8 Ancient Writing Systems That Haven't Been Deciphered Yet

The Indus Valley civilization was one of the most advanced in the world for more than 500 years, with more than a thousand settlements sprawling across 250,000 square miles of what is now Pakistan and northwest India from 2600 BCE to 1900 BCE. It had several large, well-planned cities like Mohenjo-daro, common iconography—and a script no one has been able to understand. 

Over at Nature, Andrew Robinson looks at the reasons why the Indus Valley script has been so difficult to crack, and details some recent attempts to decipher it. Since we don't know anything about the underlying language and there's no multilingual Rosetta stone, scholars have analyzed its structure for clues and compared it to other scripts. Most Indologists think it's "logo-syllabic" script like Sumerian cuneiform or Mayan glyphs. But they disagree about whether it was a spoken language or a full writing system; some believe it represented only part of an Indus language, Robinson writes. 

One team has created the first publicly available, electronic corpus of Indus texts. Another, led by computer scientist Rajesh Rao, analyzed the randomness in the script's sequences. Their results indicated it's most similar to Sumerian cuneiform, which suggests it may represent a language. Read the full article for more details.   

The Indus Valley script is far from the only one to remain mysterious. Here are eight others you might try your hand at deciphering.

1. Linear A

In 1893, British archaeologist Sir Arthur Evans purchased some ancient stones with mysterious inscriptions on them at a flea market in Athens. On a later trip to the excavations at Knossos on the island of Crete, he recognized one of the symbols from his stones and began a study of the engraved tablets being uncovered at various sites on the island. He discovered two different systems, which he called Linear A and Linear B. While Linear B was deciphered in the early 1950s (it turned out to represent an early form of Greek), Linear A, above, has still not been deciphered.

2. Cretan Hieroglyphics

The excavations on Crete also revealed a third type of writing system, with symbols that looked more picture-like than those of the linear scripts. Some of these symbols are similar to elements in Linear A. It is assumed that the hieroglyphic script developed into Linear A, though the two systems were both in use during the same time period.

3. Wadi el-Hol script

In the 1990s, a pair of Yale archaeologists discovered a graffiti-covered cliff wall at the Wadi el-Hol (Gulch of Terror) in Egypt. Most of the inscriptions were in systems they could recognize, but one of them was unfamiliar. It looks like an early transition from a hieroglyphic to an alphabetic system, but it hasn't yet been deciphered.

4. Sitovo inscription

In 1928 a group of woodcutters found some markings carved into a Bulgarian cliffside. They thought the marks indicated hidden treasure, but none was found. Word got around and soon some archaeologists had a look. Later, the head of the expedition was executed for being a secret agent for the Soviets in Bulgaria. One piece of evidence used against him was a strange coded message he had sent to Kiev—actually a copy of the cliffside inscription he had sent to colleagues for scholarly input. It is not clear what language the inscription represents. Thracian, Celtic, Sarmato-Alanian, and Slavic are some of the possibilities scholars have argued for. Another suggestion is that it's simply a natural rock formation.

5. Olmec writing

The Olmecs were an ancient Mexican civilization best known for the statues they left behind: the so-called "colossal heads." In 1999, their writing system was revealed when road builders unearthed an inscribed stone tablet. The tablet shows 62 symbols; some look like corn or bugs, and some are more abstract. It has been dated to 900 B.C., which would make it the oldest example of writing in the Western Hemisphere.

6. Singapore stone

There once was a giant engraved slab made of sandstone at the mouth of the Singapore River. It had been there for 700 years or so when, in 1819, workers uncovered it while clearing away jungle trees. A few scholars got a look at it before it was blown to bits in order to make space for a fort to protect the British settlements. The parts that didn’t end up in the river were eventually used for road gravel, though some fragments were saved. The script hasn't been deciphered, but there have been various suggestions for what language it might represent: ancient Ceylonese, Tamil, Kawi, Old Javanese, and Sanskrit.

7. Rongorongo

When missionaries got to Easter Island in the 1860s, they found wooden tablets carved with symbols. They asked the Rapanui natives what the inscriptions meant, and were told that nobody knew anymore, since the Peruvians had killed off all the wise men. The Rapanui used the tablets as firewood or fishing reels, and by the end of the century they were nearly all gone. Rongorongo is written in alternating directions; you read a line from left to right, then turn the tablet 180 degrees and read the next line.

