A MASSIVE AMMONITE THE SIZE OF A CAR: THE FERNIE AMMONITE

Titanites occidentalis, Fernie Ammonite

The Fernie ammonite—long known as Titanites occidentalis—has officially been given a new name: Corbinites occidentalis, a fresh genus erected after a meticulous re-evaluation of this Western Giant’s anatomy and lineage. 

What hasn’t changed is its breathtaking presence high on Coal Mountain near Fernie, British Columbia, where this colossal cephalopod has rested for roughly 150 million years.

This extraordinary fossil belongs to the family Lithacoceratinae within the ataxioceratid ammonites. 

Once thought to be a close cousin of the great Titanites of Dorset, new material—including two additional large specimens discovered at nearby mine sites—reveals ribbing patterns and growth-stage features that simply didn’t match Titanites. 

With these multiple overlapping growth stages finally available, paleontologists had the missing pieces needed to correct its identity.

So, Titanites occidentalis no more—meet Corbinites occidentalis, a giant ammonite likely endemic to the relatively isolated early Alberta foreland basin of the Late Jurassic.

Fernie, British Columbia, Canada

The Fernie ammonite is a carnivorous cephalopod from the latest Jurassic (Tithonian). 

The spectacular individual on Coal Mountain measures 1.4 metres across—about the size of a small car tire and absolutely staggering when you first see it hugged by the mountainside.

The first specimen, discovered in 1947 by a British Columbia Geophysical Society mapping team at Coal Creek, was initially mistaken for a “fossil truck tire.” 

Fair enough—if a truck tire had been forged in the Jurassic and left on a mountaintop. It was later described by GSC paleontologist Hans Frebold, who gave it the name Titanites occidentalis, inspired by the giant ammonites of Dorset. 

For decades, that name stuck, even though paleontologists suspected the attribution was shaky due to poor preservation of the holotype’s inner whorls.

Recent discoveries of two additional specimens at Teck Resources’ Coal Mountain Mine finally provided the evidence needed for reassessment. 

With intact inner whorls and beautifully preserved ribbing—including hallmark variocostate and ataxioceratoid ornamentation—researchers Terence P. Poulton and colleagues demonstrated that the Canadian ammonite does not belong in Titanites. 

Their work (Volumina Jurassica, 2023) established Corbinites as a brand-new genus, with C. occidentalis as its type and only known species.

These specimens—one exceeding a metre, another about 64 cm—confirm a resident ammonite population within this basin. And as of now, these giants are unique to Western Canada.

A Journey Up Coal Mountain

If you’re keen to meet Corbinites occidentalis in the wild, you’ll want to head to Fernie, in southeastern British Columbia, close to the Alberta border. 

As your feet move up the hillside, you can imagine this land 10,000 years ago, rising above great glaciers. Where footfalls trace the steps of those that came before you. This land has been home to the Yaq̓it ʔa·knuqⱡi ‘it First Nation and Ktunaxa or Kukin ʔamakis First Nations whose oral history have them living here since time immemorial. Like them, take only what you need and no more than the land offers — packing out anything that you packed in. 

Active logging in the area since 2021 means that older directions are now unreliable—trailheads have shifted, and a fair bit of bushwhacking is the price of admission. Though clear-cutting reshaped the slope, loggers at CanWel showed admirable restraint: they worked around the fossil, leaving it untouched.

The non-profit Wildsight has been championing efforts to protect the ammonite, hoping to establish an educational trail with provincial support and possible inclusion under the Heritage Conservation Act—where the fossil’s stewardship could be formally recognised.

HIKING TO THE FERNIE AMMONITE (IMPORTANT UPDATE: TRAIL CLOSED)

From the town of Fernie, British Columbia, you would traditionally head east along Coal Creek Road toward Coal Creek, with the ammonite site sitting 3.81 km from the road’s base as the crow flies. 

The classic approach begins at a roadside exposure of dark grey to black Cretaceous plant fossils, followed by a creek crossing and a steep, bushwhacking ascent.

However — and this is critical — the trail is currently closed.

The entire access route runs straight through an area of active logging, and conditions on the slope are extremely dangerous. Between heavy equipment, unstable cutblocks, and altered drainages, this is not a safe place for hikers right now.

Conservation groups, including Wildsight, continue working toward restoring safe public access and formalising the site under the Heritage Conservation Act. 

Their long-term goal is to reopen the trail as a designated educational hike with proper signage, but at present, the route should not be attempted. 

Once logging operations move out of the area and safety assessments are done, the possibility of reopening may return.

For now, the safest—and strongly recommended—way to view this iconic fossil is via the excellent cast on display at the Courtenay & District Museum on Vancouver Island, or at the Visitor Information Centre in Sparwood.

Photo credit: Vince Mo Media. Vince is an awesome photographer and drone operator based in Fernie, BC. Check out his work (and hire him!) by visiting his website at vmmedia.ca.

SPIRALING BEAUTY: AMMONITES AS INDEX FOSSILS

Argonauticeras besairei, Collection of José Juárez Ruiz.

An exceptional example of fractal building of an ammonite septum, in this clytoceratid Argonauticeras besairei from the awesome José Juárez Ruiz.

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells.

Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. 

They used these tentacles to snare prey, — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I'm sure you know. But the Ammonites were skilled and successful hunters. 

They caught their prey while swimming and floating in the water column. Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column.

They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. 

These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.

The Ammonoidea can be divided into six orders:

• Agoniatitida, Lower Devonian - Middle Devonian
• Clymeniida, Upper Devonian
• Goniatitida, Middle Devonian - Upper Permian
• Prolecanitida, Upper Devonian - Upper Triassic
• Ceratitida, Upper Permian - Upper Triassic
• Ammonitida, Lower Jurassic - Upper Cretaceous

Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from. 

If they are geometric with numerous undivided lobes and saddles and eight lobes around the conch, we refer to their pattern as goniatitic, a characteristic of Paleozoic ammonites.

If they are ceratitic with lobes that have subdivided tips; giving them a saw-toothed appearance and rounded undivided saddles, they are likely Triassic. For some lovely Triassic ammonites, take a look at the specimens that come out of Hallstatt, Austria and from the outcrops in the Humboldt Mountains of Nevada.

