# Fossilized Snail

A fossilized snail is the shell of a snail that lived long ago, or a stone copy of it. Fossil snails come from ancient seas, lakes and land.

- **Category:** [Ancient](https://www.snappit.app/explore/categories/ancient)
- **Rarity:** Common
- **Danger:** 1/5 · Very low

![Fossilized Snail](https://commons.wikimedia.org/w/index.php?title=Special:Redirect/file/Wind_Cave_boxwork_fossilized_snail.JPG&width=800)

Photo: National Park Service, Public domain · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Wind_Cave_boxwork_fossilized_snail.JPG)

## Appearance

The Fossilized Snail is often found as a beautifully preserved spiral shell, varying in size from tiny coils to large, robust forms. It typically displays earthy tones like grey, brown, or black, sometimes with intricate patterns from its original shell imprinted onto the stone. Its stony texture clearly shows the ancient creature's shape.

## Taxonomy

- **Kingdom:** Animalia

## Fossil snail, up close

A fossilised snail is the preserved shell, or the stony mould of a shell, of a gastropod that lived long ago. Gastropod fossils run from the Cambrian, more than 500 million years ago, to the present day, and come from ancient seas, lakes and land. Depending on how it was buried, a fossil snail may keep its original shell, have it replaced by minerals such as calcite, silica or pyrite, or survive only as a mould.

Also called: Fossil snail, Fossil gastropod, Snail fossil.

Snail shells have been turning to stone since the Cambrian. Spin one, x-ray it, bury it, then test yourself.

### Special abilities

- **Mud Blanket** (≈99% of fossils found are from sea animals): Fossil process: quick burial. Mud, sand or silt settles over a dead snail’s shell and shields it, the first step to becoming a fossil. [6][3]
  - Once remains are buried, decay slows because there is little oxygen under the sediment.
  - Burial is easiest under water, which is why around 99% of the fossils we find come from sea animals.
  - Fossilisation is a rare event: it needs a special set of conditions.
  - Where fossils we find come from (All fossils found): ≈99% sea animals
- **Stone Copy** (1,000s–millions of years to turn to stone): Fossil process: petrification. X-ray the shell to see minerals from groundwater filling its tiny spaces and slowly replacing it. [3][6]
  - Mineral-rich water moves through the buried rock and leaves calcium carbonate or silica behind in the shell.
  - In the end the minerals can replace the original material completely: the shell is literally turned to stone.
  - This can take thousands or even millions of years.
- **Stone Core** (0% original shell left in a steinkern): Fossil process: internal mould. The shell dissolves, and only the hardened mud that filled it is left: a steinkern. [3][1][20]
  - Mud packed into the empty shell hardens into rock. When the shell itself dissolves, this stone core is all that remains.
  - If the hollow left behind is later filled by other minerals, it becomes a cast.
  - Shell minerals can dissolve after burial, which is why some fossil snails survive only as moulds. Under UV light, old colour only shows on shells that have not dissolved or recrystallised.
- **Fool’s Gold** (FeS₂ pyrite, an iron sulfide): Fossil process: pyritisation. In oxygen-poor mud, microbes help turn a shell into shiny, brassy pyrite. [12][21]
  - Microbes in the mud break down sulfate and make sulfide. This reacts with dissolved iron to form pyrite.
  - Pyrite is one of several minerals, with calcite, silica, phosphate and siderite, that can preserve fossils.
  - In the Middle Jurassic clays of the Vaches Noires cliffs in Normandy, snail and other shells are rarely pyritised, while pieces of wood there are.
- **Agate Heart** (46–51 Ma age of Wyoming’s ‘Turritella agate’): Fossil process: silicification. Silica fills and replaces shells, turning a lake bed full of snails into hard, glassy chert. [14][3][15]
  - Wyoming’s “Turritella agate” is packed with the extinct freshwater snail Elimia tenera, in chalcedony-rich rock from an old lake.
  - It formed in the Green River Formation, 46–51 million years ago.
  - Acid that dissolves limestone leaves silica behind, so scientists can free silicified shells from the rock this way.
- **Ghost Stripes** (25 of 46 Jurassic shell species showed hidden colour): Fossil clue: under ultraviolet light, some fossil shells glow and show colour patterns that are invisible in daylight. [20][22]
  - In 2015 scientists shone UV light on Late Jurassic snail and clam shells from Normandy. 25 of 46 species showed patterns, about 100 million years older than any fluorescent shell patterns found before.
  - Under UV, 28 species of fossil cone snails from the Dominican Republic, 6.6–4.8 million years old, showed patterns. Thirteen were new to science.
  - Comparing these patterns with living snails helps scientists work out which groups the fossils belong to.
  - Late Jurassic snail and clam shells under UV: Showed colour patterns 25 species; Species tested 46 species
- **Deep Time** (541 Ma the snail fossil record begins; still debated): Fossil clue: layers of rock pile up over millions of years, oldest at the bottom, so the layer a snail sits in tells you its age. [1][23][7][8][5][4]
  - Gastropod fossils start in the Cambrian, about 541 million years ago. Which of the earliest tiny shells were true snails is still debated.
  - Ammonites are the best guide fossils for dating marine rocks. For younger, non-marine deposits in Britain, amino acids in Bithynia snail trapdoors help put Ice Age layers in order.
  - Snails outlived the ammonites, which died out about 66 million years ago, and have been the most common molluscs since the Palaeogene.
- **Fossil Hunt** (185 million years of Earth history on the Jurassic Coast): Finding fossils: search loose shingle on the beach, never the cliff, check the tide and go with an adult. [19][16][17][18]
  - On the Charmouth and Lyme Regis coast, fossils wash out of the cliffs onto the beach. That is where to look.
  - Check the tide times and collect on a falling tide. Keep clear of cliffs and mudflows: cliff falls happen without warning.
  - Collecting codes ask you not to dig in the cliffs without permission, and to record important finds. Wear goggles if anyone uses a hammer.

