The ghost forests

I recently read paleontologist Riley Black's lovely book When the Earth Was Green: Plants, Animals, and Evolution's Greatest Romance, which looks at the prehistory of life on Earth through the lens of paleobotany.

While I know the charismatic megafauna like dinosaurs and saber-toothed tigers and giant ground sloths garner most of the attention, I've always found ancient plants equally interesting.  Part of that comes from my ongoing love of both gardening and wild plants, something I've experienced since I was about six and discovered F. Schuyler Mathews's Field Book of American Trees and Shrubs, with its hundreds of pages of descriptions and range maps and wonderful illustrations.  I can't even begin to estimate the amount of time I spent poring over its pages (and I still own my copy of it).

Once I gained a passing knowledge of the trees and shrubs and wildflowers I saw every day, I was shocked to find out that if I were to go back a few million years, I'd find an entirely different assemblage of plant species.  I know, it shouldn't have been a surprise; if the animals had changed, there's no reason the plants wouldn't have as well.  But I still found it astonishing when I found out that (for example) at the moment, there is exactly one extant species of ginkgo (the familiar, and beautiful, Ginkgo biloba), but in the past there had been hundreds, perhaps thousands, of species in the family:

A sampler of now-extinct Jurassic ginkgo species [Image licensed under the Creative Commons Peter R. Crane, Pollyanna von Knorring, Fossil Ginkgoales, CC BY 4.0]

Riley Black does a masterful job of tracing the evolutionary history of plants from their origins to recent times, and her signature lucid writing style makes the subject completely captivating.  One of the chapters deals with an odd period of Earth's history -- the Cretaceous Resinous Interval, a span of about fifty million years during which there was intense diversification amongst gymnosperms, a group that includes not only ginkgos, but the superficially palm-like cycads and the much more familiar conifers.

Anyone who has ever leaned up against a pine or spruce tree knows about their impossibly sticky, golden-brown, aromatic sap.  This glop, so unfortunate for skin and clothing, evolved as a way of sealing wounds and preventing insect damage.  So in a relatively short time, we see the evolution of hundreds of species of plants that produced the stuff -- and, when it met the right conditions, hardening into amber.

Most of the world's amber, whether from Burma or the Baltic region or the highlands of Ecuador and Peru, formed during this time.  Amber has been popular for jewelry-making since the time of the ancient Greeks, and probably before; in fact, an interesting linguistic side-note is that the Greek name for amber, ἤλεκτρον, is where our words electron and electricity come from (due to amber's property of gaining a static charge when rubbed with a silk cloth).  But amber really came into the popular consciousness because of Jurassic Park, wherein some scientists extract dinosaur blood from bloodsucking insects trapped in amber, and use it to clone dinosaurs, with predictable results.

[Nota bene: it's thought that the upper bound for the survival of DNA in amber, even with optimal conditions, is around a million years, not the hundreds of millions required by Jurassic Park.  And even that is likely to be an overestimate.  In 2013, scientists tried -- and failed -- to extract intact DNA from a bee trapped in ten thousand year old copal, an amber precursor.]

That doesn't mean it can't have phenomenal paleontological significance, however, even if we're unlikely to have velociraptors stalking us any time soon.  The reason the topic comes up is a paper that appeared last week in Communications Earth about 112-million-year-old amber unearthed in an Ecuadorean quarry, which contained so many inclusions of insects, pollen, and seeds that it's being called a "Cretaceous time capsule."

A midge from the Ecuadorean amber.  Check out how well preserved those compound eyes and antennae are!  [Image credit: Mónica Solórzano-Kraemer]

The number of insect and arachnid taxa represented, as well as the pollen and other plant fossils discovered, paint a remarkably detailed picture of the ecosystem back then.  The authors write:

The new palaeobotanical evidence suggests the presence of a diverse and humid, low-latitude forest in north-western Gondwana during the early Albian...  The strata in this quarry reveal a vertical evolution of various palaeoenvironments, including proximal braided rivers, lacustrine systems, hyperpycnal [high-density, high-sediment] flows, and distal braided rivers during the Albian...  Pollen and plant macrofossils show abundant ferns and fern-allies that likely grew in the understory and/or near water bodies, in a forest dominated by araucariacean resinous trees.  The overall palynological and plant macrofossil association found in the Genoveva quarry, particularly the high diversity of pteridophytes and the presence of moderately thick coal seams in the stratigraphic sequence, indicates a humid environment, similar to previous reports in other but less studied north-western tropical South American sites.

