**Seashell Identification Chart — Match by Shape, Size and Coast**

> Free seashell identification key for 29 common shells of the Atlantic, Gulf and Pacific coasts. Filter by shape, size, colour and which coast you were on.

Source: https://orvik.app/tools/seashell-identifier/ · updated: 2026-09-04

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3. Sky, coast & ground

Sky, coast & ground

# What shell did I find on the beach?

Start with the split that organises the whole subject: **one piece or two?** A single coiled or conical shell is a gastropod — a snail. A matching pair, or one half of a pair, is a bivalve. That answer plus the coast you were standing on cuts the list to a handful.

Entries **29** Filters **4** Updated **2026-09-04** Cost **Free, no account**

Narrow it down

Clear all

Search shells by name

Basic form

Spiral or coiled Cone or cap-shaped Two halves, fan-shaped Two halves, oval or oblong Flat disc None of these

Size

Under 2 cm 2–5 cm 5–10 cm Over 10 cm

Surface

Strong ribs or ridges Smooth Spines or knobs Patterned or zigzagged Pearly inside Holes or a slot

Coast

Atlantic — New England to Carolina Atlantic — Florida Gulf of Mexico Pacific Northwest Europe

Showing all 29 shells

1. ### Atlantic bay scallop Argopecten irradians A fan with 17 to 18 strong rounded ribs and a small square "ear" on each side of the hinge, in mottled grey, orange or purple. The living animal has a row of blue eyes along the mantle edge. Size 5–8 cm Where Eelgrass beds from Massachusetts to Texas. In the record 14,485 georeferenced records · half of them Feb–Jul · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2285856)

2. ### Calico scallop Argopecten gibbus A small deeply cupped scallop mottled in white, pink and maroon in a broken calico pattern, with about 20 ribs. The most abundant shell on many Florida beaches. Size 3–6 cm Where North Carolina to Brazil. In the record 5,660 georeferenced records · half of them Jan–Jun · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2285862)

3. ### Atlantic jingle shell Anomia simplex Thin, translucent, warped and metallic gold, orange or silver, light enough to be almost weightless. The lower valve has a hole where the animal cemented itself to a rock. A handful jingles like coins. Size 2–5 cm Where Nova Scotia to Brazil. In the record 8,675 georeferenced records · half of them Jan–May · most distinctive in May · mostly from the United States [check on GBIF](https://www.gbif.org/species/5188927)

4. ### Eastern oyster Crassostrea virginica Thick, heavy, irregular and layered, taking the shape of whatever it grew on, chalky grey outside and porcelain white inside with a single purple muscle scar. Size 5–20 cm Where The Gulf of St Lawrence to the Gulf of Mexico. In the record 15,837 georeferenced records · half of them Jan–Jun · most distinctive in April · mostly from the United States [check on GBIF](https://www.gbif.org/species/2286079)

5. ### Blue mussel Mytilus edulis A smooth blue-black wedge pointed at one end, glossy when wet, pearly violet-white inside, usually still attached to others by tough byssal threads. Size 4–10 cm Where Cold rocky coasts of the North Atlantic and Pacific. In the record 232,395 georeferenced records · half of them Aug–Oct · most distinctive in September · mostly from Sweden [check on GBIF](https://www.gbif.org/species/8288896)

6. ### Atlantic surf clam Spisula solidissima A large heavy triangular-oval white clam with a smooth chalky exterior and a spoon-shaped pit inside the hinge. The big empty shells used as ashtrays on the northeast coast. Size 12–20 cm Where Nova Scotia to North Carolina. In the record 7,477 georeferenced records · half of them Apr–Aug · most distinctive in April · mostly from the United States [check on GBIF](https://www.gbif.org/species/5188982)

7. ### Quahog and hard clam Mercenaria mercenaria Thick, heavy and rounded-triangular with fine concentric growth ridges, dull grey-white outside and often edged deep purple inside. That purple lip was carved into wampum. Size 7–13 cm Where The Gulf of St Lawrence to Florida. In the record 7,142 georeferenced records · half of them Mar–Jul · most distinctive in April · mostly from the United States [check on GBIF](https://www.gbif.org/species/2287668)

8. ### Atlantic razor clam Handle with care Ensis directus Long, narrow and slightly curved like an old straight razor, glossy olive-brown with a varnished periostracum. Edges are genuinely sharp. Size 10–25 cm Where The North Atlantic; introduced and abundant in Europe. Risk Broken razor shells cut bare feet on tidal flats. They are the main reason to wear something on a mudflat. In the record 8,784 georeferenced records · half of them Feb–Jun · most distinctive in February · mostly from the Netherlands [check on GBIF](https://www.gbif.org/species/2287249)