8. Proto-Elamite

Marie-Lan Nguyen via Wikimedia Commons // CC BY 2.5

This ancient writing system was used more than 5000 years ago in what is now Iran. Written from right to left, the script is unlike any other ancient scripts; while the proto-Elamites appear to have borrowed the idea for a written language from their Mesopotamian contemporaries, they apparently invented their own symbols—and didn't bother to keep track of them in an organized way, proto-Elamite expert and Oxford University scholar Jacob Dahl told the BBC in 2012. Around that time, he and his Oxford colleagues asked for help from the public in deciphering proto-Elamite. They released high-quality images of clay tablets covered in Proto-Elamite, hoping that crowdsourcing could decode them. Now a collaboration involving several institutions, the project is ongoing

What's the Difference Between Tequila and Mezcal?


Aside from tacos, enchiladas, and other tasty tortilla-wrapped treats, tequila and mezcal are among some of Mexico’s best-known offerings in the food and beverage category. These tipples, made from the agave plant, are so embedded in the country’s culture that Mexico City even has a museum dedicated to the two drinks, and Jose Cuervo operates a "tequila train" to none other than the city of Tequila. These beverages can be used to make a variety of cocktails, from the tequila sunrise to the mezcalita, but unless you’re a bartender or a connoisseur of spirits, you might not know the difference between the two. Is mezcal just fancier tequila?

Not exactly. Tequila is a type of mezcal, but the reverse isn’t always true. It’s similar to the distinction between champagne and sparkling wine, in which the name of the beverage depends on whether it was produced in the Champagne region of France or elsewhere. While mezcal can be produced anywhere in Mexico, tequila is made in the Mexican state of Jalisco (though a few exceptions do apply).

Tequila and mezcal also differ in the ingredients from which they are derived. Mezcal can come from any of the dozens of agave plants—a type of desert succulent—that are grown throughout Mexico. Tequila is made specifically from blue agave and, depending on the variety and brand, a bottle will contain between 51 percent and 100 percent of the plant-based nectar. According to The Tierra Group, a wholesaler of agave products, blue agave nectar is especially sweet because it’s 80 percent fructose, per Mexico’s regulations.

Lastly, tequila and mezcal taste different because of the ways in which they are prepared. Mezcal tends to have a savory, smoky, earthy flavor because the agave hearts (or piñas) are left cooking for several days in a fire pit that has been lined with volcanic rock and covered with agave leaves and earth. The piñas destined to end up in tequila, on the other hand, are often cooked in a brick oven, then crushed up to extract the juice.

If you ever feel adventurous at the liquor store and decide to bring home a bottle of mezcal, just keep in mind that there’s a particular way to drink it. “The first mistake many people make is pouring mezcal in a shot glass and pouring it down their throat,” Chris Reyes, a mixologist at New York City’s Temerario bar and restaurant told Liquor.com. Instead, the spirit is best sipped in a clay cup known as a jicarita.

Some words of advice if you do go shopping for mezcal: If you ever see a worm at the bottom of the bottle, that means it’s probably not a very good mezcal, according to Reyes. By contrast, tequila bottles should never have worms in them (despite the common misconception). So if you’re looking to avoid invertebrate-infused concoctions at all costs, tequila is your best bet.

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

15 Animal Names That Can Be Used As Verbs


People can go fishing, rabbit on incessantly, dog one another, and horse around. But because of their usefulness in completing burdensome work, horse has also been used in (originally naval) slang since the mid-19th century to mean “to work to the point of exhaustion”—or, in the words of the Oxford English Dictionary, “to drive or urge at work unfairly or tyrannically.” But horses aren’t the only animals whose names can be “verbed.” From turtles to tigers, you can drop any one of these 15 creatures into your everyday conversation.

1. Bulldog

No one is entirely sure why bulldogs are called bulldogs, with different theories pointing to everything from their bull-like stature to their bullish faces to the fact that they might once have been bred to bait bulls. Whatever the origin, the bulldog’s strength and its robust, resilient behavior means that you can use its name as a verb meaning “to attack roughly,” or “to wrestle to the ground.”