The presence of relatively abundant chironomid flies and one trichopteran as bioinclusions—both insect groups with aquatic larval stages—further supports the interpretation of predominantly humid conditions during resin production and deposition.

Fascinating to think that if you went back there, in that thriving humid lowland forest, you wouldn't see a single modern plant species.  Not one.  Groups, sure -- we still have araucariacean trees around today (the most familiar being the Norfolk Island pine and the monkey-puzzle tree) -- but our modern forests, even in habitats with similar climates, have no species in common with those that produced the 112-million-year-old Genoveva amber. 

Change is always the way of things, but still, it strikes me as sad that all those many forms most beautiful and most wonderful (to swipe Darwin's pithy phrase) are gone.  Last week at the Tompkins County Friends of the Library Used Book Sale -- a twice-a-year, three week long, must-attend event for any bibliophiles within driving distance of Ithaca, New York, and which offers a quarter of a million used books each go round -- I picked up a real prize in a lovely illustrated paleobotany text, with drawings and fossil photographs representing over a thousand different species of plants no longer to be found anywhere on Earth.

I think this morning I'll spend some time flipping through its pages, and dream of wandering through the ghostly forests of prehistory.

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The flora of prehistory

I grew up around plants.  Well, everyone does, more or less, but my parents were dedicated gardeners and naturalists.  My dad grew show-quality tea roses and taught me how to recognize the trees of my native Louisiana from the shapes of the leaves and texture of the bark when I was still in elementary school.  My mom's flower gardens more than once had people pulling over to take photographs.

Regular readers of Skeptophilia are well aware of my fascination with prehistoric animals -- like many kids I grew up with books on dinosaurs (and posters of dinosaurs and models of dinosaurs...).  So it shouldn't have been a surprise that I was thrilled when I found out that just like the animals of prehistory, the plants of prehistory were different than the ones we have today.  But I recall that my interest was mixed with shock -- if I went back to the Cretaceous Period, not only would there be T. rexes and triceratopses stomping about, but the plants through which they'd have been stomping wouldn't have been the familiar oaks and ashes and hollies and camellias that were so familiar, but an entirely different flora in which I doubt there'd have been a single species I could have identified.

Well, maybe a couple, if not to species, at least to family.  Some of the earliest flowering plants were magnolias, and from the fossilized flowers, they look pretty much like... magnolias.  Ferns have been around for a long, long time (far predating the dinosaurs, in fact), and conifers like the common pines, cedars, and cypresses I saw every day were plentiful all the way back in the Triassic Period, 240-odd million years ago.  

But that's about it.  And although some of the groups were there, the species themselves would have been different ones than what we see around us today.  Imagine it: forests of plants with huge and wonderful biodiversity, in which you wouldn't recognize a single one that's familiar.

The reason I'm thinking about all this floral prehistory is a link to some cool research that showed up last week in Geology that a friend and frequent contributor to Skeptophilia sent me, about a discovery of a phenomenally well-preserved flower in hundred-million-year-old amber from Myanmar.  

Valviloculus pleristaminis, flower in lateral view.  Image credit: Poinar, Jr. et al., doi: 10.17348/jbrit.v14.i2.1014.

Dubbed Valviloculus pleristaminis (the genus name comes from the Latin valva -- "a folding door" -- and loculus -- "compartment;" the species name means "lots of stamens"), the little flower is only distantly related to any extant species.  Botanists think that Valviloculus might be allied to one of two rather obscure families of plants native to the Southern Hemisphere -- Monamiaceae and Atherospermataceae -- but that's only a preliminary analysis.

Atherosperma moschatum, an Australian species that may be one of the closest living cousins to Valviloculus [Image is in the Public Domain courtesy of photographer Peter Woodard]

"This isn't quite a Christmas flower but it is a beauty, especially considering it was part of a forest that existed 100 million years ago," said emeritus professor George Poinar, Jr., of Oregon State University, who led the research into the newly-discovered species.  "The male flower is tiny, about two millimeters across, but it has some fifty stamens arranged like a spiral, with anthers pointing toward the sky.  Despite being so small, the detail still remaining is amazing.  Our specimen was probably part of a cluster on the plant that contained many similar flowers, some possibly female."

What's even more mind-blowing is something I've pointed out before; given how difficult it is to form a good fossil and then have it survive intact for millions of years, the species we know about (both animal and plant) probably represent about 1% of what was actually alive back then.  The vast majority of species came and went, leaving no traces.  So if we were to travel back to the mid-Cretaceous, when Valviloculus was living and flowering in the prehistoric forests, not only would we see it, but literally hundreds of other long-gone species as varied, attractive, weird, and fascinating as the ones we have today.

