over and over.

Two of the best examples of this are eyes and wings.  True eyes evolved from simple photoreceptive spots at least four times: the vertebrate eye, with its complex system of lenses and retinas; the pinhole-camera eyes of the chambered nautilus and other cephalopods; the compound eyes of insects; and the rows of separate spherical eyes in clams and scallops.  Wings, on the other hand, evolved independently no fewer than six times: bats, birds, insects, pterosaurs, flying squirrels, and colugos (the last two count if you include gliding along with true powered flight).

The reason is simple.  There are a handful of problems animals have to overcome (perception/sensation, nutrition, reproduction, locomotion, avoiding environmental dangers, and avoiding predation) and a limited number of ways to accomplish them.  Once (for example) photoreceptive eyespots develop in an animal, natural selection for improving the sensitivity of those spots takes over, but how exactly you do that can differ.  The result is you end up with vision evolving over and over, and each time, the organ is structured differently, but accomplishes the same thing.

Evolution, it seems, is the law of whatever works.

This has interesting implications about what extraterrestrial life might look like.  I very much believe that certain features will turn out to be constrained in any conceivable species -- the presence of locomotor organs, organs sensitive to sound, light, heat, and touch, and so on -- but also, that the way those organs are arranged and configured could be very differently from anything we have on Earth.

This "multiple solutions to the same problems" idea is what immediately came to mind when my friend and fellow writer Gil Miller, whose inquisitive mind and insatiable curiosity have provided me with many a topic here at Skeptophilia, sent me a link from Phys.org about hollow bones in dinosaurs.  Endoskeletons such as our own exist in an interesting tension.  They have to be solid enough to support our weight, but the better they are at weight-bearing, the heavier they themselves are.  The mass of an animal in general increases much faster than its linear dimensions do; double a mouse's height, keeping its other proportions the same, and it will weigh about eight times as much.  This is why in order for the whole system to work, the proportions have to change as species increase in size.  A mouse's little matchstick legs would never work if you scaled it up to be as big as a dog; at the extreme end, consider the diameter of an elephant's legs in relation to its size.  Anything narrower simply wouldn't support its weight.

[Nota bene: this is why if you were traumatized when young by bad black-and-white horror movies about enormous insects wreaking havoc, you have nothing to worry about.  If you took, for example, an ant, and made it three meters long, its proportionally tiny little legs would never be able to lift it.  The worst it could wreak would be to lie there on the ground, helpless, rather than eating Tokyo, which is what the horror movie monsters always did.  One got the impression the inhabitants of Tokyo spent ten percent of their time working, relaxing, and raising families, and the other ninety percent being messily devoured by giant radioactive bugs.]

But back to the Phys.org article.  A detailed analysis of the bone structure of three different dinosaur lineages -- ornithischians, sauropodomorphs, and herrerasaurids -- found that while all three had landed on the idea of internal air sacs as a way of reducing the mass of their large bones, the structures of each are different enough to suggest all three evolved the feature independently.  Once again, we have an analogous situation to eyes and wings; identical problem, parallel solutions.  The problem here is that large body size requires heavy bones that require a lot of energy to move around, and the solution is to lighten those bones by hollowing them out (while leaving the interstices connected enough that they're still structurally sound).  And three different clades of dinosaurs each happened upon slightly different ways to do this.

Herrerasaurus ischigualastensis [Image licensed under the Creative Commons Eva Kröcher, CC-BY-SA]

It's fascinating to see how many ways living things happen upon similar solutions to the problems of survival.  Evolution is both constrained and also infinitely creative; it's no wonder we are so often in awe when we look around us at the natural world.  The "endless forms most beautiful and most wonderful" Darwin spoke of in the moving final words of The Origin of Species never fail to astonish -- especially since the brains we use to comprehend them are just one of the end products of those very same processes.

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