Hoplites bennettiana (Sowby, 1826).

If they have lobes and saddles that are fluted, with rounded subdivisions instead of saw-toothed, they are likely Jurassic or Cretaceous. 

If you'd like to see a particularly beautiful Lower Jurassic ammonite, take a peek at Apodoceras. Wonderful ridging in that species.

One of my favourite Cretaceous ammonites is the ammonite, Hoplites bennettiana (Sowby, 1826). This beauty is from Albian deposits near Carrière de Courcelles, Villemoyenne, near la région de Troyes (Aube) Champagne in northeastern France.

At the time that this fellow was swimming in our oceans, ankylosaurs were strolling about Mongolia and stomping through the foliage in Utah, Kansas and Texas. 

Bony fish were swimming over what would become the strata making up Canada, the Czech Republic and Australia. Cartilaginous fish were prowling the western interior seaway of North America and a strange extinct herbivorous mammal, Eobaatar, was snuffling through Mongolia, Spain and England.

In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida, and Ammonitida. Once you get to know them, ammonites in their various shapes and suturing patterns make it much easier to date an ammonite and the rock formation where is was found at a glance.

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago, and the last species vanished in the Cretaceous–Paleogene extinction event.

They were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. 

They were prolific back in the day, living (and sometimes dying) in schools in oceans around the globe. We find ammonite fossils (and plenty of them) in sedimentary rock from all over the world.

In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers rock to match up to specific geologic time periods, rather the way we use tree-rings to date trees. A handy way to compare fossils and date strata across the globe.

References: Inoue, S., Kondo, S. Suture pattern formation in ammonites and the unknown rear mantle structure. Sci Rep 6, 33689 (2016). https://doi.org/10.1038/srep33689
https://www.nature.com/articles/srep33689?fbclid=IwAR1BhBrDqhv8LDjqF60EXdfLR7wPE4zDivwGORTUEgCd2GghD5W7KOfg6Co#citeas

Photo: Hoplites Bennettiana from near Troyes, France. Collection de Christophe Marot

BACK IN THE USSR: KEPPLERITES

This glorious chocolate block contains the creamy grey ammonite Kepplerites gowerianus (Sowerby 1827) with a few invertebrate friends, including two brachiopods: Ivanoviella sp., Zeilleria sp. and the deep brown gastropod Bathrotomaria sp. 

There is also a wee bit of petrified wood on the backside.

These beauties hail from Jurassic, Lower Callovian outcrops in the Quarry of Kursk Magnetic Anomaly (51.25361,37.66944), Kursk region, Russia. Diameter ammonite 70мм. 

In the mid-1980s, during the expansion and development of one of the quarries, an unusual geological formation was found. This area had been part of the seafloor around an ancient island surrounded by Jurassic Seas. 

The outcrops of this geological formation turned out to be very rich in marine fossil fauna. This ammonite block was found there years ago by the deeply awesome Emil Black. 

In more recent years, the site has been closed to fossil collecting and is in use solely for the processing and extraction of iron ore deposits. Kursk Oblast is one of Russia's major producers of iron ore. The area of the Kursk Magnetic Anomaly has one of the richest iron-ore deposits in the world. Rare Earth minerals and base metals also occur in commercial quantities in several locations. Refractory loam, mineral sands, and chalk are quarried and processed in the region. 

The Kursk Magnetic Anomaly Quarry is not far from the Sekmenevsk Formation or Sekmenevska Svita in Russian, a Cretaceous (Albian to Cenomanian) terrestrial geologic formation where Pterosaur fossils have been found in the sandstones. 

OIL IN WATER BEAUTY: FOSSILS OF FOLKSTONE

Sheer beauty — a beautiful Euhoplites ammonite from Folkstone, UK. I've been really enjoying looking at all oil-in-water colouring and chunkiness of these ammonites.

Euhoplites is an extinct ammonoid cephalopod from the Lower Cretaceous, characterized by strongly ribbed, more or less evolute, compressed to inflated shells with flat or concave ribs, typically with a deep narrow groove running down the middle.

In some, ribs seem to zigzag between umbilical tubercles and parallel ventrolateral clavi. In others, the ribs are flexious and curve forward from the umbilical shoulder and lap onto either side of the venter.

Its shell is covered in the lovely lumps and bumps we associate with the genus. The function of these adornments are unknown. I wonder if they gave them greater strength to go deeper into the ocean to hunt for food. 

They look to have been a source of hydrodynamic drag, likely preventing Euhoplites from swimming at speed. Studying them may give some insight into the lifestyle of this ancient marine predator. Euhoplites had shells ranging in size up to a 5-6cm. 

We find them in Lower Cretaceous, middle to upper Albian age strata. Euhoplites has been found in Middle and Upper Albian beds in France where it is associated respectively with Hoplites and Anahoplites, and Pleurohoplites, Puzosia, and Desmoceras; in the Middle Albian of Brazil with Anahoplites and Turrilites; and in the Cenomanian of Texas.

This species is the most common ammonite from the Folkstone Fossil Beds in southeastern England where a variety of species are found, including this 37mm beauty from the collections of José Juárez Ruiz.

QUENSTEDTOCERAS WITH PATHOLOGY

What you are seeing here is a protuberance extruding from the venter of Quenstedtoceras cf. leachi (Sowerby). It is a pathology in the shell from hosting immature bivalves that shared the seas with these Middle Jurassic, Upper Callovian, Lamberti zone fauna from the Volga River basin. 

The collecting site is the now inactive Dubki commercial clay quarry and brickyard near Saratov, Russia. 

The site has produced thousands of ammonite specimens. A good 1,100 of those ended up at the Black Hills Institute of Geological Research in Hill City, South Dakota. 

Roughly 1,000 of those are Quenstedtoceras (Lamberticeras) lamberti and the other 100 are a mix of other species found in the same zone. These included Eboraciceras, Peltoceras, Kosmoceras, Grossouvria, Proriceras, Cadoceras and Rursiceras. 