### Body parts

- **Shell** (≈80% of living molluscs are gastropods) [1][2][3]
  - A snail’s shell is one coiled tube, built from calcium carbonate crystals (calcite and/or aragonite) mixed with organic molecules.
  - Gastropods are by far the biggest group of molluscs: more than 62,000 living species have been described.
  - Hard parts like shells last much longer than soft bodies, which is why snail shells make such common fossils.
- **Apex** [1]
  - The apex is the tip of the spire, where the shell began.
  - In especially well-preserved fossils, the tiny larval shell (the protoconch) can still sit at the tip.
  - Most snails that have ever lived coil to the right: hold the tip up and the opening is on the right.
- **Aperture** (>30 million yrs amino acids kept in snail ‘trapdoors’) [4][1][5]
  - The aperture is the shell’s opening. Many sea snails living on muddy floors had a tube (siphon) here to draw in clean water.
  - Some snails close the opening with a trapdoor, the operculum, which is sometimes fossilised in place.
  - The calcite trapdoors of the freshwater snail Bithynia hold original amino acids for over 30 million years, and scientists use them to date old river deposits.
- **Rock** (≈99% of fossils found are from sea animals) [3][6]
  - Fossil snails sit in sedimentary rock such as limestone, mudstone or chert: hardened mud, sand and shell.
  - Fossils form best where sediment can bury remains quickly, such as on the sea floor. Rocky mountaintops are poor places for fossils.
  - Nearly all fossils found, around 99%, come from sea animals such as shellfish.
- **Rock layers** [7][8]
  - In undisturbed layers, the bottom layer was laid down first and is the oldest.
  - The English surveyor William “Strata” Smith collected fossil shells and found that each layer held its own fossils, so he could recognise a layer wherever it appeared.
  - Today ammonites are the star guide fossils, because each species lasted only a short time.
- **Changing waters** [9][10][11]
  - The Purbeck rocks of Dorset swap between freshwater, brackish and sea layers.
  - Lake snails such as Viviparus mark the freshwater layers; a sea-urchin bed shows when the sea came back.
  - In the Early Cretaceous, Britain was warm, with lagoons, lakes and rivers.
- **Internal mould** [3]
  - Mud often fills the inside of an empty shell. If the shell later dissolves away, that hardened filling is left: an internal mould, or steinkern (German for “stone core”).
  - A shell can also leave a hollow mould in the rock, and if new minerals fill that hollow later, they make a cast.
  - Internal moulds show the shape of the spiral inside, but not the outer ribs and colours.
- **Replaced shell** [3][12][13]
  - Water carrying dissolved minerals seeps through buried shells, and calcium carbonate or silica can fill and replace them. This is called petrification.
  - Other minerals can do the job too, including pyrite (fool’s gold).
  - Some shells skip the change: 45-million-year-old Campanile giganteum shells still contain their original aragonite.
- **Crystals** (46–51 Ma age of Wyoming ‘Turritella agate’) [14][3][15]
  - Silica can fill or replace shells as chalcedony, a fine-grained quartz. In Wyoming, lake snails in chalcedony-rich rock are known as “Turritella agate”.
  - Silicified shells survive acid that dissolves the limestone around them, so scientists can free them with acid and scan them.
- **Find spot** (155 km of World Heritage fossil coast in Dorset and East Devon) [16][17][18][19]
  - On fossil coasts, the best place to look is the loose material on the beach, not the cliffs.
  - Always check the tide times first and stay clear of the cliffs. Cliff falls happen suddenly and without warning.
  - Scientifically important finds should be recorded, for example at the Charmouth Heritage Coast Centre.