Imagine the colors, shapes, and scents, plants from tiny sprigs all the way to towering trees, and none of which we still have with us now.  Truly, in Darwin's words, evolution produced -- and continues to produce -- "endless forms most beautiful and most wonderful."

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This week's Skeptophilia book recommendation is apt given our recent focus on all things astronomical: Edward Brooke-Hitching's amazing The Sky Atlas.

This lovely book describes our history of trying to map out the heavens, from the earliest Chinese, Babylonian, and Native American drawings of planetary positions, constellations, and eclipses, to the modern mapping techniques that pinpoint the location of stars far too faint to see with the naked eye -- and objects that can't be seen directly at all, such as intergalactic dust clouds and black holes.  I've always loved maps, and this book combines that with my passion for astronomy into one brilliant volume.

It's also full of gorgeous illustrations showing not only the maps themselves but the astronomers who made them.  If you love looking up at the sky, or love maps, or both -- this one should be on your list for sure.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

A time capsule in amber

Today we're going to turn away from the generally atrocious stories in the news and focus on some science that's just plain cool.

You probably all know by now that bird are dinosaurs.  Not that they're related to, or descended from, dinosaurs; they are dinosaurs, belonging to the clade Dinosauria of the Phylum Chordata, specifically a group called the saurischians ("lizard-hipped" dinosaurs).  As such, they're cousins to such behemoths as Tyrannosaurus rex, and also velociraptors, made famous by Jurassic Park.  (Nota bene: although pack hunters, they probably weren't smart enough to get out of a locked freezer.)

So think of that next time you see a sparrow flitting about.  That, my friends, is a flying dinosaur.

This comes up because of the recent discovery of a bird leg preserved in amber.  These sorts of fossils are pretty uncommon, so this one has really stirred the paleontologists up.  It dates to about 98 million years ago, putting it dead center in the Cretaceous Period, which ended with a (literal) bang, the double whammy of a huge meteorite collision (Chicxulub) and a stunningly huge volcanic eruption (the Deccan Traps).

This bird, however, was comfortably positioned 42 million years before any of that nasty stuff happened, although that probably wasn't much consolation when he got mired in tree sap and probably either starved or was picked off by a predator, leaving his leg encased for us to find.  Here's the fossil itself:

And a reconstruction by artists, courtesy of the journal Current Biology:

I do have to wonder a little about the reconstruction, given that this species -- christened Elektrornis chenguangi ("elektron" is Greek for "amber") -- belongs to a group called enantiornithines.  Speaking of interesting derivations; enantiornithine is Greek for "mirror-image bird," because the group had a reversed orientation of the shoulder articulation.  Anyhow, the reconstruction seems to ignore one of the most prominent features of this group to our 21st-century picture of what a bird should look like:

They had teeth.

Not great big nasty pointy ones, no, but teeth nonetheless.  Here's a skull of a different enantiornithine, Bohalornis:

[Image licensed under the Creative Commons Fanboyphilosopher (Neil Pezzoni), Bohaiornis skull reconstruction, CC BY 4.0]

So a little more ferocious-looking than the artist's reconstruction might indicate.

The weirdest thing about Elektrornis specifically is that it had a greatly elongated middle toe (which you can see not only in the reconstruction but in the photograph of the fossil itself).  What it was used for is unknown, although the team that did the research -- Lida Xing, Jingmai K. O’Connor, Luis M. Chiappe, Ryan C. McKellar, Nathan Carroll, Han Hu, Ming Bai, and Fuming Lei, of the China University of Geosciences, the Chinese Academy of Sciences, the Natural History Museum of Los Angeles, the University of Regina, and the University of New England (Australia) -- speculate that it probably was an adaptation for feeding or for grasping.

Not, probably, for flipping off other dinosaurs, which was my first thought.  But then, I'm a non-specialist.

So a pretty cool discovery in China, elucidating the origins of modern birds and their ties to extinct, more conventionally dinosaur-like species.  Makes me kind of sorry the big toothy birds are gone.  That would add a whole new level of excitement to birdwatching, wouldn't it?

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In August of 1883, one of the largest volcanic eruptions in human history (literally) obliterated an island in the Sunda Strait between Java and Sumatra.