What is especially interesting is the volume of specimens — 167 Quenstedtoceras (Lamberticeras) lamberti and 89 other species in the Black Hills collection — with healed predation injuries. It seems Quenstedtoceras (Lamberticeras) lamberti are the most common specimens found here and so not surprisingly the most common species found injured. 

Of the 1,000, 655 of the Quenstedtoceras (Lamberticeras) lamberti displayed some sort of deformation or growth on the shell or had grown in a tilted manner. 

Again, some of the Q. lamberti had small depressions in the centre likely due to a healed bite and hosting infestations of the immature bivalve Placunopsis and some Ostrea. 

The bivalves thrived on their accommodating hosts and the ammonites carried on, growing their shells right up and over their bivalve guests. 

This relationship led to some weird and deformities of their shells. They grow in, around, up and over nearly every surface of the shell and seem to have lived out their lives there. It must have gotten a bit unworkable for the ammonites, their shells becoming warped and unevenly weighted. 

Over time, both the flourishing bivalves and the ammonite shells growing up and over them produced some of the most interesting pathology specimens I have ever seen.    

In the photo here from Emil Black, you can see some of the distorted shapes of Quenstedtoceras sp. 

Look closely and you see a trochospiral or flattened appearance on one side while they are rounded on the other. 

All of these beauties hail from the Dubki Quarry near Saratov, Russia. The ammonites were collected in marl or clay used in brick making. The clay particles suggest a calm, deep marine environment. 

One of the lovely features of the preservation here is the amount of pyrite filling and replacement. It looks like these ammonites were buried in an oxygen-deficient environment. 

The ammonites were likely living higher in the water column, well above the oxygen-poor bottom. An isotopic study would be interesting to prove this hypothesis. 

There's certainly enough of these ammonites that have been recovered to make that possible. It's estimated that over a thousand specimens have been recovered from the site but that number is likely much higher. But these are not complete specimens. We mostly find the phragmocones and partial body chambers. Given the numbers, this may be a site documenting a mass spawning death over several years or generations.

If you fancy a read on all things cephie, consider picking up a copy of Cephalopods Present and Past: New Insights and Fresh Perspectives edited by Neil Landman and Richard Davis. Figure 16.2 is from page 348 of that publication and shows the hosting predation quite well. 

Photos: Courtesy of the deeply awesome Emil Black. These are in his personal collection that I hope to see in person one day. 

It was his sharing of the top photo and the strange anomaly that had me explore more about the fossils from Dubki and the weird and wonderful hosting relationship between ammonites and bivalves. Thank you, my friend!

BACK IN THE USSR: BEADANTICERAS OF THE NORTHERN CAUCASUS

This lovely oil in water coloured ammonite is the beauty Beudanticeras sp. from the Lower Cretaceous (Upper Aptian), Krasnodar region, Northern Caucasus, southern Russia. 

This area of the world has beautiful fossil specimens with their distinct colouring. The geology and paleontological history of the region are fascinating as is its more recent history. 

The territory of present Krasnodar Krai was inhabited as early as the Paleolithic, about 2 million years ago. It was inhabited by various tribes and peoples since ancient times. 

There were several Greek colonies on the Black Sea coast, which later became part of the Kingdom of the Bosporus. In 631, the Great Bulgaria state was founded in the Kuban. In the 8th-10th centuries, the territory was part of Khazaria.

In 965, the Kievan Prince Svyatoslav defeated the Khazar Khanate and this region came under the power of Kievan Rus, Tmutarakan principality was formed. At the end of the 11th century, in connection with the strengthening of the Polovtsy and claims of Byzantium, Tmutarakan principality came under the authority of the Byzantine emperors (until 1204).

In 1243-1438, this land was part of the Golden Horde. After its collapse, Kuban was divided between the Crimean Khanate, Circassia, and the Ottoman Empire, which dominated in the region. Russia began to challenge the protectorate over the territory during the Russian-Turkish wars.

In 1783, by decree of Catherine II, the right-bank Kuban and Taman Peninsula became part of the Russian Empire after the liquidation of the Crimean Khanate. 

In 1792-1793, Zaporozhye (Black Sea) Cossacks resettled here to protect new borders of the country along the Kuban River. 

During the military campaign to establish control over the North Caucasus (Caucasian War of 1763-1864), in the 1830s, the Ottoman Empire for forced out of the region and Russia gained access to the Black Sea coast.

Prior to the revolutionary events of 1917, most of the territory of present Krasnodar Krai was occupied by the Kuban region, founded in 1860. In 1900, the population of the region was about 2 million people. In 1913, it ranked 2nd by the gross harvest of grain, 1st place for the production of bread in the Russian Empire.

The Kuban was one of the centres of resistance after the Bolshevik revolution of 1917. In 1918-1920, there was a non-Bolshevik Kuban People’s Republic. In 1924, North-Caucasian krai was founded with the centre in Rostov-on-Don. In 1934, it was divided into Azov-Black Sea krai (Rostov-on-Don) and North Caucasus krai (Stavropol).

September 13, 1937, the Azov-Black Sea region was divided into the Rostov region and Krasnodar Krai that included Adygei autonomous oblast. During the Second World War, the region was captured by the Germans. After the battle for the Caucasus, it was liberated. There are about 1,500 monuments and memorials commemorating heroes of the war on the territory of Krasnodar Krai.

The lovely block you see here is in the collections of the awesome John Fam, Vice-Chair of the Vancouver Paleontological Society in British Columbia, Canada.

FRACTAL BUILDING: AMMONITES

Argonauticeras besairei, Collection of José Juárez Ruiz.

An exceptional example of fractal building of an ammonite septum, in this clytoceratid Argonauticeras besairei from the awesome José Juárez Ruiz.

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells.

Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey, — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I'm sure you know. But the Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column.

They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.

The Ammonoidea can be divided into six orders:

• Agoniatitida, Lower Devonian - Middle Devonian
• Clymeniida, Upper Devonian
• Goniatitida, Middle Devonian - Upper Permian
• Prolecanitida, Upper Devonian - Upper Triassic
• Ceratitida, Upper Permian - Upper Triassic
• Ammonitida, Lower Jurassic - Upper Cretaceous

Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from. If they are geometric with numerous undivided lobes and saddles and eight lobes around the conch, we refer to their pattern as goniatitic, a characteristic of Paleozoic ammonites.

