How common are ammonite fossils?

Ammonite Fossils: How Easy Are They to Find, Really?

Okay, ammonites. Those cool, swirly fossils that look like something straight out of a Jules Verne novel. Ever wondered how often people actually find them? Are we talking rare-as-hen’s-teeth treasures, or are they more like, “Oh, another ammonite,” common? Well, it’s complicated, but generally speaking, you’re more likely to stumble across one than, say, a complete T-Rex skeleton.

Think of it this way: while finding a perfectly preserved, rainbow-sheened ammonite is like winning the lottery, finding an ammonite fossil? That’s a bit more achievable.

Deep Time and Lots of Ammonites:

These guys were around for a long time – over 340 million years! They partied in the oceans from the Early Devonian Period (that’s, gulp, 410 million years ago) right up to the Cretaceous, when the dinosaurs checked out (66 million years ago). That’s most of the Mesozoic Era, the heyday of reptiles. And because they were around for so long, and spread out everywhere, their fossils are, well, relatively abundant.

Why So Many Fossils? Let’s Break It Down:

So, what made them so good at becoming fossils? A few things:

• They were everywhere: Seriously, the oceans were teeming with them. Scientists figure there were over 10,000 different types!
• Tough Shells: Like the nautilus you might see in an aquarium, they had hard shells made of stuff called aragonite. Think of it as nature’s body armor and buoyancy device all in one. Hard shells preserve way better than soft squidgy bits.
• Good Burial Practices (Accidentally): Quick burial in sediment is key to fossilization. Luckily for us, the ocean floor can be pretty good at providing that, protecting them from being munched on by scavengers and creating the right chemical soup for fossilization.
• Geologists Love Them: Ammonites are what we call “index fossils.” Basically, they evolved so quickly that different species only lived for short periods. This means if you find a particular ammonite, you know roughly how old the rock around it is. Geologists use them to date rocks all over the world, which means a lot of ammonites get found and cataloged.

Where to Find Your Own (Maybe):

Ammonites have turned up all over the globe, especially in sedimentary rocks that used to be ocean floors. Here are a few hotspots:

• Europe: Places like the south of England are famous for their Jurassic and Cretaceous rocks, which are stuffed with ammonites.
• The Americas: Head to the prairies of Alberta, Canada, or the Cretaceous rocks of western Kansas. You might get lucky. Even New Jersey has some cool marine fossils, including ammonites. Who knew?
• Africa: Madagascar, specifically the Tsaratanana Formation, is another great place to look.
• Asia: Keep your eyes peeled; they’re out there!

But Some Are Rarer Than Others…

Okay, so most ammonites aren’t going to make you rich. But some… well, that’s a different story. Here’s what makes an ammonite extra special:

• Completeness is Key: A whole, undamaged ammonite is way cooler (and rarer) than a broken fragment.
• Shiny and New (Well, Old, But You Know…): If the fossil still has its original pearly shine, hold on to it! Those iridescent ones are pretty special.
• Size Matters: While they came in all sizes, finding a giant one – we’re talking dinner-table-sized – is pretty unusual.
• Weird Shapes: Most ammonites are coiled, but some went a bit crazy and evolved into weird, uncoiled shapes called heteromorphs. These oddballs are definitely rare.
• Ammolite Gold: In Canada, those shiny ammonites can be turned into a gemstone called ammolite. Cha-ching!

The Bottom Line:

Ammonites are common enough that geologists rely on them to date rocks. But finding a spectacular ammonite? That’s a different ballgame. Whether you find a common-as-muck fragment or a museum-worthy masterpiece, holding an ammonite fossil is like shaking hands with a creature from millions of years ago. And that’s pretty darn cool.