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Humans are the only species with chins. Here are the wildest theories at to why.

Chinteresting, indeed.

Photo credit: Canva, Gage Skidmore/Wikipedia

The chins evolved to bring us Henry Cavill. Duh.

When we talk about what makes humans special, we usually point to our big brains, our opposable thumbs, our affinity for tool-making…or, more recently, the fact that we can turn oat milk into a personality trait.

But scientists say there’s something else that sets us apart from every other species on Earth. Something so ordinary you probably don’t even think about it when you look in the mirror.

It’s your chin. Yes, really. That tiny little nub of bone under your smile is one of the weirdest, most mysterious features in all of evolution.

No other animal has one. Not chimpanzees. Not gorillas. Not even our closest ancient relatives, the Neanderthals. Somewhere along the evolutionary line, humans woke up with a chin. Researchers have been trying to figure out why ever since, which has led to some pretty wild theories.

evolution, chin implants, cool history, science, pbs pbs eons, paleontology, smithsonian magazine Neanderthal media1.giphy.com

Chewing, by far, is the prevailing and most studied theory. After all, our ancestors’ jaws and teeth got smaller as our diets changed, and perhaps the chin evolved to help keep everything strong and supported. Flora Gröning, a biological anthropologist at the University of York, put that theory to the test by digitally modeling how human and Neanderthal jaws handled pressure. Turns out, she found, the chin does give our jaw a little extra reinforcement while chewing. Score one for Team Chewing.

But another camp believes it’s all about how we talk. In 1913, physician Louis Robison suggested that the chin developed to support the human language growing more complex, acting like a tiny shock absorber to protect our jaws from the muscular gymnastics required for human speech. Because let’s be honest, “She sells seashells by the seashore” is no easy task.

Then there’s a third, more scandalous idea: maybe it’s about attraction. According to the sexual selection theory, our chins could be nature’s version of a dating app filter. Studies have found that women may subconsciously prefer men with broader, more prominent chins, which signal testosterone and “good genes.” Men, on the other hand, often favor women with narrower, softer chins—traits linked to higher estrogen levels.

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This theory was strengthened when researchers Zaneta Thayer and Seth Dobson examined nearly 200 skulls from around the world and noticed that male chins did tend to be taller and more pronounced. That suggests our chins might have been shaped, at least in part, by what our ancestors found attractive.

However, the more outlandish theories involve laundry…and boxing. Some think that chins came about so that we could clamp down on cloth while folding, while others think that they evolved to take a punch.

Still others think chins just sort of happened. No actual purpose, just a byproduct of evolution. Wouldn’t be the first time. (Looking at you, belly buttons)

In the end, there may not be one single reason we have chins. It could be a mix…a little bit of chewing, a little bit of talking, and a little bit of flirting. A little bit of punching? Evolution, it seems, has range.

- YouTube www.youtube.com

So next time you rest your hand under your chin in deep thought, give it some credit. That humble bump of bone may not get the glory our brains do, but it’s uniquely ours. A small, sculpted reminder that being human is as much about mystery as it is about the mind.

Special thanks to Smithsonian Magazine and PBS Eons for supplying such interesting info!

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Terrifying Tyrannosaurs were social creatures who hunted together like wolves, new research says

Jon Butterworth on Unsplash

When we think of what a Tyrannosaurus looked like, we picture a gargantuan dinosaur with a huge mouth, formidable legs and tail, and inexplicably tiny arms. When we picture how it behaved, we might imagine it stomping and roaring onto a peaceful scene, single-handedly wreaking havoc and tearing the limbs off of anything it can find with its steak-knife-like teeth like a giant killing machine.

The image is probably fairly accurate, except for one thing—there's a good chance the T. rex wouldn't have been hunting alone.

New research from a fossil-filled quarry in Utah shows that Tyrannosaurs may have been social creatures who utilized complex group hunting strategies, much like wolves do. The research team who conducted the fossil study and made the discovery include scientists from the U.S. Bureau of Land Management, Denver Museum of Nature and Science, Colby College of Maine, and James Cook University in Australia.

The idea of social Tyrannosaurs isn't entirely new—Canadian paleontologist Philip Curie floated the hypothesis 20 years ago upon the discovery of a group of T. rex skeletons who appeared to have died together—but it has been widely debated in the paleontology world. Many scientists have doubted that their relatively small brains would be capable of such complex social behavior, and the idea was ridiculed by some as sensationalized paleontology PR.

However, another mass Tyrannosaurus death site found in Montana lent scientific credence to the theory, and now the Utah discovery has provided even more evidence that these massive creatures weren't solitary predators, but social hunters.

"The new Utah site adds to the growing body of evidence showing that Tyrannosaurs were complex, large predators capable of social behaviors common in many of their living relatives, the birds," said Joe Sertich, curator of dinosaurs at the Denver Museum of Nature & Science. "This discovery should be the tipping point for reconsidering how these top carnivores behaved and hunted across the northern hemisphere during the Cretaceous."

The Utah site, known as the Rainbows and Unicorns Quarry (yes, really), has provided paleontologists a wealth of fossils since its discovery in Grand Staircase-Escalante National Monument in 2014. Such sites are rare, and the findings in them are often difficult to interpret.

"We realized right away this site could potentially be used to test the social Tyrannosaur idea. Unfortunately, the site's ancient history is complicated," said U.S. Bureau of Land Management paleontologist Dr. Alan Titus. "With bones appearing to have been exhumed and reburied by the action of a river, the original context within which they lay has been destroyed. However, all has not been lost."

Researchers used a multi-disciplinary approach, examining the physical and chemical evidence to determine that a group of 12 Tyrannosaurs at the Utah site were likely killed during a flood that washed their remains into a lake. "None of the physical evidence conclusively suggested that these organisms came to be fossilized together, so we turned to geochemistry to see if that could help us," said Dr. Celina Suarez of the University of Arkansas. "The similarity of rare earth element patterns is highly suggestive that these organisms died and were fossilized together."

The Tyrannosaurus fossils are dated at 76.4 million years old. The research team has also found fossils from seven species of turtles, multiple fish and ray species, two other kinds of dinosaurs, and a nearly complete skeleton of a juvenile (12-foot-long) Deinosuchus alligator.

It's always a fun day when we find out one of history's most terrifying creatures is even more terrifying than we believed. One Tyrannosaurus sounds scary enough, but a group of them strategizing to hunt? That's definitely worse, like a coordinated troupe of Godzillas. No thanks, Cretaceous Period. We're good here.

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