Survival of the fittest is a strange concept. What makes one more “fit” than another? Is it physical strength, brains, or luck? Or is it some cocktail of all three? For decades, scientists have studied creatures of the past trying to figure out what made some carry on and others sputter out.
The Arctic was once home to the woolly mammoth, also called the Mammuthus primigenius. Thousands of years ago, these giant, furry elephant-like beasts prowled the land…until they didn’t. Recently, the experts working to uncover what really caused their extinction found new evidence that might just put the mystery to rest.
When we think of the woolly mammoths crossing the Arctic, they feel too far out of reach to even imagine. While the last woolly gave up the ghost thousands of years ago, their needs were quite similar to the needs of present-day herbivores.
However, there’s lot we didn’t know about these monstrous mammals. Most of the woolly mammoths called the Arctic’s mainland to be home, but a group of them resided elsewhere.
Wrangel Island — just off the coast of eastern Siberia — held a bundle of woolly mammoths, and for one reason or another (which we’ll get to), they outlived the woollys living in the Arctic mainland. There was something special happening on Wrangel Island…
In fact, this was no fluke: the Wrangel Island mammoths outlived the mainland mammoths by 7,000 years. What’s even crazier is that the island woollys died off just 4,000 years ago.
Let’s put that in perspective. The last of the woolly mammoths went extinct after the ancient Egyptians built the pyramids at Giza, which contradicts what scientists had once thought. But how?
Well, research done by Laura Arppe, of the Finnish Museum of Natural History, and her colleagues digs deeper into the mysterious survival and extinction of the island mammoths. They were determined to find out what “catastrophic” event destroyed this fascinating species.
Using mammoth teeth and bones found on the island, they detected the nature of the group’s diet, nutrition, and metabolism. They then analyzed their carbon and nitrogen isotopes, which help interpret “the nutrition and metabolic functioning” of the woollys prior to their extinction.
A 2017 study showed that a “genomic meltdown” induced the demise of the woolly mammoths, as the species experienced mutations that caused severe problems: they couldn’t synthesize proteins, which caused a loss of smell, for instance. Laura found something different.
While the 2017 study, which was published in PLOS, offered a complex, seemingly plausible scenario, Laura’s findings exhibit that something much simpler led to the extinction of these graceful beasts.
Laura’s research began with examining the dietary well-being of the Wrangel Island mammoths in order to gauge a potential lack in resources. Based on this, Laura found no “alarming long-term changes” in habitat or climate. Hmm.
“No one had looked at what was going on with the dietary ecology of the Wrangelian mammoths, and with all these other observations related to diet, it was high time to do so,” Laura said.
“Judged from the numbers of radiocarbon-dated mammoth bone finds on Wrangel Island, this last island population appears to have vanished rather abruptly,” she continued. This had Laura perplexed, so she and her team were on the woolly case.
And since major changes in climate and range reduction happened way before the mammoths went extinct, approximately 4,000 to 6,000 years prior, it likely had nothing to do with their fateful collapse.
So, again: what exactly happened to these island guys 4,000 years ago? Well, though it wasn’t related to climate change, the evils of Mother Nature still could’ve caused mass starvation via “icing events.”
When rain on snow created a hard, icy ground, it became impenetrable to the poor, hungry woolly mammoths, who needed to eat their greens and other nutritious plants, such as poppies, buttercups, and anemones.
Though the dietary well-being of the Wrangel Island mammoths was nearly the same as that of the Siberian mammoths, the island mammoths had one superior trait, a trait that could explain their extended survival.
The island mammoths used their fat reserves during freezing winters, and the Siberian mammoths didn’t. But unfortunately, the fat reserves didn’t save the island mammoths from the icing events. In fact, these icing events affected a plethora of Arctic herbivores.
“20,000 musk oxen were starved to death in 2003 in the Canadian Arctic due to a rain-on-snow event,” Laura relayed. While Laura and her team thoroughly believe the icing events acted as the beginning of the end for the mammoths, they also suspect there could’ve been a lack of healthy fresh water.
The New York Times
Next, Laura and her team aim to study the water quality to either reject or confirm the hypothesis that “the drinking water supply of the animals had high levels of harmful or even toxic elements released from the local bedrock.” Right now, it’s still a mystery.
While Laura and her team discovered a brilliant anomaly in the world of Arctic research, the true reason behind the woolly mammoths’ extinction may forever be an enigma. Meanwhile, one of her contemporaries was focused on uncovering the truth about another mysterious extinction.
37-year-old Robert DePalma made this widely publicized discovery near Bowman, North Dakota, in 2012. After receiving a tip from a private fossil collector, DePalma and his team began excavating a site along the well-known Hell Creek Formation.
