Blast from the Past: Buying Ammonites & What You Need to Know About These Fossils


It’s common to see fossils in museum, but did you know that you can actually by fossils online? There are some legitimate online stores that sell authentic fossils ranging from dinosaur bones to insect specimens trapped in amber. I found websites such as FossilEra, Fossil Shack, Paleo Direct, and The Fossil Store. I even found legitimate fossil sellers on EBay and Amazon.

One type of fossil that caught my attention while browsing through websites was the ammonite fossil. In some photos, these fossils had a diameter of two or three inches, while in other photos, there were some that were bigger than an average head. There were even bigger than the average human person.

With its unique formation and interesting history, casual fossil collectors may want to have an ammonite fossil in their collection. In this article, we discuss everything you need to know about ammonite fossils if you’re curious to learn more about it and its purpose in marine life before extinction.


What Is an Ammonite Fossil?

Ammonite fossils come from ammonites or ammonoids, a type of Ammonoidea, which is a subset of Cephlopoda or cephalopods. The term “ammonite” comes from the Egyptian god Ammon (Amun), who supposedly wore ram horns.

These were mollusks that resembled squid or octopuses and are a close relative of these animals we have today. However, unlike squid or octopuses, ammonites had a hard shell that protected their body which was soft and filled with tissue and vital organs.

Ammonites originated from cephalopods called bacrites. They first appeared around 240 million years ago, during the Devonian period during the Paleozoic era. Ammonites bred frequently and lived in schools, which is why there were abundant fossils clumped in groups. Based on fossils, their sizes varied, from small ammonites that were around an inch long, to shells that were many feet long.


Not much can be confirmed about its way of life as ammonites and its closest relatives did not survive the extinction. However, scientists can theorize how ammonites survived for millions of years based on the life and nature of its surviving relatives and other inferences they can make from found fossils.

Ammonites were carnivores that fed on plankton. Because of its close relation to squid and ink preserved on its fossils, it is believed that they have the same defense mechanism of squirting ink at predators. The softest part of the ammonites’ bodies were kept at the end of the coil, and the air inside the shell allowed them to stay afloat. They used a sort of biological pump and siphoning system in their bodies to control the gas and fluids inside their shells.

Lifespan and Reproduction

Unlike other cephalopods, ammonites had a different kind of reproduction that led to several near-extinction way before the mass extinctions. Before they die, ammonites release a number of eggs in the water where there was plankton. Female ammonites experienced sexual dimorphism, which meant they had both female and male sexual organs.

Ammonites built their shells as they grew. Their septa and the rest of the shell helped in terms of buoyancy, but the ammonites themselves only lived on the outer chamber by hiding the softest parts of their bodies in the shell. To move, they would shoot jets of water from their body. They had a thin tube called a siphuncle that pumped air to help them navigate through the water.


How Old Are Ammonite Fossils?

The ammonites continued to be a common part of the marine ecosystem from the Devonian period around 420 up to 360 million years ago until the end of the Mesozoic era as well as the Cretaceous period 66 million years ago.

When Did the Ammonites Become Extinct?

The ammonites were one of the octopuses and squids’ relatives to go extinct after the Cretaceous-Paleogene extinction event. It was strongly believed that an asteroid that hit Earth caused the mass extinction of plant and animal species 66 million years ago. Some ancestors of mollusks and cephalopods survived and evolved into the snails, octopuses, and bivalves we know today, but it was likely that the ammonites did not survive.

We can’t know this for sure because a huge portion of the bottom of the ocean remains unexplored. But this may be unlikely, as ammonite fossils were never found with other fossils of creatures that lived at the bottom of the seas and oceans at the time. However, millions of ammonite shells were preserved and, today, are common findings in fossil searches.

Ammonite Fossils and Sizes

Aside from protecting the soft parts, its shells were meant to be filled with gasses or fluids. Around the early Jurassic period, its sizes would range an average of 9 inches (53 cm) up to 6.5 feet (2 meters), which is the largest ammonite found in Europe. The largest ammonite fossil found in North America was from the Cretaceous era, measuring 4.5 feet (137 cm). It was believed that females were bigger creatures compared to their male counterparts.

Suture Patterns

There were various types of ammonites from the Devonian up to the Cretaceous period. Some researchers considered these orders to be Agoniatitida, Clymeniida, Goniatitida, Prolecanitida, Ceratitida, and Ammonitida, but others would classify most of these categories as sub-orders instead of order, and the three orders were limited to Goniatitida, Ceratitida, and Ammonitida. Scientific researchers could separate which of the orders found fossils belonged to based on the suture patterns left on the fossils.

Goniantitic sutures had eight lobes and have many undivided lobes. Ceratitic ammonites had round and undivided saddles with a saw-toothed lobe appearance. And Ammonitic ammonites had fluted and rounded lobes that are subdivided. By looking at these features, researchers can estimate how old the fossils were.


