Scientists Unearth a Giraffe Ancestor That Had Four Horns Instead of Two

María Ríos et al / PLOS One
María Ríos et al / PLOS One

The recently uncovered fossil of an early giraffe ancestor exhibits some noticeable differences from its modern giraffe descendants. It's several feet shorter, roamed Europe instead of Africa, and sports four horns on its head instead of two. As The New York Times reports, the discovery, outlined in a recent study in the journal PLOS One, sheds new light on the evolutionary history of the long-necked mammals.

The fossil belongs to a newly discovered species of extinct giraffe dubbed Decennatherium rex. It was excavated near Madrid, Spain along with the remains of three other specimens of the same animal, but the other fossils don't compare to the near-complete condition of the first. The creatures lived in the area 9 million years ago, moving the timeline of giraffids' presence in Europe further back than experts previously thought.

The ancient species stood 9 feet tall, making it shorter than today's giraffes. While D. rex lacked the modern giraffe's distinctive towering neck, paleontologists were able to classify it as a member of the same family by looking for its double-lobed canine teeth and the bony protrusions on its head called ossicones. Giraffes and okapis are the only remaining members of their family (though the giraffes we think of as one species may actually consist of four), and they both have one set of two ossicones that rise straight from the top of the skull.

Artist rendering of giraffe relative.

In addition to the two small horns at the front of its head, D. rex also appears to have had a second set. This feature differed in females and males: In the female D. rex, ossicones grew to be about 2 inches, while in males their second set could reach up to 16 inches. Though they varied in size, the fact that ossicones appeared in both sexes suggests that they didn't just evolve as a way for males to compete for mates.


The details of giraffe evolution, like how the species developed its elongated neck, are mysteries scientists are just starting to unravel. This most recent discovery adds another important link in the long history of the Giraffidae family.

[h/t The New York Times]

All images courtesy of María Ríos et al. in PLOS One

Treat Your Very Good Dog to An Adorable Hawaiian Shirt This Summer

twygg, iStock/Getty Images Plus
twygg, iStock/Getty Images Plus

This summer, treat your very good doggo to a very stylish Hawaiian polo shirt—because dogs are people, too.

The shirt, made by Expawlorer and available through Amazon, features a vibrant Hawaiian island scene that will surely highlight the sparkle of adventure in your dog’s eyes and remind you that they deserve an extra belly rub for staying on top of seasonal trends.

It’s made from a natural cotton that will help keep your dog cool beneath the heat of the blistering summer sun, and the Velcro fastener on the front of the shirt will ensure a stress-free dressing experience (for both of you).

Dog wearing a Hawaiian shirt on the beach
Expawlorer, Amazon

Does your dog have an unparalleled penchant for making messes? Fret not: The shirt is machine washable and can be thrown in the dryer, too.

Prices start at $12, and you can purchase it in sizes small, medium, large, and extra large. According to the product description, it fits small and medium-sized dogs best; one reviewer notes that the extra large is snug on their 60-pound dog. If the petite sizing prompts you to wonder, “Would this fit my cat?,” the answer is yes. The small size is designed for pets with a 10-inch neck circumference, which would work for the average cat, though it may be a bit loose on smaller kitties. (“Would my cat let me put this on them?” is an entirely different question that only your cat can answer.)

The Hawaiian shirt is much more than a bold and festive fashion statement—its rich history dates back to the 1920s, and the look has been embraced by a variety of human celebrities, including Frank Sinatra and Elvis Presley.

However, if the “life of the party” connotation of the Hawaiian shirt doesn’t quite fit the personality of your pet, here are some other options.

[h/t Her]

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Female Lab Rats Are the Victims of Gender Bias, Too

Alexthq // Getty Images
Alexthq // Getty Images

Sexism in the workplace isn’t limited to humans. Because neuroscientists presumed that hormonal fluctuations in female lab rats would affect their test results, they have mainly stuck to studying male lab rats. But they may not be getting the whole story, reports Bethany Brookshire at Science News.

Female lab rats do indeed have hormonal surges that affect their behavior—but so do males. Previous research has shown that females consume more cocaine when in heat (in other words, with higher estrogen levels) than at other times. But males with low or high testosterone performed poorly on memory tests.

It’s not just the hormones and their effects that differ between the sexes—it’s also the timeframe for hormonal surges. Behavioral neuroendocrinologist Irving Zucker, who detailed these differences in a 2017 study [PDF] in Biology of Sex Differences, tells Science News that females’ hormones vary more over a few days, while males’ vary more over the course of a single day.

There are also differences between the sexes that have nothing to do with hormones at all. In a 2015 study in eLife, Rebecca Shansky, a neuroscientist at Northeastern University, showed female and male rats a tone or light followed by a (harmless) shock to the feet. While all of the rats first learned to freeze after the signal, fearing the shock, some of the females responded to subsequent signals by racing around the cage—for no obvious hormonal reason. Shansky concluded that female rats may learn to process fear differently than males, suggesting that equality of the sexes among lab rats (at least in terms of studying them) can lead to more insightful results.

Plus, if male and female rats behave differently in a given situation, it’s possible that male and female humans would, too. (Perhaps unsurprisingly, human females have also frequently been excluded from clinical trials, including several important long-running studies on aging and other issues.)

And if you’re starting to feel like rats deserve more credit than you’ve previously given them, check out these other impressive rat facts.

[h/t Science News]

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