How Long Does Something Have to Be In the Ground Before It's Considered a Fossil?

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Jelle Zijlstra:

The other answers here say that to be a fossil, something has to be mineralized in some way. The other answers are wrong.

At least, they don’t agree with common definitions in dictionaries and in paleontology. Usually, any remains or traces of an organism preserved in the ground are counted as fossils. People are less likely to use the term fossil for remains from the last 10,000 years (the Holocene, our geological period), but that is obviously arbitrary.

Here is the Oxford English Dictionary’s definition of fossil:

Something preserved in the ground, especially in petrified form in rock, and recognizable as the remains of a living organism of a former geological period, or as preserving an impression or trace of such an organism.

Especially in petrified form, not always in petrified form. They also say that “the term fossil is usually reserved for remains older than 10,000 years."

My textbook on paleobotany (Taylor et al., 2009, Paleobotany, Academic Press) doesn’t give a definition of the word fossil, but it does provide a nice catalog of the various kinds of plant fossils. Those include petrified wood, but they also include compression fossils, which are the result of the original plant material being compressed. No mineralization necessary. Pollen grains are a very common kind of plant fossil, and they are usually preserved unmineralized. Amber can isolate organic material sufficiently that it is preserved virtually unchanged.

Most paleontologists don’t discuss the definition of fossil, because it’s not terribly controversial. In one of my own papers I used the word for remains of the fossil rodent Cordimus hooijeri that are only a few hundred years old and not noticeably mineralized. Nobody called me out on it.

I did find one paper that explicitly discusses definitions: "A New Species of Fossil Ptinus from Fossil Wood Rat Nests in California and Arizona" (Coleoptera, Ptinidae), with a postscript on the definition of a fossil. This was in the context of beetles from woodrat middens, which were preserved as mostly unchanged exoskeletons. The author settled on “A specimen, a replacement of a specimen, or the work or evidence of a specimen that lived in the past and was naturally preserved rather than buried by man.” Again, no reference to mineralization. He discussed using the term fossil only for remains that are more than 10,000 years old; subfossil for remains before recorded history; and nonfossil for remains from recorded history. But that seemed arbitrary and unworkable; recorded history started at different times in different places.

Fossils are the remains of organisms of the past, regardless of their mode of preservation. Where exactly you draw the line between “organisms of the past” and “organisms of the present that just happen to be dead” is arbitrary and it usually doesn’t matter. If you need a definition (for example, if you’re making a list of fossil and nonfossil species), you come up with a reasonable if arbitrary definition. If you don’t need a precise definition, you don’t.

This post originally appeared on Quora. Click here to view.

Grocery Stores vs. Supermarkets: What’s the Difference?

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gpointstudio/iStock via Getty Images

These days, people across the country are constantly engaging in regional term debates like soda versus pop and fireflies versus lightning bugs. Since these inconsistencies are so common, you might have thought the only difference between a grocery store and a supermarket was whether the person who mentioned one was from Ohio or Texas. In reality, there are distinctions between the stores themselves.

To start, grocery stores have been around for much longer than supermarkets. Back when every town had a bakery, a butcher shop, a greengrocery, and more, the grocery store offered townspeople an efficient shopping experience with myriad food products in one place. John Stranger, vice president group supervisor of the food-related creative agency EvansHardy+Young, explained to Reader’s Digest that the grocer would usually collect the goods for the patron, too. This process might sound familiar if you’ve watched old films or television shows, in which characters often just hand over their shopping lists to the person behind the counter. While our grocery store runs may not be quite so personal today, the contents of grocery stores remain relatively similar: Food, drinks, and some household products.

Supermarkets, on the other hand, have taken the idea of a one-stop shop to another level, carrying a much more expansive array of foodstuffs as well as home goods, clothing, baby products, and even appliances. This is where it gets a little tricky—because supermarkets carry many of the same products as superstores, the next biggest fish in the food store chain, which are also sometimes referred to as hypermarkets.

According to The Houston Chronicle, supermarkets and superstores both order inventory in bulk and usually belong to large chains, whereas grocery stores order products on an as-needed basis and are often independently owned. Superstores, however, are significantly larger than either grocery stores or supermarkets, and they typically look more like warehouses. It’s not an exact science, and some people might have conflicting opinions about how to categorize specific stores. For example, Walmart has a line of Walmart Neighborhood Markets, which its website describes as “smaller-footprint option[s] for communities in need of a pharmacy, affordable groceries, and merchandise.” They’re not independently owned, but they do sound like grocery stores, especially compared to Walmart’s everything-under-the-sun superstore model.

Knowing the correct store terms might not always matter in casual conversation, but it could affect your credit card rewards earnings. American Express, for example, offers additional rewards on supermarket purchases, and it has a specific list of stores that qualify as supermarkets, including Gristedes, Shoprite, Stop & Shop, and Whole Foods. Target and Walmart, on the other hand, are both considered superstores, so you won’t earn bonuses on those purchases.

And, since grocery shopping at any type of store can sometimes seem like a competitive sport, here’s the ideal time to go.

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What Does CPR Stand For?

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undefined undefined/iStock via Getty Images

The life-saving technique known as CPR stands for cardiopulmonary resuscitation. It's a method that allows oxygenated blood to temporarily circulate throughout the body of a person whose heart has stopped. When the heart ceases beating during cardiac arrest, lungs stop receiving oxygen. Without oxygen, nerve cells start to die within minutes; it can take just four to six minutes for an oxygen-deprived person to sustain permanent brain damage or die.

The cardio part of the phrase refers to the heart, the muscular organ that pumps blood through the body's circulatory system. Pulmonary involves the lungs. People take approximately 15 to 20 breaths per minute, and with each breath you take, your lungs fill with oxygen. Resuscitation means bringing something back to consciousness, or from the brink of death.

We have two physicians, Peter Safar and James Elam, to thank for developing mouth-to-mouth resuscitation in the mid-1950s. In 1957, the American military adopted their CPR method for reviving soldiers. In 1960, the American Heart Association integrated chest compressions, which keep the blood circulating.

Doctors, nurses, dentists, first responders, lifeguards, and some teachers are required to be certified in CPR. But because approximately 85 percent of cardiac arrests occur at home, it’s smart for the average person to know how to perform it, too. In school, you were probably taught CPR by the traditional method of giving 100 to 120 chest compressions per minute (play the Bee Gees’ "Stayin’ Alive" in your head to keep the beat) and mouth-to-mouth resuscitation. Today, the American Heart Association recommends that average people learn hands-only CPR, which simply involves chest compressions. The organization has found that people can be reluctant to administer mouth-to-mouth CPR in an emergency because they're afraid of doing it wrong or injuring the patient. With hands-only CPR, bystanders feel less anxiety and more willingness to jump in. The AHA also notes that hands-only CPR can be just as effective in saving a life. (And any CPR is better than none at all.)

But how many people actually know CPR?

In 2018, a Cleveland Clinic survey found that 54 percent of Americans said they knew CPR, but only one in six people knew that bystander CPR requires only chest compressions. Only 11 percent of people knew the correct pace for compressions. Again, singing "Stayin' Alive" to yourself is one way to remember the pace—though being a fan of The Office can apparently help, too (as one lucky life-saver recently discovered).

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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