9. ### Coquina Donax variabilis Tiny wedge-shaped shells in every colour combination there is — pink, yellow, blue, purple, striped, rayed — no two alike. Living animals burrow back into the swash within seconds of a wave. Size 1–2.5 cm Where Virginia to Texas. In the record 5,185 georeferenced records · half of them Mar–Jul · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/5189101)

10. ### Angel wing Cyrtopleura costata Pure white, thin, brittle and elongated, with about 26 strongly beaded radiating ribs. Found whole only rarely, because the animal lives a metre deep in mud and the shell breaks on the way out. Size 10–18 cm Where Massachusetts to Brazil. In the record 2,432 georeferenced records · half of them Oct–Feb · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2288749)

11. ### Lettered olive Americoliva sayana A glossy cylindrical shell with a short spire and a long narrow aperture, cream with fine brown zigzag markings that look like handwriting. South Carolina's state shell. Size 5–7 cm Where North Carolina to Texas. In the record 596 georeferenced records · half of them Feb–May · most distinctive in February · mostly from the United States [check on GBIF](https://www.gbif.org/species/8157902)

12. ### Shark eye moon snail Neverita duplicata A smooth flattened globe, grey-blue with a dark button of callus in the centre of the underside that gives it the eye look. Drills neat countersunk holes in other shells to eat them. Size 4–8 cm Where Massachusetts to Texas. Confused with Any shell you find with a perfect round bevelled hole was killed by one of these. That hole is a moon snail's signature. In the record 18,351 georeferenced records · half of them Jan–Jun · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2300326)

13. left-handed. hold it spire up: the opening is on your left, which almost no other shell does."> ### Lightning whelk Sinistrofulgur perversum A large pear-shaped whelk with knobs on the shoulder and brown lightning-bolt streaks — and it coils **left-handed**. Hold it spire up: the opening is on your left, which almost no other shell does. Size 10–30 cm Where The Gulf of Mexico and southeastern Atlantic. In the record 351 georeferenced records · half of them Jan–Apr · mostly from the United States [check on GBIF](https://www.gbif.org/species/7575028)

14. ### Knobbed whelk Busycon carica Large, pear-shaped, with a crown of blunt knobs around the shoulder and a bright orange interior. Coils right-handed, unlike the lightning whelk. New Jersey and Georgia both use it as a state shell. Size 10–23 cm Where Massachusetts to Florida. In the record 5,164 georeferenced records · half of them Mar–Jul · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2302937)

15. ### Channeled whelk Busycotypus canaliculatus Pear-shaped with a deep square-cut channel spiralling along the suture between the whorls, and no knobs. Often found with a long string of papery egg capsules like a coiled zipper. Size 10–18 cm Where Cape Cod to Florida. In the record 3,101 georeferenced records · half of them Apr–Aug · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2302958)

16. ### Florida fighting conch Strombus alatus A heavy stout conch with a flaring lip and a row of blunt spines on the shoulder, orange to brown. The notch near the front of the aperture is where the animal's eye stalk sticks out. Size 5–10 cm Where North Carolina to Texas. In the record 2,211 georeferenced records · half of them Feb–Jun · most distinctive in April · mostly from the United States [check on GBIF](https://www.gbif.org/species/5192685)

17. ### Queen conch Handle with care Aliger gigas Very large with a broad flaring lip and a glossy pink to peach interior. The classic shell held to the ear. Size 15–30 cm Where Florida and the Caribbean. Risk Protected in Florida — it is illegal to take a live queen conch there, and the species is listed under CITES. Empty shells are also restricted in some jurisdictions. In the record 9,027 georeferenced records · half of them May–Aug · most distinctive in March · mostly from Puerto Rico [check on GBIF](https://www.gbif.org/species/10903982)

18. ### Atlantic slipper shell Crepidula fornicata An oval cap with a shelf across half the underside, like a boat with a deck — hence the alternative name of boat shell. Stacks of them grow one on another, and every animal in the stack changes sex as it ages. Size 2–5 cm Where Native to the western Atlantic; invasive in Europe and on the Pacific coast. In the record 81,342 georeferenced records · half of them Feb–Jul · most distinctive in December · mostly from the Netherlands [check on GBIF](https://www.gbif.org/species/5192789)