Ammonite fossils were found around the time of the Roman Empire, as its name is attributed to Pliney the Elder, who decided to name it after the Egyptian god and the fossil’s similarity to the shape of a tightly coiled rams’ horns.

In medieval Europe (from 476 up to 1500), ammonite fossils were thought to be snakes that were turned into stone and were called “snakestones” or, later in medieval England, “serpentstones.” Hilda of Whitby, a Christian saint from Anglo-Saxon England, used ammonite fossils as proof of the miracles she had performed. Legend has it, there was a plague of snakes, and Hilda managed to turn them into stone, which is why ammonite fossils were found on the shore. To commemorate Saint Hilda, artists would carve snake heads onto fossils. Today, an ammonite fossil is set on a wall at the College of St. Hild and St. Bede in the University of England.

Saint Patrick, a Christian missionary from Ireland, also claimed to have healing powers, using ammonite fossils to prove his healing and oracular powers. Ammonite fossils found in the Gandaki River in Nepal were considered “saligrams,” which were fossilized shells that Hindus believed were a sign from the god Vishnu. Ammonites were also once considered to be charms that protect people against serpents, baldness, and infertility.

Buying Ammonite Fossils

Ammonites are fairly common and not as expensive compared to fossils such as dinosaur bones, but they’re still pretty rare. Some ammonites can be fairly expensive depending on several factors. These factors can include its specific species, what era or period it was from, where it was found, its size, and how intact it is.

In 2014, Christie’s auctioned an ammonite in France worth a little over $62,000, but the most valuable one they auctioned off was one in 2009 worth around $72,000 but only sold from about $43,000. Outside of valuable auctions, you can usually find ammonites for sale with prices as low as $3 up to almost $2000. Preserved ammonites left as is or in-lined with minerals may be more expensive, while smaller ammonites turned into buttons, keychains, or other common ammonite shapes sold in bulk are much cheaper.

Source: Nature’s Art Village

Is Authenticity Guaranteed?

Like diamonds and gold, it’s possible for sellers to fake ammonites. So, be careful with fossil sellers selling mid- to high-range ammonite fossils, as some may scam you with replicas or fake products that are worth less than the price you bought it for. There are some ways to ensure that the ammonite you are buying is authentic.

Find an Established Seller with Organizational Ties

While there are some genuine sellers on EBay and Amazon, I wouldn’t recommend buying high-priced fossils there because of the risk. If you’re buying online, do your research about the seller. It helps if they have a website of their own, have reviews, and known fossil collectors can vouch for their authenticity. In some cases, they may be a member of paleontological groups, such as the Association of Applied Paleontological Science.

Seller Can Be Easily Contacted

A scammer may be difficult to contact once they’ve received payment. Legitimate fossil collectors and online stores, however, are not afraid of you finding out where you can contact them or where they operate because they are a legitimate business. Before making a purchase, read up on their contact info and make sure it’s working, see if they have a headquarters.

Mentioned in the Media

A relatively unknown seller would not be featured in the media. But if a reliable news source did a feature on a store, then it’s highly likely that they’ve done their own thorough research and found that it was a legitimate store. If you research the store and find it on authentic news sites, unless the article is about fraud or fake fossils, then you can bet that they’re a genuine business.

Has an Authenticity Guarantee

This sign can be tricky as any business can say they have a guarantee, but then refuse to honor their guarantee after a purchase. However, if you can find a detailed guarantee ensuring what you can do if you find that your fossil is fake (together with contact information), you can ensure that what you are getting is legitimate.

Legitimate authenticity guarantees will often have return policies (like with other products sold online). You may also ask for a Certificate of Authenticity, especially for highly valuable fossils.

Look at Their Repair and Restoration

Finding fossils are not just a treasure hunt; sometimes, it’s also like finding a puzzle, and sometimes the pieces are incomplete. In many occasions, fossils are found incomplete or broken and need to be repaired. When done correctly, the repairs are invisible and enhances the value of the fossil.

However, look out for signs of restoration. Repair is putting the pieces together to improve the value, but restoration is replacing a part of the ammonite shell that may have been chipped by time or through transport, and the seller simply forged a piece similar to the crack and attached it. It may look better than a cracked ammonite fossil, but its value is significantly less when it’s restored.

Ammonites are one of the more common fossils on the market, but large and rare-looking specimens can cost collectors thousands of dollars. Aside from their interesting and unique appearance, they are a great indicator about the time period the rest of the fossils around them indicate. It’s also very interesting comparing the history of mollusks and cephalopods with the specimens still alive today.

If you’re interested in buying one, though, make sure you’re spending your money on an authentic piece. Fake ammonites and ammonites that have been restored are worth less than the high prices put on large pieces or ammonite fossils dating back to earlier periods. Make sure you’re purchasing the right ammonite fossil by only dealing with legitimate sellers who can verify the authenticity of their fossils.


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