### Stats

| Stat | Value | Notes |
|---|---|---|
| Fossil record starts | 541 Ma | Cambrian; which early shells were true snails is debated [1][4][23] |
| Living species | 62,000+ | described; estimates run from 40,000 to 150,000 [2] |
| Share of molluscs | ≈80% | of living mollusc species are gastropods [2] |
| Living range | 5 km deep to 6,000 m up | from the deep ocean floor to high mountains [4] |
| Fossils from the sea | ≈99% | of all fossils found are from marine animals [6] |
| Fastest fossil growth | 600 mm a year | Campanile giganteum, measured along the spiral; Two 30 cm rulers end to end, every year [13] |
| Eocene sea, Paris | >30 °C | spring and autumn sea temperatures 45 million years ago; winters ≈24 °C [24] |
| ‘Turritella agate’ | 46–51 Ma | Elimia tenera lake beds, Wyoming [14] |
| Hidden colours | 25 of 46 | Late Jurassic snail and clam species showing patterns under UV [20] |
| Jurassic Coast | 155 km | of coast with about 185 million years of Earth history [19] |

### Photos

- [High-spired snail in Devonian limestone, Ohio, USA](https://commons.wikimedia.org/wiki/File:Fossil_gastropod_in_limestone_(Columbus_Limestone%2C_Middle_Devonian%3B_Quarry_Trails_Park%2C_Columbus%2C_Ohio%2C_USA)_3.jpg) (photo: James St. John, CC BY 2.0)
- [Internal mould (steinkern) of a Devonian snail, Kelleys Island, Ohio](https://commons.wikimedia.org/wiki/File:Gastropod_internal_mold_(Columbus_Limestone%2C_Middle_Devonian%3B_abandoned_quarry%2C_Kelleys_Island%2C_Lake_Erie%2C_Ohio%2C_USA)_7_(48620313692).jpg) (photo: James St. John, CC BY 2.0)
- [“Turritella agate”, full of Elimia tenera lake snails, Wyoming](https://commons.wikimedia.org/wiki/File:%22Turritella_Agate%22_(chertified_fossiliferous_lacustrine_limestone)_(Laney_Member%2C_Green_River_Formation%2C_Middle_Eocene%3B_southern_Wyoming%2C_USA)_2_(27416504768).jpg) (photo: James St. John, CC BY 2.0)
- [Campanile giganteum, the longest known fossil snail, Paris Basin](https://commons.wikimedia.org/wiki/File:Campanile_giganteum_(Lamarck%2C_1804).jpg) (photo: Jessica Utrup (Yale Peabody Museum of Natural History), CC0)
- [Cretaceous snails replaced by chalcedony, a fine-grained quartz](https://commons.wikimedia.org/wiki/File:Chalcedonized_fossil_gastropods_(Cretaceous%3B_possibly_from_Dakhla%2C_southern_Morocco)_(15230327942).jpg) (photo: James St. John, CC BY 2.0)
- [Elimia tenera shells in lake chert, 5.7 cm across](https://commons.wikimedia.org/wiki/File:Elimia_tenera_fossil_gastropods_in_lacustrine_fossiliferous_chert_(%22Turritella_Agate%22%2C_Green_River_Formation%2C_Lower_Eocene%3B_southern_Wyoming%2C_USA)_(15043934260).jpg) (photo: James St. John, CC BY 2.0)
- [Ordovician snail fossils on Ontika beach, Estonia](https://commons.wikimedia.org/wiki/File:Ordovician_period_snail_fossils_from_Ontika_beach.jpg) (photo: ErikAbner, CC BY 4.0)
- [Another Devonian snail steinkern, Ohio](https://commons.wikimedia.org/wiki/File:Gastropod_internal_mold_(Columbus_Limestone%2C_Middle_Devonian%3B_abandoned_quarry%2C_Kelleys_Island%2C_Lake_Erie%2C_Ohio%2C_USA)_1_(48620312332).jpg) (photo: James St. John, CC BY 2.0)
- [Campanile giganteum, a giant Eocene sea snail](https://commons.wikimedia.org/wiki/File:Campanile_giganteum2.jpg) (photo: Peter Massicard, CC BY-SA 4.0)