19. ### Limpet Patella and Lottia species A simple ribbed cone with an oval opening and no coil at all. Each limpet grinds a scar into the rock that its shell fits exactly, and returns to it after every feeding trip. Size 2–6 cm Where Rocky shores worldwide.
20. ### Abalone Handle with care Haliotis species A flattened ear-shaped shell with a row of open respiratory holes along one edge and a brilliant iridescent nacre interior. Rough and encrusted outside, spectacular inside. Size 10–25 cm Where The Pacific coast from Alaska to Mexico, and worldwide. Risk Heavily regulated. Taking abalone is banned or tightly licensed on most of the US Pacific coast, and possession rules can apply to empty shells. In the record 1,932,070 georeferenced records · half of them Nov–Nov · most distinctive in November · mostly from the United States [check on GBIF](https://www.gbif.org/species/2293068)

21. ### Olympia and Pacific oyster Ostrea lurida, Magallana gigas Heavy, ruffled and irregular with sharp frilled edges, grey-white outside and smooth inside. The introduced Pacific oyster is much larger and more elongated than the native Olympia. Size 5–25 cm Where The Pacific coast of North America. In the record 11,519 georeferenced records · half of them May–Jun · most distinctive in June · mostly from Canada [check on GBIF](https://www.gbif.org/species/2286067)

22. ### Sand dollar Handle with care Echinarachnius parma, Mellita species A flat white disc with a five-petalled flower pattern on top. It is not a shell at all but the internal skeleton of a burrowing sea urchin, and a living one is purple-brown and covered in fine moving spines. Size 5–10 cm Where Sandy bottoms on all US coasts. Risk A brown, fuzzy or purple sand dollar is alive. Put it back in the water. Only the bleached white ones are dead. In the record 23,218 georeferenced records · half of them Aug–Sep · most distinctive in August · mostly from Canada [check on GBIF](https://www.gbif.org/species/2279041)

23. ### Common periwinkle Littorina littorea A small, solid, dark grey-brown spiral with a pointed spire and a thick round opening. The most abundant snail on northern rocky shores. Size 1–3 cm Where Rocky shores of the North Atlantic; introduced to North America. In the record 59,882 georeferenced records · half of them May–Aug · most distinctive in July · mostly from the United Kingdom [check on GBIF](https://www.gbif.org/species/2301117)

24. ### Dog whelk Nucella lapillus A thick ribbed spiral in white, yellow or banded brown, with a short spire and a notched aperture. Colour depends on diet — mussel-eaters are brown, barnacle-eaters white. Size 2–4 cm Where Rocky North Atlantic shores. In the record 46,493 georeferenced records · half of them Jun–Sep · most distinctive in July · mostly from the United Kingdom [check on GBIF](https://www.gbif.org/species/5193449)

25. ### Common cockle Cerastoderma edule A near-circular cream shell with about 24 strong radiating ribs and a deeply cupped profile, so the two halves together make a heart shape seen end-on. Size 3–5 cm Where Sandy shores across northwest Europe. In the record 101,430 georeferenced records · half of them Mar–Aug · most distinctive in January · mostly from the Netherlands [check on GBIF](https://www.gbif.org/species/2286583)

26. ### Auger and turret shells Terebridae, Turritellidae Long, slender, sharply pointed spires with many tight whorls — the shape of a screw or a church spire. Augers are smooth and patterned; turret shells are strongly ribbed. Size 3–12 cm Where Warm sandy coasts. In the record 47,732 georeferenced records · half of them Jan–Jun · most distinctive in February · mostly from the United States [check on GBIF](https://www.gbif.org/species/2685)

27. ### Cowrie Cypraeidae A glossy egg with a long narrow toothed slit along the flat underside and no visible spire at all — the mantle polishes the outside continuously while the animal is alive. Size 1–6 cm Where Warm seas worldwide; small species reach Florida and the Gulf. In the record 373,880 georeferenced records · half of them Nov–Nov · most distinctive in November · mostly from the United States [check on GBIF](https://www.gbif.org/species/2675)

28. ### Common whelk and egg case Buccinum undatum A solid ribbed spiral with a pointed spire and a flared opening, in dull cream. The papery mass of hundreds of fused capsules washed up beside it — often called a sea wash ball — is its egg case. Size 6–11 cm Where The North Atlantic. In the record 54,997 georeferenced records · half of them Apr–Aug · most distinctive in February · mostly from the United Kingdom [check on GBIF](https://www.gbif.org/species/2305073)

29. ### Skate egg case Rajidae Not a shell: a black leathery rectangular purse with a curved horn at each corner. Called a mermaid's purse, and it held a single skate embryo. Empty ones with a split at one end hatched successfully. Size 5–12 cm Where All temperate coasts. In the record 832,834 georeferenced records · half of them Jul–Oct · most distinctive in March · mostly from the United States [check on GBIF](https://www.gbif.org/species/5877)

Nothing in this key matches every filter at once. That usually means one observation is
off — a colour read in shade, or a size guessed rather than measured. Clear the filter you
are least sure about and look again.