If they are ceratitic with lobes that have subdivided tips; giving them a saw-toothed appearance and rounded undivided saddles, they are likely Triassic. For some lovely Triassic ammonites, take a look at the specimens that come out of Hallstatt, Austria and from the outcrops in the Humboldt Mountains of Nevada.

Hoplites bennettiana (Sowby, 1826).

If they have lobes and saddles that are fluted, with rounded subdivisions instead of saw-toothed, they are likely Jurassic or Cretaceous. If you'd like to see a particularly beautiful Lower Jurassic ammonite, take a peek at Apodoceras. Wonderful ridging in that species.

One of my favourite Cretaceous ammonites is the ammonite, Hoplites bennettiana (Sowby, 1826). This beauty is from Albian deposits near Carrière de Courcelles, Villemoyenne, near la région de Troyes (Aube) Champagne in northeastern France.

At the time that this fellow was swimming in our oceans, ankylosaurs were strolling about Mongolia and stomping through the foliage in Utah, Kansas and Texas. Bony fish were swimming over what would become the strata making up Canada, the Czech Republic and Australia. Cartilaginous fish were prowling the western interior seaway of North America and a strange extinct herbivorous mammal, Eobaatar, was snuffling through Mongolia, Spain and England.

In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida, and Ammonitida. Once you get to know them, ammonites in their various shapes and suturing patterns make it much easier to date an ammonite and the rock formation where is was found at a glance.

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago, and the last species vanished in the Cretaceous–Paleogene extinction event.

They were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. They were prolific back in the day, living (and sometimes dying) in schools in oceans around the globe. We find ammonite fossils (and plenty of them) in sedimentary rock from all over the world.

In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers rock to match up to specific geologic time periods, rather the way we use tree-rings to date trees. A handy way to compare fossils and date strata across the globe.

References: Inoue, S., Kondo, S. Suture pattern formation in ammonites and the unknown rear mantle structure. Sci Rep 6, 33689 (2016). https://doi.org/10.1038/srep33689
https://www.nature.com/articles/srep33689?fbclid=IwAR1BhBrDqhv8LDjqF60EXdfLR7wPE4zDivwGORTUEgCd2GghD5W7KOfg6Co#citeas

Photo: Hoplites Bennettiana from near Troyes, France. Collection de Christophe Marot

LOOPS, LURCHES AND LATE CRETACEOUS SEAS: MEET AUDOULICERAS

Audouliceras Heteromorph Ammonite

There are sensible ammonites… and then there are the heteromorphs.

Audouliceras belongs firmly in the second camp.

This wonderfully eccentric Cretaceous ammonite abandoned the classic tight spiral that most of its kin wore so elegantly and instead opted for something that looks, at first glance, like a shell having second thoughts. 

Its whorls uncoil, loop, and flare in ways that feel almost rebellious — as though the blueprint for “proper ammonite” was politely ignored.

Audouliceras lived during the Late Cretaceous, roughly 100–90 million years ago, when warm epicontinental seas flooded vast stretches of the globe. 

In North America, its fossils are found in marine sediments laid down by the Western Interior Seaway — that immense inland ocean that once split the continent in two. 

Beautiful specimens have turned up in Cretaceous deposits of Alberta, British Columbia, Montana, and the U.S. Great Plains, preserved in shales and sandstones that were once quiet seafloors.

Across the Atlantic realm, relatives occur in European Cretaceous deposits as well, reflecting the broad distribution of ammonites in the world’s warm, shallow seas. 

These were not shoreline creatures; Audouliceras drifted or swam in open marine environments, buoyed by gas-filled chambers within its shell. Like other ammonites, it controlled its position in the water column through a siphuncle — a delicate tube threading through its chambers, regulating buoyancy with remarkable precision.

What did it eat? Likely small crustaceans, plankton, and other tiny drifting life. Its soft body would have extended from the final chamber, equipped with tentacles and a beak-like mouth similar to that of modern squids and nautiluses. 

Heteromorph ammonites are often interpreted as slower, more vertical drifters compared to their tightly coiled cousins — perhaps hovering, bobbing, or gently pulsing through the water column rather than actively cruising.

And the seas they inhabited? Oh, they were anything but quiet.

Audouliceras shared its world with formidable predators and strange contemporaries. Giant marine reptiles patrolled the waters — long-necked plesiosaurs, sleek mosasaurs, and swift ichthyosaurs in earlier intervals. 

Sharks like Cretoxyrhina cruised the depths. Teleost fishes flashed through sunlit waters. Other ammonites — some tightly coiled, some extravagantly uncoiled — drifted alongside them, along with belemnites and rudist bivalves building reef-like structures on the seafloor.

In the fossil record, Audouliceras appears in Upper Cretaceous marine strata, often serving as a useful biostratigraphic marker. Ammonites evolved rapidly and had wide geographic ranges, making them excellent timekeepers for geologists. 

When you find Audouliceras in a rock layer, you are almost certainly standing in the Late Cretaceous.

Heteromorph ammonites like this one remind us that evolution is not a straight line toward efficiency or elegance. It experiments. It loops. It spirals outward and occasionally lets go of symmetry altogether.

And then — at the end of the Cretaceous, 66 million years ago — they vanished with the non-avian dinosaurs, casualties of the mass extinction that closed the chapter on the Mesozoic.

What remains are these curious, uncoiled shells in stone — records of a warm sea long gone, and of a lineage that was never afraid to look a little different.

COILED PERFECTION: LYTOCERAS

A superbly prepped and extremely rare Lytoceras (Suess, 1865) ammonite found as a green ammonite nodule by Matt Cape in the Lower Lias of Dorset. 

Lytoceras are rare in the Lower Lias of Dorset — apart from the Belemnite Stone horizon — so much so that Paul Davis, whose skilled prep work you see here, initially thought it might be a Becheiceras hidden within the large, lumpy nodule. 

One of the reasons these lovelies are rarely found from here is that they are a Mediterranean Tethyian genus. The fossil fauna we find in the United Kingdom are dominated by Boreal Tethyian genera. 

