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10 Terrific Facts About Trilobites

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For nearly 300 million years, these ancient mariners dotted our ocean floors—surviving, thriving, and fossilizing beneath the waves.

1. OVER 20,000 SPECIES ARE CURRENTLY KNOWN.

Every single continent has yielded trilobite remains. The biggest species (Isotelus rex) was some 28 inches long, while the smallest measured less than a millimeter from end to end. Some sported defensive spines, while others had smooth, rounded shells. And whereas certain trilobites came with disproportionately large eyes, many deep-sea species were blind.

2. TRILOBITES FIRST APPEARED AROUND 540 MILLION YEARS AGO.

Their debut roughly coincided with the dawn of the Cambrian period. During this game-changing chapter in Earth’s history, multi-celled organisms went through an apparent explosion in diversity, or at least an explosion in life forms that leave fossils. New creatures—including a barrage of mollusks and arthropods—seem to have evolved at an unprecedented rate.

The Cambrian also saw trilobites become the most common and diverse animals on the planet. However, trilobites began to decline when the period ended some 500 million years ago. Though the invertebrates stuck around for another 240 million years, they’d never again be so successful.

3. MANY WOULD CURL UP INTO LITTLE BALLS FOR PROTECTION.

When danger struck, some trilobites could ball themselves up like underwater pill bugs, with their rear end flexed under their head. Specimens dating as far back as the late Cambrian have been found in this defensive position. 

4. AT FIRST, SCIENTISTS DIDN’T KNOW WHAT TO MAKE OF THEM.

Fæ, Wikimedia // Public domain

In a 1679 letter, Welsh linguist and naturalist Edward Lhuyd misidentified one as “the sceleton [sic] of some Flat-fish.” Bishop Charles Lyttleton came a little closer to the mark in 1750 when he wrote London’s Royal Society about a “petrified Ins[e]ct” that he’d dug up a year before. While trilobites were, in fact, arthropods, the creatures appear to have been more closely akin to crustaceans and/or chelicerates (i.e. arachnids and horseshoe crabs) than insects.

5. MOST TRILOBITE FOSSILS ARE ACTUALLY MOLTED EXOSKELETONS.

ellenm1,Wikimedia // CC BY 2.0

Over the course of its life, a trilobite outgrew many shells. During the molting process, these discarded husks would often get preserved for posterity. One trilobite could therefore leave behind several trilobite-shaped fossils. Specimens that represent the actual creature—as opposed to its shuffled-off shell—are comparatively rare

6. THREE STATES HAVE MADE A TRILOBITE THEIR OFFICIAL FOSSIL.

JMCC1, Wikimedia // CC BY-SA 3.0 

In 1985, Ohio chose the entire Isotelus genus and Wisconsin went with Calymene celebra. Three years later, Pennsylvania picked Phacops rana after an elementary school class lobbied for its appointment.

 7. TRILOBITES GATHERED FOOD IN A VARIETY OF WAYS.

Generally speaking, early trilobites seem to have hunted down aquatic worms and eaten them alive. It’s been theorized that a few other species evolved to eat plankton or algae—with some making use of a filter-feeding mechanism.

8. TRILOBITES WERE WIPED OUT BY THE BIGGEST EXTINCTION IN HISTORY.

NASA/JPL-Caltech/UCLA (WISE),Wikimedia Commons

Some call it the "Great Dying”—250 million years ago, 90 percent of all species on earth suddenly perished. Possible causes include everything from increased volcanic activity to exploding supernovas. Regardless, the event—also known as the Permian Extinction—killed off a number of insects, sharks, armored fish, mammal-like creatures, and countless other organisms. Trilobites, however, are by far the most famous lineage to have met their end this way.  

9. NATIVE AMERICANS USED THEM AS AMULETS.

Long before Europeans first set foot on the continent, the Pahvant Ute people, from what is now called Utah, gathered Cambrian trilobites. Believing that the fossils harbored special powers, the natives carried them around as protective charms. These odd, petrified critters were given the name “Timpe-Konitza-Pachuee,” or “little water bug living in a house of stone.”

10. ONE CHINESE TRILOBITE WAS NAMED AFTER A STAR WARS CHARACTER.

Dwergenpaartje, Wikimedia // CC BY-SA 3.0

Around the start of the last decade, paleontologist Samuel Turvey happened upon several new species of trilobites while exploring in China. He gave one new invertebrate the genus name Han, which it shares with China’s biggest ethnic group. When the time came to pick species names, Turvey couldn’t resist bolstering his Star Wars cred, and named one particular trilobite Han solo. (It helped that Han solo was the only species in the genus.)

All photos courtesy of iStock unless otherwise noted. 

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The Simple Way to Protect Your Dog From Dangerous Rock Salt
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Winter can be a tough time for dogs. The cold weather usually means there are fewer opportunities for walks and more embarrassing accessories for them to wear. But the biggest threat to canines this time of year is one pet owners may not notice: the dangerous rock salt coating the streets and sidewalks. If you live someplace where this is a problem, here are the steps you need to take to keep your pooch safe until the weather warms up, according to Life Hacker.

Rock salt poses two major hazards to pets: damage to their feet and poisoning from ingestion. The first is the one most pet owners are aware of. Not only do large grains of salt hurt when they get stuck in a dog’s paws, but they can also lead to frostbite and chemical burns due to the de-icing process at work. The easiest way to prevent this is by covering your dog’s paws before taking them outside. Dog booties get the job done, as do protective balms and waxes that can be applied directly to their pads.

The second danger is a little harder to anticipate. The only way you can stop your dog from eating rock salt from the ground is to keep a close eye on them. Does your dog seem a little too interested in a puddle or a mound of snow? Encourage them to move on before they have a chance to take a lick.

If, for some reason, you forget to follow the steps above and your pet has a bad encounter with some winter salt, don’t panic. For salty feet, soak your dog's paws in warm water once you get inside to wash away any remaining grit. If your dog exhibits symptoms like vomiting, diarrhea, and disorientation and you suspect they’ve ingested rock salt, contact your vet right away.

Even with the proper protection, winter can still create an unsafe environment for dogs. Check out this handy chart to determine when it’s too cold to take them for a walk.

[h/t Life Hacker]

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© Museum of Fine Arts, Boston
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Boston's Museum of Fine Arts Hires Puppy to Sniff Out Art-Munching Bugs
© Museum of Fine Arts, Boston
© Museum of Fine Arts, Boston

Some dogs are qualified to work at hospitals, fire departments, and airports, but one place you don’t normally see a pooch is in the halls of a fine art museum. The Museum of Fine Arts, Boston is changing that: As The Boston Globe reports, a young Weimaraner named Riley is the institution’s newest volunteer.

Even without a background in art restoration, Riley will be essential in maintaining the quality of the museum's masterpieces. His job is to sniff out the wood- and canvas-munching pests lurking in the museum’s collection. During the next few months, Riley will be trained to identify the scents of bugs that pose the biggest threat to the museum’s paintings and other artifacts. (Moths, termites, and beetles are some of the worst offenders.)

Some infestations can be spotted with the naked eye, but when that's impossible, the museum staff will rely on Riley to draw attention to the problem after inspecting an object. From there, staff members can examine the piece more closely and pinpoint the source before it spreads.

Riley is just one additional resource for the MFA’s existing pest control program. As far as the museum knows, it's rare for institutions facing similar problems to hire canine help. If the experiment is successful, bug-sniffing dogs may become a common sight in art museums around the world.

[h/t The Boston Globe]

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