Of rhinos and puppies

You're not alone if you immediately think "Africa" when you hear the word "rhinoceros."  The two largest and best-known species -- the black (Diceros bicornis) and white (Ceratotherium simum) rhinos -- are both native to the southern parts of Africa.  There are three additional extant species in southern Asia, however; the Indian (Rhinoceros unicornis), Javan (Rhinoceros sondaicus), and Sumatran (Dicerorhinus sumatrensis) rhinos.  The latter two are amongst the most endangered mammals in the world, with only about 60 and 245 individuals left, respectively.

Rhinos, though, used to be much more diverse, and much more common.  One of the most remarkable fossils ever discovered is the Blue Lake rhino, a fifteen-million-year-old cast of an extinct rhinoceros species called Diceratherium in what is now eastern Washington state.  The "remarkable" part is that it's fossilized in igneous rock, which isn't supposed to happen -- fossils are supposed to all be in sedimentary rock, right?  But what happened is there was a colossal eruption fifteen million years ago that produced the Columbia River Flood Basalts, releasing an estimated 174,000 cubic kilometers of lava, an amount that's hard to fathom.  Anyhow, this poor rhino was peacefully grazing, minding its own business, and suddenly BAM, it gets hit by a fast-moving, highly liquid lava flow, its body entombed then burned away.  Fast forward to 1935, when a fossil hunter named Haakon Friele discovered a strange cave in a basalt formation, crawled inside with a flashlight, and somehow thought, "Hey, this hole is shaped just like a rhino."  A bit later, a crew of paleontologists from the University of California - Berkeley were called in, and they made a plaster cast of the interior -- and sure enough, it's a cast of a very surprised-looking rhino who was very much in the wrong place at the wrong time.

There were other rhino species more recently, however.  The woolly rhinoceros (Coelodonta antiquitatis) was an ice-age species that lived pretty much everywhere in what is now Asia and Europe, but started declining in population about forty thousand years ago, dwindling until only a remnant population was left in Siberia.  The last ones died fourteen thousand years ago, give or take.

[Image licensed under the Creative Commons ДиБгд, Wooly Rhino15, CC BY-SA 4.0]

The blame for the woolly rhino's demise has been attributed to overhunting by early humans, but recent research suggests the cause was actually climate change.  In the paper, "Pre-Extinction Demographic Stability and Genomic Signatures in the Woolly Rhinoceros," by a team led by Edana Lord of the Swedish Museum of Natural History, we read the following:

Ancient DNA has significantly improved our understanding of the evolution and population history of extinct megafauna.  However, few studies have used complete ancient genomes to examine species responses to climate change prior to extinction.  The woolly rhinoceros (Coelodonta antiquitatis) was a cold-adapted megaherbivore widely distributed across northern Eurasia during the Late Pleistocene and became extinct approximately 14 thousand years before present (ka BP).  While humans and climate change have been proposed as potential causes of extinction, knowledge is limited on how the woolly rhinoceros was impacted by human arrival and climatic fluctuations.  Here, we use one complete nuclear genome and 14 mitogenomes to investigate the demographic history of woolly rhinoceros leading up to its extinction.  Unlike other northern megafauna, the effective population size of woolly rhinoceros likely increased at 29.7 ka BP and subsequently remained stable until close to the species’ extinction.  Analysis of the nuclear genome from a ∼18.5-ka-old specimen did not indicate any increased inbreeding or reduced genetic diversity, suggesting that the population size remained steady for more than 13 ka following the arrival of humans.  The population contraction leading to extinction of the woolly rhinoceros may have thus been sudden and mostly driven by rapid warming in the Bølling-Allerød interstadial.

So at least that's one calamity we're not responsible for.

On the other hand, another recent discovery shows that we might not have doomed the woolly rhino, but our best friends might have had a hand -- um, a paw -- in it.  A friend and long-time loyal reader of Skeptophilia sent me a link to an article about a mummified body of a dog found in Siberia that, when analyzed, was found to have bits of meat from a woolly rhino it its stomach.  "This puppy, we know already, has been dated to roughly 14,000 years ago," said researcher Love Dalén, also of the Swedish Museum of Natural History.  "We also know that the woolly rhinoceros goes extinct 14,000 years ago.  So, potentially, this puppy has eaten one of the last remaining woolly rhinos."

Dogs: Eating Stuff They Shouldn't Eat For the Past Fourteen Thousand Years.

So that's today's excursion into weird cul-de-sacs of zoology.  And honestly, I'm just as glad the temperate-area rhino species are gone, cool as they undoubtedly were.  We have enough trouble keeping the groundhogs and rabbits out of the vegetable garden, I can't imagine how we'd deal with rhinos tromping around the place.

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Fan of true crime stories?  This week's Skeptophilia book recommendation of the week is for you.

In The Poisoner's Handbook:Murder and the Birth of Forensic Medicine in Jazz Age New York, by Deborah Blum, you'll find out about how forensic science got off the ground -- through the efforts of two scientists, Charles Norris and Alexander Gettler, who took on the corruption-ridden law enforcement offices of Tammany Hall in order to stop people from literally getting away with murder.

In a book that reads more like a crime thriller than it does history, Blum takes us along with Norris and Gettler as they turned crime detection into a true science, resulting in hundreds of people being brought to justice for what would otherwise have been unsolved murders.  In Blum's hands, it's a fast, brilliant read -- if you're a fan of CSI, Forensics Files, and Bones, get a copy of The Poisoner's Handbook, you won't be able to put it down.