Most people would consider a preoccupation with bones concerning, though Robert DePalma’s love of the dead and buried is anything but peculiar. An aspiring paleontologist, the 37-year-old managed to turn his lifelong passion into a curator position for the Palm Beach Museum of Natural History.
Robert DePalma / Facebook
Initially, DePalma felt the site, dubbed “Tanis,” had little promise, something the collector had made him privy to prior to the excavation. However, after returning to Tanis in 2013, the paleontologist discovered there was more to this unassuming patch of rock than met the eye.
Robert DePalma / Facebook
Just a few meters below the surface, DePalma discovered a host of rare and unusual fossils, including those of species he claimed to have never seen before. It was an incredible find, though one set of bones in particular caught DePalma’s eye — and left him positively stumped.
Sciene Channel / Twitter
Beneath the skeleton of a freshwater paddlefish, DePalma discovered the tooth of a mosasaur, an enormous reptilian predator that made its home in the oceans of the Early Cretaceous period. This puzzled DePalma and his team, for there was no way this creature could’ve existed in the fresh waters of prehistoric North Dakota.
The layout of the find was also unusual, the fossils deposited haphazardly and some skeletons even buried vertically in the dirt. Combined with the fact that tektites — small bits of natural glass created from meteor impacts — were also present, everyone was left scratching their head.
Then, a lightbulb went off: could the tektite fragments found in the Tanis deposit have been scattered here by the asteroid that wiped out the dinosaurs? While some researchers would be quick to accept such a theory, the plausibility of this scenario isn’t exactly cut and dry.
The widely held belief that an asteroid impact caused the Cretaceous–Paleogene extinction event is primarily based on the presence of the KT layer. This 66-million-year-old band of earth stretches over nearly the entire globe and contains a high level of iridium, an element primarily found in asteroids.
This theory is also supported by the Chicxulub crater, a 112-mile impression in the Yucatan Peninsula that contains the same mineral make-up as the KT layer. Therefore, most scientists assume that the asteroid that created this crater scattered the iridium debris that ultimately wiped out the dinosaurs.
The Silver Ink
If this were the case, then, one would expect to find plenty of fossils in the KT layer: after all, it was during this time that nearly all life on Earth went extinct. However, this actually isn’t true at all — hardly any fossils have ever been found in this layer of rock.
In fact, most fossils are found about ten feet below the KT layer, which, geologically speaking, would amount to thousands of years between the death of these creatures and the fateful asteroid impact. Therefore, it seems highly unlikely that an extraterrestrial object reduced every last dinosaur to rubble.
Proponents of this alternate theory do still believe that an asteroid impact finished off the last of these prehistoric creatures, though they propose that factors like large-scale volcanic activity and climate change had already wiped out most of the dinosaurs by this point.
However, according to DePalma, the Tanis find was the key to finally putting this debate to bed. Not only were the fossils he discovered located within the KT layer, but their haphazard placement suggested they were deposited here just moments after the asteroid struck.
Robert DePalma / Facebook
With this information in mind, DePalma posited that the mile-high tsunamis created by the impact must’ve traveled up river valleys and into freshwater bodies, which is how the mosasaur tooth came to be here. This was big news.
Eager to share his discovery with the world, DePalma sat down with The New Yorker to share the exclusive details of his historic find. However, as soon as the story broke in April 2019, the paleontology community grew outraged.
Many of DePalma’s colleagues were upset that the paleontologist had chosen to share his story with The New Yorker instead of a reputable scientific journal. DePalma later published his discovery in Proceedings of the National Academy of Sciences, though many felt this account was significantly less detailed than his New Yorker piece.
Even prior to this, however, DePalma was considered by some to be a controversial figure in the world of paleontology. In 2015, he introduced a new species of dinosaur he’d recovered from the Hell Creek Formation dubbed Dakotaraptor, though after presenting the completed skeleton, it was discovered one of the bones belonged to a turtle.
DePalma also stirred up controversy with his business practices, as he retains all control of his specimens even after they’ve been placed in museums and university collections. He also reportedly funds his field work by creating replicas of his finds and selling them to private collectors.
Robert DePalma / Facebook
But the strangest discrepancy of all may be DePalma’s record of the discovery itself. While the paleontologist and his team have made claims about the large number of dinosaur fossils uncovered near the surface of the Tanis deposit, his article in PNAS only mentions one example in a supplementary document.
The San Diego Union-Tribune
As of now, additional papers on Tanis are being prepared that will hopefully clear up the confusion surrounding DePalma’s find. Until then, one can only wonder if DePalma’s discovery will truly change history or simply wind up as the fabrication of another would-be hero in search of fame and glory.
FallonCohen / Imgur