### Questions

- **How old are fossil snails?** Gastropod fossils go back to the Cambrian, about 541 million years ago, and continue to the present. Scientists still debate whether some of the very oldest tiny coiled shells were true snails. [1][2][23]
- **How does a snail become a fossil?** The shell must be buried quickly by mud, sand or silt, which slows decay. Over thousands to millions of years, minerals such as calcite or silica fill or replace it, or the shell dissolves and leaves a mould. [6][3]
- **Are ammonites fossil snails?** No. Ammonites were cephalopods, relatives of the nautilus, squid and octopus. Their shells had chambers separated by walls, unlike a snail’s single open tube. They died out at the end of the Cretaceous. [8]
- **What is Turritella agate?** It is a dark, silica-rich rock from the Green River Formation of Wyoming, 46–51 million years old. Despite the name, its shells are mostly the extinct freshwater snail Elimia tenera, not the sea snail Turritella. [14]
- **What is a steinkern?** A steinkern (German for “stone core”) is an internal mould: the hardened mud that filled a shell, left behind after the shell itself dissolved. [3]
- **What is Purbeck Marble made of?** Purbeck Marble is an Early Cretaceous limestone from Dorset, packed with shells of the freshwater snail Viviparus. It is not true marble but takes a fine polish, and it was used in many English cathedrals and Westminster Abbey. [25][9][10]
- **Where can I find fossil snails?** Look in sedimentary rocks such as limestone, on fossil beaches, or in museums. On coasts like Dorset, search loose material on the beach, not the cliffs, check the tide times and go with an adult. [16][17][18]
- **Is it allowed to collect fossils?** Often yes, on beaches where codes allow it, but many sites are protected. In West Dorset the code asks you not to dig in the cliffs without permission and to record important finds. Scotland has the Scottish Fossil Code. [17][16][26]

### Fossil snail myths and facts

Tap a card to see if it’s a myth or a fact.

- "Ammonites are fossil snails." **Myth!** Ammonites were cephalopods, relatives of the nautilus, squid and octopus. Their shells were split into chambers by walls, and the animal lived only in the last chamber. They died out at the end of the Cretaceous. Snails are gastropods, a different branch of molluscs. [8][4]
- "“Turritella agate” is made of Turritella sea snails." **Myth!** Wyoming’s famous stone is full of Elimia tenera, an extinct freshwater snail, in rock from an old lake. It was named after the sea snail Turritella because the shells look alike. [14]
- "Purbeck Marble is real marble." **Myth!** It is a limestone, not a metamorphic rock like true marble. It is called marble because it takes a fine polish. It is packed with shells of the freshwater snail Viviparus. [25][10][9]
- "Fossil snails only come from ancient oceans." **Myth!** Most fossils are from sea animals, but snails also lived in lakes, rivers and on land. Purbeck Marble is made of lake snails, and land snails turn up in Ice Age deposits in Cambridgeshire. [6][4][10]
- "A fossil snail is always the real shell turned to stone." **Myth!** Minerals can replace the shell, but often it dissolves and leaves only a mould, or a cast where the mould filled up later. And some shells, like 45-million-year-old Campanile giganteum, still contain their original shell mineral. [3][13]
- "Some fossil snails still show their colour patterns." **Fact!** Under ultraviolet light, some fossil shells glow and reveal old colour patterns. In 25 of 46 Late Jurassic snail and clam species tested from Normandy, patterns appeared. It only works if the shell has not dissolved or recrystallised. [20][22]
- "Snail fossils are older than the Jurassic, the heart of the dinosaur age." **Fact!** Gastropod fossils start in the Cambrian, about 541 million years ago. The Jurassic began about 201 million years ago. Which of the very first shells were true snails is still debated. [1][8][23]
- "You can dig fossils out of any cliff." **Myth!** Many fossil coasts are protected. On the Dorset coast, the code asks collectors not to dig in the cliffs without permission, and cliff falls happen suddenly and without warning. Search loose material on the beach, check the tide and go with an adult. [17][16]

### Fossil snail records

The biggest, fastest and longest-lasting, from the scientists who measured them.