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

Unicorn survival

One of the arguments you'll hear from cryptid enthusiasts is that the various critters they claim are real are survivals.  Nessie, Mokele-Mbémbé, and the Bunyip are modern-day brachiosaurs or plesiosaurs.  Bigfoot, the Fouke Monster, the Almas, the Florida Skunk Ape, and the Yowie are hominids, possibly australopithecenes.  The Beasts of Bodmin Moor and Exmoor, and the Mngwa of Tanzania, are related to prehistoric cats.  Mothman is supposed to be... okay, I don't know what the fuck Mothman is supposed to be.  Maybe descended from the rare saber-toothed butterfly, I dunno.

[Nota bene: if you're curious about any of these and want more information, check out the excellent cryptid list on Wikipedia, which has these and many others, along with lots of highly amusing illustrations thereof.]

The possibility of prehistoric survival is not without precedent.  The most famous is the coelacanth, one of the bizarre lobe-finned fish found in fossil form in sediments from before the Cretaceous Extinction, 66-odd million years ago.  They were allied to the lineage that led to amphibians (although that split took place a lot longer ago, so they weren't direct ancestors), and had lobe-like proto-limbs that give the group their name.  They were thought to be long extinct -- until a fisherman off the coast of Madagascar caught one in 1938.

Even that iconic mammal of prehistory, the woolly mammoth, survived a lot longer than most people thought.  The last remnant populations were thought to have been in northern North America and Siberia on the order of 25,000 years ago -- until fossils were found on Wrangell Island, off the coast of Alaska, dating to around 3,800 years ago, making them contemporaneous with the building of the Great Pyramids of Egypt.

So it's always risky to date a bunch of fossils and conclude that the most recent one marks the end of the species.  Not only is fossilization uncommon (something I've touched upon before), but there can be small remnant populations left in out-of-the-way places, and our inferences about when species became extinct can be off.

Sometimes by a lot.  Take, for example, Elasmotherium, which was the subject of a paper in The American Journal of Applied Sciences that a friend and loyal reader of Skeptophilia sent me last week.  Elasmotherium has sometimes been nicknamed "the Siberian Unicorn," which is a little misleading, because the only similarities between it and the typical graceful, fleet-footed concept of the unicorn is that it had one horn and four legs.  Here's an artist's rendition of Elasmotherium:

[Image is in the Public Domain, courtesy of artist Heinrich Harder]

If your thought is that it looks more like a rhinoceros than a one-horned horse, you're correct; the elasmotheres are cousins to the modern African rhinos.  What's interesting about them is that they were around during the Pleistocene, reaching their peak during the repeated glaciations, and were thought to have died out as the climate warmed, on the order of 350,000 years ago -- but this study found fossils from Kozhamzhar in Kazakhstan that dated to around 26,000 years ago.

"Most likely, the south of Western Siberia was a refugium, where this rhino persevered the longest in comparison with the rest of its range," said Andrey Shpanski, a paleontologist at Tomsk State University, who co-authored the paper.  "There is another possibility that it could migrate and dwell for a while in the more southern areas."

So it's a good bet that the elasmotheres -- like the woolly mammoth -- persisted a lot longer than paleontologists realized.

This is the main reason why, despite my general skepticism, I'm hesitant to discount reports of cryptids out of hand.  That most of them are either hoaxes or else misidentification of perfectly ordinary modern animals seems pretty likely, but "most" doesn't mean "all."  I'm very much in agreement on this count with what astronomer Michio Kaku said about UFOs: "Perhaps 98% of sightings can be dismissed as fabrications or as perfectly natural phenomena.  But that still leaves 2% that are unaccounted for, and to me, that 2% is well worth investigating."

So I'm all for continuing to consider claims of cryptids, as long as we evaluate them based upon the touchstone for all scientific research: hard evidence.  It's entirely possible some animals thought previously to be extinct have survived in remote areas, and have given rise to what we now call cryptozoology.  If that's the case, though, it should be accessible to the tools of science -- and, truthfully, just be zoology, no "crypto" about it.

Except for Mothman.  That mofo is scary.  I'd just as soon that one stays in the realm of legend, thank you very much.

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In the midst of a pandemic, it's easy to fall into one of two errors -- to lose focus on the other problems we're facing, and to decide it's all hopeless and give up.  Both are dangerous mistakes.  We have a great many issues to deal with besides stemming the spread and impact of COVID-19, but humanity will weather this and the other hurdles we have ahead.  This is no time for pessimism, much less nihilism.

That's one of the main gists in Yuval Noah Harari's recent book 21 Lessons for the 21st Century.  He takes a good hard look at some of our biggest concerns -- terrorism, climate change, privacy, homelessness/poverty, even the development of artificial intelligence and how that might impact our lives -- and while he's not such a Pollyanna that he proposes instant solutions for any of them, he looks at how each might be managed, both in terms of combatting the problem itself and changing our own posture toward it.

It's a fascinating book, and worth reading to brace us up against the naysayers who would have you believe it's all hopeless.  While I don't think anyone would call Harari's book a panacea, at least it's the start of a discussion we should be having at all levels, not only in our personal lives, but in the highest offices of government.