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When most people hear the word ammonite, they probably picture a small, spiral-shaped fossil that can fit comfortably in the palm of a hand.
But near Fernie, British Columbia, Canada, there is an ammonite that completely changes that image.
This extraordinary fossil is about 1.4 meters (4.6 feet) across—large enough to make the comparison to a tractor tire or truck tire seem surprisingly appropriate. It represents one of the most remarkable prehistoric fossils associated with the Fernie area.
And yes—it is real.
🐚 Imagine Seeing This Creature in the Jurassic Ocean
Around 150 million years ago, the landscape we now recognize as British Columbia looked dramatically different.
Parts of the region were covered by relatively shallow seas, and marine creatures lived where mountains, forests, and communities exist today. Among those animals were ammonites—extinct marine relatives of today’s cephalopods, the group that includes squid, octopuses, cuttlefish, and nautiluses.
The giant Fernie fossil has traditionally been identified as Titanites occidentalis, although more recent paleontological work has proposed the name Corbinites occidentalis for the giant western Canadian ammonite.
Whatever name is ultimately used, its size is what immediately captures people’s attention.
😲 A Fossil Described as a “Truck Tire”
The story of this remarkable fossil goes back to 1947, when a British Columbia Geological Survey field crew was mapping coal outcrops in the Coal Creek area.
A student had reported finding what was described as a “fossil truck tire.”
Imagine being out in the field expecting to find ordinary geological clues and suddenly encountering an enormous spiral fossil embedded in rock.
The discovery was so unusual because ammonites were marine animals, yet the fossil was found in an area that is now far from any ocean. That apparent contradiction is actually part of what makes fossils so fascinating: the landscape can change enormously over geological time.
🌊 British Columbia Was Once a Very Different Place
One of the most fascinating lessons from fossils isn’t simply what the animal looked like.
It’s what the surrounding rock tells us about Earth’s past.
The giant ammonites from the Fernie region lived in seas that covered parts of what is now British Columbia during the Late Jurassic. Over millions of years, geological processes transformed those ancient environments into the landscapes we see today.
So when someone stands beside the fossil today, they’re effectively looking at evidence from an ancient marine environment that disappeared long before humans existed.
🦑 What Was an Ammonite?
Ammonites were marine mollusks belonging to the cephalopod group.
Their closest living relatives include fascinating animals such as nautiluses, squid, and octopuses.
The most recognizable feature of an ammonite was its coiled shell. As the animal grew, it added new chambers to the shell, creating the distinctive spiral pattern that makes ammonite fossils so recognizable.
Although many ammonites were relatively small, the fossil record shows that some species reached impressive sizes.
The Fernie specimen is an extreme example.