- Longest fossil snail: Campanile giganteum, Longest known (Called the longest gastropod known from the fossil record. It lived in the shallow sea of the Paris Basin about 45 million years ago.) [13][24]
- Fastest-growing fossil snail: Campanile giganteum, >600 mm a year (Measured along the spiral. It added over 300 cm³ of shell a year.) [13][24]
- Oldest glowing colour patterns (2015): Late Jurassic shells, Cordebugle, France, 100 million years older (than the oldest fluorescent shell patterns known before.) [20]
- Long-lasting proteins: Bithynia snail trapdoors (opercula), >30 million years (Original amino acids survive in Eocene opercula made of calcite.) [5]
- Biggest mollusc group: Gastropods, ≈80% (of living mollusc species, with more than 62,000 described.) [2]
- Widest range of homes: Gastropods, 5 km deep to 6,000 m high (From the deep ocean floor to mountain slopes, plus lakes and ponds.) [4]

### A timeline of Earth, told by fossil snails

Some big moments in the 541-million-year story of snail fossils. Ma means millions of years ago.

- **541 Ma**: Cambrian: first snail shells. The gastropod fossil record begins. Some of the very oldest tiny coiled shells, like Aldanella, may not be true snails at all. [1][23]
- **Devonian**: Colours that last. Colour patterns are occasionally preserved in snail fossils from this far back. [1]
- **201 Ma**: The Jurassic begins. Ammonites and snails share the seas. [8]
- **Late Jurassic**: Glowing patterns. Shells from Cordebugle, Normandy, still show colour bands under UV light. [20]
- **Early Cretaceous**: Purbeck lakes. Warm lagoons and lakes in southern England fill with Viviparus snails, later quarried as Purbeck Marble. [11][9][25]
- **66 Ma**: Ammonites vanish. Ammonites and dinosaurs die out at the end of the Cretaceous. Snails carry on and become the most common molluscs. [11][4]
- **51–46 Ma**: Wyoming lake snails. Elimia tenera lives in an ancient lake. Its shells become “Turritella agate”. [14]
- **45 Ma**: Giant snails in a hot sea. Campanile giganteum grows in the Paris Basin, in seas over 30 °C in spring and autumn. [13][24]
- **6.6–4.8 Ma**: Reef cone snails. Cone snails on Caribbean reefs leave shells whose patterns glow under UV today. [22]
- **Ice Age**: Snails as clocks. Bithynia trapdoors help date British river deposits, and land snails hint at cool, wet spells. [5][4]
- **Today**: 62,000+ species. Gastropods live from the deep sea to mountains, and their shells keep becoming fossils. [2][4]

### How a snail becomes a fossil

Fossilisation is rare. It needs the right place, the right minerals and a lot of time.

- **Step 1**: A snail dies. Its soft body rots away quickly. The hard shell lasts much longer. [3]
- **Step 2**: Quick burial. Mud, sand or silt covers the shell. This happens most easily under water, especially in the sea. [6][3]
- **Step 3**: Decay slows. Under the sediment there is little oxygen, so the shell is protected. [6]
- **Step 4**: Minerals move in. Mineral-rich water seeps through, filling spaces and sometimes replacing the shell with calcite, silica or pyrite. [3][12]
- **Step 5**: Mould or cast. If the shell dissolves, it leaves a mould. The mud inside becomes an internal mould; a hollow filled later becomes a cast. [3]
- **Step 6**: Layers pile up. More layers settle on top. The lowest layers are the oldest. [7]
- **Step 7**: Time. Turning to stone can take thousands or even millions of years. [6]
- **Step 8**: Found. Erosion uncovers the fossil. On coasts like Charmouth, the sea destroys fossils if nobody collects them. [16]

### What fossil snails tell us

A fossil snail is a tiny record of the water, weather and time it lived in.

- **≈24 °C** Eocene winter sea, Paris Basin. Chemistry in 45-million-year-old Campanile shells shows mild, wet winters and seas over 30 °C in spring and autumn: a monsoon-like climate. [24]
- **Weather** recorded in one shell. Campanile grew so fast that one shell holds weather-scale changes, not just seasons. [13][24]
- **3 waters** fresh, brackish and sea. Purbeck layers swap between freshwater, brackish and sea deposits. Lake snails mark the fresh water. [9][10]
- **>30 Myr** amino acids kept. Proteins locked in Bithynia trapdoors help date British Ice Age river deposits. [5]
- **Cool and wet** land-snail weather. The land snail Helix nemoralis from Ice Age Cambridgeshire was active in cool, wet times and hid in hot, dry ones. [4]

Fossil snails are one clue among many: scientists combine them with other fossils, rock types and chemistry.