We do find Lytoceras sp. in the Luridum subzone of the Pliensbachian showing that there was an influx of species from the Mediterranean realm during this time. This is the first occurrence of a Lytoceras that he has ever seen in a green nodule and Paul's seen quite a few. 

This absolutely cracking specimen was found and is in the collections of the awesome Matt Cape. Matt recognized that whatever was hidden in the nodule would take skilled and careful preparation using air scribes. Indeed it did. It took more than five hours of time and skill to unveil the lovely museum-worthy specimen you see here. 

We find Lytoceras in more than 1,000 outcrops around the globe ranging from the Jurassic through to the Cretaceous, some 189.6 to 109.00 million years ago. Once this specimen is fully prepped with the nodule material cut or scraped away, you can see the detailed crinkly growth lines or riblets on the shell and none of the expected coarse ribbing. 

Lytoceras sp. Photo: Craig Chivers

If you imagine running your finger along these, you would be tracing the work of decades of growth of these cephalopods. 

While we cannot know their actual lifespans, but we can make a healthy guess. 

The nautilus, their closest living cousins live upwards of 20 years — gods be good — and less than three years if conditions are poor.

The flanges, projecting flat ribs or collars, develop at the edge of the mouth border on the animal's mantle as they grow each new chamber. 

Each delicate flange grows over the course of the ammonites life, marking various points in time and life stages as the ammonite grew. There is a large variation within Lytoceras with regards to flanges. They provide both ornamentation and strength to the shell to protect it from water pressure as they moved into deeper seas.

The concretion prior to prep

This distinctive genus with its evolute shells are found in the Cretaceous marine deposits of: 

Antarctica (5 collections), Austria (19), Colombia (1), the Czech Republic (3), Egypt (2), France (194), Greenland (16), Hungary (25), Italy (11), Madagascar (2), Mexico (1), Morocco (4), Mozambique (1), Poland (2), Portugal (1), Romania (1), the Russian Federation (2), Slovakia (3), South Africa (1), Spain (24), Tanzania (1), Trinidad and Tobago (1), Tunisia (25); and the United States of America (17: Alaska, California, North Carolina, Oregon).

We also find them in Jurassic marine outcrops in:

Austria (15), Canada (9: British Columbia), Chile (6), France (181), Germany (11), Greenland (1), Hungary (189), India (1), Indonesia (1), Iran (1), Italy (50), Japan (14), Kenya (2), Luxembourg (4), Madagascar (2), Mexico (1), Morocco (43), New Zealand (15), Portugal (1), Romania (5), the Russian Federation (1), Slovakia (1), Spain (6), Switzerland (2), Tunisia (11), Turkey (12), Turkmenistan (1), Ukraine (5), the United Kingdom (12), United States (11: Alaska, California) — in at least 977 known collections. 

References:

Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Cephalopoda entry)". Bulletins of American Paleontology. 363: 1–560. Archived from the original on 2008-05-07. Retrieved 2017-10-18.

Paleobiology Database - Lytoceras. 2017-10-19.

Systematic descriptions, Mesozoic Ammonoidea, by W.J Arkell, Bernhard Kummel, and C.W. Wright. 1957. Treatise on Invertebrate Paleontology, Part L. Geological Society of America and University of Kansas press.

A MASSIVE AMMONITE THE SIZE OF A CAR: THE FERNIE AMMONITE

Titanites occidentalis, Fernie Ammonite

The Fernie ammonite—long known as Titanites occidentalis—has officially been given a new name: Corbinites occidentalis, a fresh genus erected after a meticulous re-evaluation of this Western Giant’s anatomy and lineage. 

What hasn’t changed is its breathtaking presence high on Coal Mountain near Fernie, British Columbia, where this colossal cephalopod has rested for roughly 150 million years.

This extraordinary fossil belongs to the family Lithacoceratinae within the ataxioceratid ammonites. 

Once thought to be a close cousin of the great Titanites of Dorset, new material—including two additional large specimens discovered at nearby mine sites—reveals ribbing patterns and growth-stage features that simply didn’t match Titanites. 

With these multiple overlapping growth stages finally available, paleontologists had the missing pieces needed to correct its identity.

So, Titanites occidentalis no more—meet Corbinites occidentalis, a giant ammonite likely endemic to the relatively isolated early Alberta foreland basin of the Late Jurassic.

Fernie, British Columbia, Canada

The Fernie ammonite is a carnivorous cephalopod from the latest Jurassic (Tithonian). 

The spectacular individual on Coal Mountain measures 1.4 metres across—about the size of a small car tire and absolutely staggering when you first see it hugged by the mountainside.

The first specimen, discovered in 1947 by a British Columbia Geophysical Society mapping team at Coal Creek, was initially mistaken for a “fossil truck tire.” 

Fair enough—if a truck tire had been forged in the Jurassic and left on a mountaintop. It was later described by GSC paleontologist Hans Frebold, who gave it the name Titanites occidentalis, inspired by the giant ammonites of Dorset. 

For decades, that name stuck, even though paleontologists suspected the attribution was shaky due to poor preservation of the holotype’s inner whorls.

Recent discoveries of two additional specimens at Teck Resources’ Coal Mountain Mine finally provided the evidence needed for reassessment. 

With intact inner whorls and beautifully preserved ribbing—including hallmark variocostate and ataxioceratoid ornamentation—researchers Terence P. Poulton and colleagues demonstrated that the Canadian ammonite does not belong in Titanites. 

Their work (Volumina Jurassica, 2023) established Corbinites as a brand-new genus, with C. occidentalis as its type and only known species.

These specimens—one exceeding a metre, another about 64 cm—confirm a resident ammonite population within this basin. And as of now, these giants are unique to Western Canada.

A Journey Up Coal Mountain

If you’re keen to meet Corbinites occidentalis in the wild, you’ll want to head to Fernie, in southeastern British Columbia, close to the Alberta border. 