2. Tiger

A tiger

If you tiger, then you walk to and fro, like a tiger pacing in a cage. If you tiger something, then you paint or mark it with contrasting stripes.

3. Spider

Jumping spider

As well as being used simply to mean “to creep” or “to move like a spider,” if you ensnare or entrap something, or else cover it in a cobweb-like pattern, then you spider it.

4. Cat

British shorthair cat with expressive orange eyes

Because the cathead is the horizontal beam at the bow of a ship that’s used to raise an anchor, the word cat has a number of nautical uses as a verb, including “to lift an anchor from the water,” “to secure an anchor,” and “to draw an anchor through the water.” But because shooting the cat was 19th century slang for being sick from drinking too much, you can also use cat to mean “to vomit.”

5. Vulture

White-backed vulture

Vultures’ grim feeding habits and their remarkable flying ability have given the word two meanings as a verb in English. Feel free to use it to mean “to eat voraciously” or “to tear at your food,” or else “to descend steadily through the air.”

6. Owl

Owl in flight

Owling (as well as being a short-lived social media craze) was once the name given to the crime of smuggling sheep and wool from England to the continent—a crime so-called because the nefarious “owlers” carried out their crimes at night. That might not be the most useful of words these days of course, so feel free to also use owl to mean “to act wisely, despite not knowing anything.”

7. Shark

It’s easy to presume that the use of shark as a verb to mean “to act like a predator” (which is the same shark as in loanshark, incidentally) derives from the deadly sea creatures. In fact, it might be the opposite: Both meanings of the word shark date back to the late 16th century, but it’s possible that the verb shark is the older of the two. If so, it’s possible that it comes from the earlier word shirk (in the sense of using deceit or trickery to avoid work) or else a northeastern French word, cherquier, which was often used in a phrase that essentially meant “to sponge of others” or “to act as a parasite.” So how did sea-dwelling sharks come to be called sharks? It’s possible the deceitful sharks gave their name to the menacing creatures, or else the two could be completely unrelated—and, thanks to a sea battle off the Yucatan peninsula in 1569, shark could in fact be a Mayan word.

8. Monkey

Chimpanzee looking surprised

As well as meaning “to play the fool” or “to behave playfully”—as in “monkeying around”—monkey, like ape, can also be used to mean “to mimic” or “to copy someone’s movements or actions.”

9. Turtle

If a boat “turns turtle,” then it capsizes and flips over, so that it looks like a turtle’s domed shell floating atop the water. Because of that, to turtle something is to turn it upside down.

10. Snail

Burgundy snail

For obvious reasons, snail has been used to mean “to move slowly” since the late 16th century, but because of the snail’s coiled shell, you can also use snail to mean “to draw or carve a spiral,” or “to roll into a spiral shape.”

11. Porcupine

Porcupine walking

When your hair stands on end, feel free to say that it porcupined.

12. Canary

Canary birds take their name from the Canary Islands, which, somewhat confusingly, take their name from canis, the Latin word for “dog.” But in the 16th and 17th centuries, the canary was also the name of an energetic dance inspired by a traditional dance performed by the natives of the Canary Islands. And because of that, you can also use the word canary as a verb meaning “to dance in a lively fashion.”

13. Earwig


Earwigs are so-called because they were once (thankfully erroneously) thought to crawl inside people’s ears as they slept. Through association with someone whispering clandestinely into someone’s ear, in the late 18th century eavesdroppers and people who seeked to secretly influence others became known as earwiggers—and so to earwig is to do precisely that.

14. Pig

Cute pig leaning on railing of his cot

Pig has been used to mean “to give birth” since as far back as the 15th century in English (a fairly uncomplimentary allusion to a pregnant sow delivering a litter of piglets). But slightly less depreciatively, the living habits of pigs mean that it can also be used to mean “to huddle together,” or else “to live or sleep in crowded or dirty conditions.”

15. Dingo

A dingo

Because of their stereotypically sneaky behavior, to dingo on someone meant “to let down” or “to betray” them in 1930s Australian slang, while to dingo meant simply “to shirk” or “to back out of something at the last minute.”

This list first ran in 2016.