### Fossil snail vs ammonite vs living snail

Coiled shells can look alike. Here is how to tell them apart.

| | Fossil snail | Ammonite | Living snail |
|---|---|---|---|
| Animal group [4][8] | Gastropod (mollusc) | Cephalopod (mollusc), relative of nautilus, squid and octopus | Gastropod (mollusc) |
| Inside the shell [1][8] | One open spiral tube | Chambers split by walls; animal lived in the last one | One open spiral tube |
| Typical coil [1][8] | Usually a coiled spire, mostly coiling to the right | Mostly a flat coil, like a nautilus | Usually a spire, mostly coiling to the right |
| Where it lived [4][8] | Seas, lakes, rivers and land | Seas only | Deep sea to 6,000 m up, fresh water and land |
| When [1][8] | Cambrian (≈541 Ma) to the recent past | Died out ≈66 Ma | Today |
| Use for dating rocks [5][8] | Some uses, e.g. amino acids in Bithynia trapdoors | Excellent guide fossils | — |

Both snails and ammonites built shells from calcium carbonate, which is why both fossilise so well.

### Protecting fossil snail sites

Fossils are not on the IUCN Red List, but the best fossil sites are protected, and collecting codes help keep finds safe for science.

- **IUCN Red List:** Not Evaluated (NE) (Trend unknown). Fossil snails are protected through their sites instead. The Dorset coast is a Site of Special Scientific Interest and part of a World Heritage Site, and Scotland has its own fossil code. [17][19][26]
- Not evaluated: the Red List covers living species
- **Threat: Digging in cliffs** (Not allowed): The West Dorset code asks collectors not to dig in the cliffs without permission. Those who do may be treated as stealing fossils. [17]
- **Threat: Lost to the sea** (Daily): On eroding coasts, fossils are uncovered every day. If nobody collects them, the sea destroys them. [16]
- **Threat: Finite sites**: Some sites, such as caves or old mine tips, hold only so many fossils. Collecting there can damage or destroy them. [16]
- **Threat: Unrecorded finds**: Important fossils need a record of the exact place, rock layer, date and a photo so scientists can use them. [17]
- **Helping: World Heritage** (155 km): The Dorset and East Devon Coast covers about 185 million years of Earth history. [19]
- **Helping: SSSI protection** (SSSI): Natural England designated the West Dorset coast a Site of Special Scientific Interest for its geology, fossils and landslides. [17]
- **Helping: Collecting codes**: The West Dorset code and the Scottish Fossil Code set out how to collect, identify, look after and store fossils responsibly. [17][26]
- **Helping: Recording finds**: The Charmouth Heritage Coast Centre records important finds and then hands them back to the collector. [16][17]

### Fossil types

- **Shell fossil**: The whole shell survives, often turned to calcite or replaced by minerals, but sometimes with its original aragonite and even mother-of-pearl. (Common in limestones and shelly clays) [3][13]
- **Steinkern (internal mould)**: A smooth stone spiral: the hardened mud that filled the shell, left behind after the shell dissolved. (Common where shells dissolved away) [3]
- **‘Turritella agate’**: Dark, glassy chert crowded with small, high-spired shells of the lake snail Elimia tenera, set in chalcedony. (46–51 million years old) [14]
- **Pyritised fossil**: A brassy, metallic shell of pyrite (fool’s gold), formed in oxygen-poor mud. (Rare for snails in some Jurassic clays, such as Normandy’s Vaches Noires) [12][21]