As your feet move up the hillside, you can imagine this land 10,000 years ago, rising above great glaciers. Where footfalls trace the steps of those that came before you. This land has been home to the Yaq̓it ʔa·knuqⱡi ‘it First Nation and Ktunaxa or Kukin ʔamakis First Nations whose oral history have them living here since time immemorial. Like them, take only what you need and no more than the land offers — packing out anything that you packed in. 

Active logging in the area since 2021 means that older directions are now unreliable—trailheads have shifted, and a fair bit of bushwhacking is the price of admission. Though clear-cutting reshaped the slope, loggers at CanWel showed admirable restraint: they worked around the fossil, leaving it untouched.

The non-profit Wildsight has been championing efforts to protect the ammonite, hoping to establish an educational trail with provincial support and possible inclusion under the Heritage Conservation Act—where the fossil’s stewardship could be formally recognised.

HIKING TO THE FERNIE AMMONITE (IMPORTANT UPDATE: TRAIL CLOSED)

From the town of Fernie, British Columbia, you would traditionally head east along Coal Creek Road toward Coal Creek, with the ammonite site sitting 3.81 km from the road’s base as the crow flies. 

The classic approach begins at a roadside exposure of dark grey to black Cretaceous plant fossils, followed by a creek crossing and a steep, bushwhacking ascent.

However — and this is critical — the trail is currently closed.

The entire access route runs straight through an area of active logging, and conditions on the slope are extremely dangerous. Between heavy equipment, unstable cutblocks, and altered drainages, this is not a safe place for hikers right now.

Conservation groups, including Wildsight, continue working toward restoring safe public access and formalising the site under the Heritage Conservation Act. 

Their long-term goal is to reopen the trail as a designated educational hike with proper signage, but at present, the route should not be attempted. 

Once logging operations move out of the area and safety assessments are done, the possibility of reopening may return.

For now, the safest—and strongly recommended—way to view this iconic fossil is via the excellent cast on display at the Courtenay & District Museum on Vancouver Island, or at the Visitor Information Centre in Sparwood.

Photo credit: Vince Mo Media. Vince is an awesome photographer and drone operator based in Fernie, BC. Check out his work (and hire him!) by visiting his website at vmmedia.ca.

AMMONITES IN CONCRETION

At first glance they look like ordinary stones—rounded, weathered, unassuming. 

But then you notice the delicious hints: a spiral ghosting through the surface, a faint rib, a seam where time is ready to split wide open—it's magic!

Ammonites, long extinct cephalopods, so often appear this way because, shortly after death, their shells became chemical centres of attraction on the seafloor. 

As the soft tissues decayed, they altered the surrounding sediment, triggering minerals—often calcium carbonate or iron-rich compounds—to precipitate rapidly around the shell. 

This early cementation formed a concretion, a protective stone cocoon that hardened long before the surrounding mud was compressed into rock. While everything around it flattened, cracked, and distorted under pressure, the ammonite inside remained cradled and whole.

What you see here is a gathering of these time capsules: a cluster of ammonites preserved in their concretions, each one split or weathered just enough to reveal the coiled story within. 

Some are neatly halved, spirals laid bare like fingerprints from ages past; others are only just beginning to show themselves, teasing their presence beneath rough stone skins. 

Together, they tell a familiar fossil-hunter’s tale—of patience, sharp eyes, and the thrill of knowing that this unassuming rock holds an ancient ocean inside.

TASEKO LAKES FOSSIL ADVENTURE

John Fam, VIPS & VanPS

Over three field seasons, thirty-five taxa from the Mineralense and Rursicostatum zones were studied and three new species were discovered and named: Fergusonites hendersonae, Eolytoceras constrictum and Pseudaetomoceras victoriense. 

The late Hettangian ammonite fauna from Taseko Lakes is diverse and relatively well‐preserved.

This material is very important as it greatly expands our understanding of the fauna and ranges of ammonites currently included in the North American regional ammonite zonation. 

Castle Peak, Taseko Lakes

If you look closely, you can see a wee jet ranger helicopter hovering over a very chilly Castle Peak in the southern Chilcotin Range, British Columbia, Canada. 

Castle Peak served as our glorious landmark and loadstone of basalt that marked the spot on our Jurassic/Triassic palaeo adventures collecting about 7000 ft. 

The peak itself reaches higher still to around 8,176 ft. 

The site is special, both in terms of its geology and paleontological bounty, but also for the time spent there with friends. 

I had the very great honour of having the newly named, Fergusonites hendersonae, a new species of nektonic carnivorous ammonite, named after me by palaeontologist Louse Longridge from the University of British Columbia. 

Fergusonites hendersonae (Longridge, 2008)

I had met Louise as an undergrad and was pleased as punch to hear that she would be continuing the research by Dr. Howard Tipper, the authority on this area of the Chilcotins and Haida Gwaii — which he dearly loved. 

"Tip" was a renowned Jurassic ammonite palaeontologist and an excellent regional mapper who mapped large areas of the Cordillera. 

He made significant contributions to Jurassic paleobiogeography and taxonomy in collaboration with Dr. Paul Smith, Head of Earth and Ocean Science at the University of British Columbia. 

Tip’s regional mapping within BC has withstood the test of time and for many areas became the region's base maps for future studies. The scope of Tip’s understanding of Cordilleran geology and Jurassic palaeontology will likely never be matched. He passed away on April 21, 2005. His humour, knowledge and leadership will be sorely missed. 

Badouxia ammonites

Before he left us, he shared that knowledge with many of whom would help to secure his legacy for future generations. 

We did several trips over the years up to the Taseko Lake area of the Rockies joined by many wonderful researchers from the Vancouver Island Palaeontological Society and Vancouver Paleontological Society, as well as the University of British Columbia. 

Both Dan Bowen and John Fam were instrumental in planning those expeditions and each of them benefited greatly from the knowledge of Dr. Howard Tipper. 

If not for Tipper's early work in the region, our shared understanding and much of what was accomplished in his last years and after his passing would not have been possible. 

Over the course of three field seasons, we endured elevation sickness, rain, snow, grizzly bears and very chilly nights  — we were sleeping right next to a glacier at one point — but were rewarded by the enthusiastic crew, and helicopter rides — which really cut down the hiking time — excellent specimens including three new species of ammonites, along with a high-spired gastropod and lobster claw that have yet to be written up. 