The island was Krakatoa (now known by its more correct spelling of "Krakatau").  The magnitude of the explosion is nearly incomprehensible.  It generated a sound estimated at 310 decibels, loud enough to be heard five thousand kilometers away (sailors forty kilometers away suffered ruptured eardrums).  Rafts of volcanic pumice, some of which contained human skeletons, washed up in East Africa after making their way across the entire Indian Ocean.  Thirty-six thousand people died, many of whom were not killed by the eruption itself but by the horrifying tsunamis that resulted, in some places measuring over forty meters above sea level.

Simon Winchester, a British journalist and author, wrote a book about the lead-up to that fateful day in summer of 1883.  It is as lucid and fascinating as his other books, which include A Crack at the Edge of the World (about the 1906 San Francisco earthquake), The Map that Changed the World (a brilliant look at the man who created the first accurate geological map of England), and The Surgeon of Crowthorne (the biographies of the two men who created the Oxford English Dictionary -- one of whom was in a prison for the criminally insane).

So if you're a fan of excellent historical and science writing, or (like me) fascinated with volcanoes, earthquakes, and plate tectonics, you definitely need to read Krakatoa: The Day the World Exploded.  It will give you a healthy respect for the powerful forces that create the topography of our planet -- some of which wield destructive power greater than anything we can imagine.

Amber teething beads and alternative quackery

Every once in a while, I'll happen across a story that outright makes me angry.  Usually this has to do with a woo-woo claim that doesn't just put the believer at risk, but others as well.

And it's worse when the ones whose health and safety are being put in danger are children.  Children depend on adults to make good decisions, and when hype, credulity, and commercialism team up to sell parents a bill of goods, it is placing an innocent individual in harm's way -- and one who is not capable of standing up for him/herself, or necessarily even recognizing the danger.

This is the case with the latest fad in "holistic baby care" -- amber teething beads.  I was first alerted to this oddball idea by a regular reader of Skeptophilia, who asked me if I'd ever heard of such a thing.  I hadn't.  But a little bit of research brought me here, where we are given the following combination of half-truths and outright falsehoods:

• Amber releases "healing oils," which are absorbed through the skin and into the bloodstream.  (It doesn't.)
• Amber is "electromagnetically alive" and "produces significant amount of organic, purely natural energy."  (Well, it can be electrically charged if you rub it with a silk cloth -- but then, so can a balloon, and I've never seen "holistic medicine" sites recommending wearing necklaces made of balloons.)
• Amber contains succinic acid, which is good for you because it is an amino acid.  (Succinic acid is not an amino acid.)
• Succinic acid is a therapeutically proven analgesic.  (This is true, but you can suck on a blob of amber all day and not absorb enough succinic acid to reduce any pain you might be experiencing.)
• Wearing amber protects you against "the negative effects of electrical equipment such as computers, televisions, mobile phones, and microwave ovens."  (Controlled studies of exposure to electromagnetic fields from commonly-used equipment showed no health effects whatsoever, so there's nothing much to protect you from.)
• Amber is good for you because tree resin has anti-microbial properties.  (A good antiseptic works much better.)

Then, at the bottom of the page, they write, "Please note: Amber Artisans does not dispense medical advice."

Oh, no?  Then what were the preceding paragraphs of hogwash?  These people -- who are only one of dozens of sites I found that are now hawking amber for teething babies -- are clearly dispensing medical advice.  Erroneous advice, but medical advice nonetheless.

I'm wondering how long it'll be before the first baby chokes to death on an amber necklace.  These things have screw clasps, and the silk cord that the beads are strung on is supposed to break if sufficient tension is given -- reducing the strangulation risk -- but what if a bead pops off the necklace and is inhaled?  And then, we have the problem of sites such as this one -- that claim that amber can be used for other purposes than soothing teething pain, such as treating rashes and fevers.  So, compound the (1) pseudoscientific claims, with (2) the choking and strangulation risk, and finally (3) the fact that gullible parents are being convinced that children with treatable illnesses will be cured by wearing a necklace, and potentially delay seeking good medical care, and perhaps now you'll see why the whole thing made me furious.

We have lots of ways of giving our children their best shot at healthy lives.  Good diet, exercise, and the usual suite of childhood vaccinations (sorry, anti-vaxers, you're simply wrong) are still the best bets for avoiding the illnesses that used to kill tens of thousands of children annually (and still do, in some countries where medical care is poor or nonexistent).  We now have an excellent understanding of how immunity works, and can use that knowledge to benefit those who depend on us.  And if we take the time to learn a little bit of genuine science, it can immunize us adults as well -- against the false claims of hucksters who are trying to sell us medically worthless items as cure-alls.