### Fossil snail quiz

1. Which group do snails belong to? **Gastropods.** Snails are gastropods, about 80% of living mollusc species. [2]
2. Ammonites were closest to which living animals? **Nautilus, squid and octopus.** Ammonites were cephalopods, relatives of the nautilus, squid and octopus. [8]
3. What is a steinkern? **An internal mould of a shell.** It is the hardened mud that filled a shell, left after the shell dissolved. [3]
4. Which snail fills Wyoming’s “Turritella agate”? **Elimia tenera.** The shells are the extinct freshwater snail Elimia tenera, not Turritella. [14]
5. What is Purbeck Marble really? **A limestone full of freshwater snails.** It is a limestone packed with Viviparus shells that takes a fine polish. [25][10]
6. About what share of fossils found come from sea animals? **99%.** Around 99%, because the sea is where remains get buried fastest. [6]
7. How can scientists see hidden colour patterns on some fossil shells? **Ultraviolet light.** Under UV light, some shells glow and show their old patterns. [20]
8. Where should you look for fossils on the Dorset coast? **Loose material on the beach.** The code says the best place is loose material on the beach, not the cliffs. [16]
9. Which is the fastest-growing snail known from fossils? **Campanile giganteum.** Campanile giganteum grew more than 600 mm a year along its spiral. [13]
10. Which mineral is “fool’s gold”? **Pyrite.** Pyrite, an iron sulfide, can replace shells in oxygen-poor mud. [12]
11. In undisturbed rock layers, which layer is oldest? **The bottom one.** The bottom layer was laid down first, so it is the oldest. [7]
12. How long is the Dorset and East Devon World Heritage coast? **155 km.** It runs for 155 km and shows about 185 million years of Earth history. [19]

### Sources (checked 2026-10-16)

1. [Paleontological Research Institution, Digital Atlas of Ancient Life. Class Gastropoda.](https://www.digitalatlasofancientlife.org/learn/mollusca/gastropoda/)
2. [University of California Museum of Paleontology. The Gastropoda.](https://ucmp.berkeley.edu/taxa/inverts/mollusca/gastropoda.php)
3. [British Geological Survey. Fossils (Discovering Geology).](https://www.bgs.ac.uk/discovering-geology/fossils-and-geological-time/fossils/)
4. [British Geological Survey. Gastropods (Discovering Geology).](https://www.bgs.ac.uk/discovering-geology/fossils-and-geological-time/gastropods/)
5. [Penkman KEH, Preece RC, Bridgland DR, et al. (2013). An aminostratigraphy for the British Quaternary based on Bithynia opercula. Quaternary Science Reviews 61:111–134.](https://doi.org/10.1016/j.quascirev.2012.10.046)
6. [Hendry L. How are dinosaur fossils formed? Natural History Museum, London.](https://www.nhm.ac.uk/discover/how-are-fossils-formed.html)
7. [US Geological Survey. Geologic Time: Relative Time Scale.](https://pubs.usgs.gov/gip/geotime/relative.html)
8. [British Geological Survey. Ammonites (Discovering Geology).](https://www.bgs.ac.uk/discovering-geology/fossils-and-geological-time/ammonites/)
9. [British Geological Survey. BGS Lexicon of Named Rock Units: Purbeck Group.](https://webapps.bgs.ac.uk/lexicon/lexicon.cfm?pub=PB)
10. [West I. Durlston Bay, Swanage, Dorset. Geology of the Wessex Coast (University of Southampton).](https://wessexcoastgeology.soton.ac.uk/Durlston-Bay-Peveril-Point.htm)
11. [British Geological Survey. Geological timechart.](https://www.bgs.ac.uk/discovering-geology/fossils-and-geological-time/geological-timechart/)
12. [Dhami NK, Greenwood PF, Poropat SF, et al. (2023). Microbially mediated fossil concretions and their characterization by the latest methodologies: a review. Frontiers in Microbiology 14:1225411.](https://doi.org/10.3389/fmicb.2023.1225411)
13. [de Winter NJ, Vellekoop J, Clark AJ, et al. (2020). The giant marine gastropod Campanile giganteum (Lamarck, 1804) as a high-resolution archive of seasonality in the Eocene greenhouse world. Geochemistry, Geophysics, Geosystems 21:e2019GC008794.](https://doi.org/10.1029/2019GC008794)
14. [Wikipedia. Elimia tenera ('Turritella agate').](https://en.wikipedia.org/wiki/Elimia_tenera)
15. [Jacobs GS, Jacquet SM, Selly T, Schiffbauer JD, Huntley JW (2024). Resolving taphonomic and preparation biases in silicified faunas through paired acid residues and X-ray microscopy. PeerJ 12:e16767.](https://doi.org/10.7717/peerj.16767)
16. [Charmouth Heritage Coast Centre. The Fossil Collecting Code.](https://charmouth.org/chcc/the-fossil-collecting-code/)
17. [West Dorset Fossil Collecting Code of Conduct (Charmouth Heritage Coast Centre, PDF).](https://charmouth.org/chcc/wp-content/uploads/2023/05/West-Dorset-Fossil-Collecting-Code-of-Conduct.pdf)
18. [Charmouth Heritage Coast Centre. Seashore Code.](https://charmouth.org/chcc/seashore-code/)
19. [UNESCO World Heritage Centre. Dorset and East Devon Coast.](https://whc.unesco.org/en/list/1029)
20. [Caze B, Merle D, Schneider S (2015). UV light reveals the diversity of Jurassic shell colour patterns: examples from the Cordebugle Lagerstätte (Calvados, France). PLoS ONE 10:e0126745.](https://doi.org/10.1371/journal.pone.0126745)
21. [Beaufils S, Vullo R, Gendry D, et al. (2026). Composition and paleoecology of the mid-Jurassic bony fish assemblage of the Vaches Noires cliffs (Normandy, France). PLoS ONE.](https://doi.org/10.1371/journal.pone.0344519)
22. [Hendricks JR (2015). Glowing seashells: diversity of fossilized coloration patterns on coral reef-associated cone snail shells from the Neogene of the Dominican Republic. PLoS ONE 10:e0120924.](https://doi.org/10.1371/journal.pone.0120924)
23. [Dzik J, Mazurek D (2013). Affinities of the alleged earliest Cambrian gastropod Aldanella. Canadian Journal of Zoology 91:914–923.](https://doi.org/10.1139/cjz-2013-0119)
24. [Van Horebeek N, de Winter NJ, Baatsen M, et al. (2025). A European monsoon-like climate in a warmhouse world. Nature Communications 16:9207.](https://doi.org/10.1038/s41467-025-64241-0)
25. [Wikipedia. Purbeck Marble.](https://en.wikipedia.org/wiki/Purbeck_Marble)
26. [NatureScot. Scottish Fossil Code.](https://www.nature.scot/scottish-fossil-code)