This area of the world is wonderful to hike and explore — a stunningly beautiful country. We were also blessed with access as the area is closed to all fossil collecting except with a permit.

HOLCOPHYLLOCERAS: A JEWEL OF JURASSIC SEAS

What is most wonderful about natural science is that every fossil—every spiral, ridge, and suture—opens a window onto a vanished world. 

Take, for instance, this tremendously robust, intricately sutured ammonite: Holcophylloceras mediterraneum (Neumayr, 1871). Collected from Late Jurassic (Oxfordian) deposits near Sokoja, Madagascar, it is a marvel of paleontological sculpture, a testament to evolutionary experimentation that thrived in the tropical Tethyan seas some 160 million years ago.

Madagascar has long been recognized as a treasure trove of beautifully preserved fossils. From its Cretaceous dinosaurs to its Triassic amphibians and its extraordinary Jurassic ammonites, the island offers a richness few regions can rival. 

The spiraled shell of Holcophylloceras mediterraneum is no exception—its ornate sutures and lustrous preservation hint at a creature exquisitely adapted to the warm, shallow continental shelf of Gondwana’s eastern margin.

Like all ammonites, Holcophylloceras built its shell in a series of chambers divided by walls known as septa. These septa, when intersecting the outer shell, formed the elaborate suture patterns that make collectors swoon—tangled, fractal-like lines that resemble botanical tracings or rivers on an ancient map.

Running through each chamber was the siphuncle, a biological marvel that allowed the ammonite to adjust the gas and fluid content inside its shell. In effect, ammonites carried a set of built-in ballast tanks, enabling them to rise and sink through the water column almost effortlessly. Their final and largest chamber—the body chamber—housed the soft tissues, including the tentacles, eyes, and muscular arms.

Picture, if you will, a squid or octopus, then surround it with a coiled, beautifully ribbed shell. Now place it in a warm tropical sea filled with predators and prey, reefs and drifting plankton, and a ton upon ton of water pressing down from above. That was the world Holcophylloceras mastered.

The Oxfordian oceans surrounding Madagascar were not quiet waters. They were alive—thrumming with movement, colour, and competition. The ammonite’s elegant spiral belies the reality of its bustling neighbourhood. Some of the many animals that would have swum, crawled, hunted, or drifted around Holcophylloceras mediterraneum include:

Marine Reptiles

• Plesiosaurs – long-necked Cryptoclidus–like forms gliding between shoals of fish.
• Ichthyosaurs – such as Ophthalmosaurus, sleek torpedo-shaped hunters with dinner-plate eyes built for dim, deeper waters.
• Pliosaurs – apex predators like Liopleurodon, whose cavernous jaws could swallow a human whole.

Other Cephalopods

Belemnites – dart-shaped squid-relatives such as Hibolithes, flickering through the water column like living arrows.

Other ammonite genera sharing these seas:

• Perisphinctes
• Asaphoceras
• Physodoceras
• Aspidoceras
• Glochiceras

Each species filled its own ecological niche, from fast-swimming pursuit hunters to slow-drifting plankton feeders.

Fishes and Sharks

• Hybodont sharks – including Hybodus and Asteracanthus, equipped with crushing teeth for shelled prey and formidable dorsal spines.
• Teleost fishes – early ray-finned fishes beginning to diversify.
• Coelacanths – ancient lobe-finned holdovers patrolling calmer waters.

Invertebrates

• Bivalves – oysters, rudists, and inoceramids carpeting the shallow seafloor.
• Gastropods – from turreted turritellids to broad-shelled neritids.
• Crustaceans – shrimp, lobsters, and small crabs scraping algae from reef structures.
• Sea urchins and echinoids – spiny architects of sandy burrows.

Reefs & Drifting Life

• Sponges and corals creating pocket reefs in warm carbonate-rich environments.
• Planktonic foraminifera and radiolarians – the drifting micro-architecture of the Jurassic sea, powering food webs from below.

Ammonites like Holcophylloceras thrived in these diverse ecosystems by filling a mid-level trophic niche. They were both predator and prey—nimble enough to hunt small fish and crustaceans, yet vulnerable to larger hunters. Their greatest evolutionary advantage was their ability to regulate buoyancy, adjusting depth as easily as a modern submarine.

But their most beautiful legacy remains their shells. In death, they fell to the seafloor, where their chambers filled with sediment, minerals, and eventually time itself. 

Today, polished by erosion or revealed in limestone, they offer a perfect blend of geometry, biology, and ancient artistry.

LOWER LIAS LYTOCERAS AMMONITE

A superbly prepped and extremely rare Lytoceras (Suess, 1865) ammonite found as a green ammonite nodule by Matt Cape in the Lower Lias of Dorset. 

Lytoceras are rare in the Lower Lias of Dorset — apart from the Belemnite Stone horizon — so much so that Paul Davis, whose skilled prep work you see here, initially thought it might be a Becheiceras hidden within the large, lumpy nodule. 

One of the reasons these lovelies are rarely found from here is that they are a Mediterranean Tethyian genus. The fossil fauna we find in the United Kingdom are dominated by Boreal Tethyian genera. 

We do find Lytoceras sp. in the Luridum subzone of the Pliensbachian showing that there was an influx of species from the Mediterranean realm during this time. This is the first occurrence of a Lytoceras that he has ever seen in a green nodule and Paul's seen quite a few. 

This absolutely cracking specimen was found and is in the collections of the awesome Matt Cape. Matt recognized that whatever was hidden in the nodule would take skilled and careful preparation using air scribes. Indeed it did. It took more than five hours of time and skill to unveil the lovely museum-worthy specimen you see here. 

We find Lytoceras in more than 1,000 outcrops around the globe ranging from the Jurassic through to the Cretaceous, some 189.6 to 109.00 million years ago. Once this specimen is fully prepped with the nodule material cut or scraped away, you can see the detailed crinkly growth lines or riblets on the shell and none of the expected coarse ribbing. 

Lytoceras sp. Photo: Craig Chivers

If you imagine running your finger along these, you would be tracing the work of decades of growth of these cephalopods. 

While we cannot know their actual lifespans, but we can make a healthy guess. 

The nautilus, their closest living cousins live upwards of 20 years — gods be good — and less than three years if conditions are poor.

The flanges, projecting flat ribs or collars, develop at the edge of the mouth border on the animal's mantle as they grow each new chamber. 

Each delicate flange grows over the course of the ammonites life, marking various points in time and life stages as the ammonite grew. There is a large variation within Lytoceras with regards to flanges. They provide both ornamentation and strength to the shell to protect it from water pressure as they moved into deeper seas.

The concretion prior to prep

This distinctive genus with its evolute shells are found in the Cretaceous marine deposits of: 

Antarctica (5 collections), Austria (19), Colombia (1), the Czech Republic (3), Egypt (2), France (194), Greenland (16), Hungary (25), Italy (11), Madagascar (2), Mexico (1), Morocco (4), Mozambique (1), Poland (2), Portugal (1), Romania (1), the Russian Federation (2), Slovakia (3), South Africa (1), Spain (24), Tanzania (1), Trinidad and Tobago (1), Tunisia (25); and the United States of America (17: Alaska, California, North Carolina, Oregon).

We also find them in Jurassic marine outcrops in:

Austria (15), Canada (9: British Columbia), Chile (6), France (181), Germany (11), Greenland (1), Hungary (189), India (1), Indonesia (1), Iran (1), Italy (50), Japan (14), Kenya (2), Luxembourg (4), Madagascar (2), Mexico (1), Morocco (43), New Zealand (15), Portugal (1), Romania (5), the Russian Federation (1), Slovakia (1), Spain (6), Switzerland (2), Tunisia (11), Turkey (12), Turkmenistan (1), Ukraine (5), the United Kingdom (12), United States (11: Alaska, California) — in at least 977 known collections. 

References:

Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Cephalopoda entry)". Bulletins of American Paleontology. 363: 1–560. Archived from the original on 2008-05-07. Retrieved 2017-10-18.

Paleobiology Database - Lytoceras. 2017-10-19.

Systematic descriptions, Mesozoic Ammonoidea, by W.J Arkell, Bernhard Kummel, and C.W. Wright. 1957. Treatise on Invertebrate Paleontology, Part L. Geological Society of America and University of Kansas press.

INDEX FOSSILS: AMMONITES

Argonauticeras besairei, Collection of José Juárez Ruiz.

An exceptional example of fractal building of an ammonite septum, in this clytoceratid Argonauticeras besairei from the awesome José Juárez Ruiz.

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells.

Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey, — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I'm sure you know. But the Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column.

They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.

The Ammonoidea can be divided into six orders:

• Agoniatitida, Lower Devonian - Middle Devonian
• Clymeniida, Upper Devonian
• Goniatitida, Middle Devonian - Upper Permian
• Prolecanitida, Upper Devonian - Upper Triassic
• Ceratitida, Upper Permian - Upper Triassic
• Ammonitida, Lower Jurassic - Upper Cretaceous

Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from. If they are geometric with numerous undivided lobes and saddles and eight lobes around the conch, we refer to their pattern as goniatitic, a characteristic of Paleozoic ammonites.

If they are ceratitic with lobes that have subdivided tips; giving them a saw-toothed appearance and rounded undivided saddles, they are likely Triassic. For some lovely Triassic ammonites, take a look at the specimens that come out of Hallstatt, Austria and from the outcrops in the Humboldt Mountains of Nevada.

Hoplites bennettiana (Sowby, 1826).

If they have lobes and saddles that are fluted, with rounded subdivisions instead of saw-toothed, they are likely Jurassic or Cretaceous. If you'd like to see a particularly beautiful Lower Jurassic ammonite, take a peek at Apodoceras. Wonderful ridging in that species.

One of my favourite Cretaceous ammonites is the ammonite, Hoplites bennettiana (Sowby, 1826). This beauty is from Albian deposits near Carrière de Courcelles, Villemoyenne, near la région de Troyes (Aube) Champagne in northeastern France.

At the time that this fellow was swimming in our oceans, ankylosaurs were strolling about Mongolia and stomping through the foliage in Utah, Kansas and Texas. Bony fish were swimming over what would become the strata making up Canada, the Czech Republic and Australia. Cartilaginous fish were prowling the western interior seaway of North America and a strange extinct herbivorous mammal, Eobaatar, was snuffling through Mongolia, Spain and England.

In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida, and Ammonitida. Once you get to know them, ammonites in their various shapes and suturing patterns make it much easier to date an ammonite and the rock formation where is was found at a glance.

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago, and the last species vanished in the Cretaceous–Paleogene extinction event.

They were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. They were prolific back in the day, living (and sometimes dying) in schools in oceans around the globe. We find ammonite fossils (and plenty of them) in sedimentary rock from all over the world.

In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers rock to match up to specific geologic time periods, rather the way we use tree-rings to date trees. A handy way to compare fossils and date strata across the globe.

References: Inoue, S., Kondo, S. Suture pattern formation in ammonites and the unknown rear mantle structure. Sci Rep 6, 33689 (2016). https://doi.org/10.1038/srep33689
https://www.nature.com/articles/srep33689?fbclid=IwAR1BhBrDqhv8LDjqF60EXdfLR7wPE4zDivwGORTUEgCd2GghD5W7KOfg6Co#citeas

Photo: Hoplites Bennettiana from near Troyes, France. Collection de Christophe Marot

AINOCERAS OF VANCOUVER ISLAND

A wee baby deep chocolate Ainoceras sp. heteromorph ammonite from Vancouver Island. This adorable corkscrew-shaped ammonite is an extinct marine mollusc related to squid and octopus.  

Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. 

By pushing air in or out, they were able to control their buoyancy in the water column. These little cuties were predators who hunted in Cretaceous seas.

They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber. 

Not all ammonites have this whacky corkscrew design. Most are coiled and some are even shaped like massive paperclips. This one is so remarkable, so joyously perfect my internal thesaurus can’t keep up.

I will be heading back to the area where these lovelies are found in late March this year to see if I can find other associated fossils and learn more about his paleo community