## Measurements & details

- **Length:** 0.01-0.3 m
- **Weight:** 0.001-0.5 kg
- **Era:** Cambrian to today

## Diet & Feeding

Snails eat in many ways: some graze on algae and plants, some eat other animals and some feed on dead matter.

- **Primary Foods:** Ancient Algae, Small animals, Decaying Plant Matter
- **Foraging Method:** Foraging

## Ecological connections

- **Eaten by:** Mosasaur (*Mosasaurus hoffmanni*) — Crushed shells of ancient snails may have been part of its diet.
- **Eaten by:** Mesozoic Shark (*Asteracanthus magnus*) — Some ancient sharks may have used powerful jaws to crush hard-shelled prey like snails.

## Traits

- [Spotted](https://www.snappit.app/explore/traits/spotted): Marked with spots or patches of a different color.
- [Ancient](https://www.snappit.app/explore/traits/ancient): Ancient refers to organisms, objects, or geological formations that have existed for an extremely long period.
- [Artifact](https://www.snappit.app/explore/traits/artifact): An artifact is an object made or modified by human culture, typically of historical or archaeological interest.
- [Fossil](https://www.snappit.app/explore/traits/fossil): A fossil is the preserved remains or traces of an ancient organism embedded in rock or other geological deposits.
- [Miniature](https://www.snappit.app/explore/traits/miniature): Pertaining to species that are significantly smaller than typical or average for their kind.

## Collections

- [Ancient](https://www.snappit.app/explore/collections/ancient)

## Safety

**Danger:** 1/5 · Very low

Search loose stones on the beach and never dig in cliffs. Check the tide, keep well away from cliffs and go with an adult.

## Frequently Asked Questions

### How to identify Fossilized Snail?

Compare skull shape, horns, plates, limbs, posture and tail. Museum models and toys can mix features or follow outdated reconstructions. Dinosaur Identifier: upload a photo and compare the visible details.

### How long is Fossilized Snail?

0.01-0.3 m

### How much does Fossilized Snail weigh?

0.001-0.5 kg

### What does Fossilized Snail eat?

Snails eat in many ways: some graze on algae and plants, some eat other animals and some feed on dead matter.

### What geologic era did Fossilized Snail live in?

Cambrian to today

## More Ancient

- [Tyrannosaurus rex](https://www.snappit.app/explore/tyrannosaurus-rex) (*Tyrannosaurus rex*)
- [Triceratops](https://www.snappit.app/explore/triceratops) (*Triceratops horridus*)
- [Stegosaurus](https://www.snappit.app/explore/stegosaurus) (*Stegosaurus stenops*)
- [Brachiosaurus](https://www.snappit.app/explore/brachiosaurus) (*Brachiosaurus altithorax*)

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Source: [Fossilized Snail: Facts & Places to See — Snappit](https://www.snappit.app/explore/fossilized-snail)