## One piece or two

The first cut in shell identification is not shape or colour but the animal that built it, and it is visible instantly.

**Gastropods** — snails — build one continuous coiled tube, growing at the open end. Anything spiral, conical or cap-shaped is a gastropod, including limpets and abalone, whose coil is flattened almost out of existence.

**Bivalves** — clams, mussels, oysters, scallops — build two hinged halves. On a beach you almost always find one half, so learn to recognise the **hinge**: a straight edge with interlocking teeth and, on many species, a scar where the closing muscle attached. That hinge edge tells you it is half of a pair even when the pair is long separated.

Two things on a beach are commonly called shells and are neither. A **sand dollar** is the internal skeleton of a burrowing sea urchin. A **mermaid's purse** is the leathery egg case of a skate. Both are worth knowing because both prompt the same question every summer.

Once you have the group, the useful characters are the ribs, the shape of the aperture and the size — and the coast, which for most species is more restrictive than anything about the shell itself.

## The stories a shell carries

Beachcombing gets considerably more interesting once you can read what happened to a shell before it reached you.

**A neat round countersunk hole** near the hinge or shoulder means a moon snail or a drilling whelk ate the animal. The predator rasps a hole with its radula and softens it with acid, and the bevelled edge is diagnostic. Shells with these holes are the commonest kind on many Atlantic beaches, and each one is a record of a predation event.

**A chipped and broken aperture** usually means a crab attacked it and failed, or succeeded. Repaired scars running across the growth lines show an attack the animal survived.

**Fine branching white tubes cemented to the outside** are serpulid worms; small volcano-shaped cones are barnacles; a lacy crust is a bryozoan colony. All of these settled while the shell was still on the seabed, and heavy encrustation means it lay there a long time.

**A worn, chalky, rounded shell with the colour gone** has been rolled in surf for a long time, possibly years. A glossy shell with sharp edges arrived recently. This is why the best shelling is after a storm at low tide — the storm delivers material that has not yet been ground down.

**Left-handed coiling** is worth knowing because it is rare. Hold a spiral shell with the spire up and the opening facing you: if the aperture is on the right, the shell is dextral, like almost every gastropod on Earth. The lightning whelk of the Gulf coast is one of the few common left-handed shells, and it is instantly recognisable once you know to look.

## When to leave it, and what the rules are

The most important question on a beach is whether the animal is still in it.

*Checking whether a shell is occupied before you pocket it.*

| Shell | Alive if… | Do |
| --- | --- | --- |
| Spiral shells | A hard door, the operculum, seals the opening; or legs and eyes emerge; or it smells | Return it to the water where you found it |
| Any spiral shell | It moves in your hand — a hermit crab is inside | Put it straight back. Hermit crabs are limited by shell supply |
| Bivalves | The two halves are still joined and closed | Return it. A joined pair usually means the animal is inside |
| Sand dollar | Brown, purple, or fuzzy with fine spines | Return it to the water. Only bleached white ones are dead |
| Starfish and urchins | Any movement of tube feet or spines | Return it |

The legal position varies far more than most people expect. Several US states and many national and state parks prohibit collecting live shells and some prohibit collecting empty ones. Sanibel Island in Florida — the most famous shelling beach in North America — banned live shelling outright in 1995. Queen conch is protected in Florida and listed under CITES, abalone is tightly regulated on the Pacific coast, and taking any shell from a National Park is generally prohibited. Look up the local rule before you fill a bucket.

Beyond the law there is a straightforward ecological argument. Empty shells are habitat: hermit crabs need them, small fish and octopus shelter in them, and they break down into the calcium carbonate that beaches and reefs are made of. A study on the Spanish coast found a 30-year decline in shell abundance tracking tourist numbers, with measurable effects on the organisms that depend on them. Photographing a shell and leaving it is not sentimentality.

## Finding better shells

Shelling rewards timing far more than effort.

- **Go at low tide, ideally a spring tide.** The lowest tides of the month expose ground that is usually underwater, and the tide tables are free.
- **Go the morning after a storm or a strong onshore blow.** This is the single biggest factor. Winter storms on the Gulf and Atlantic coasts deliver material that has been on the seabed for years.
- **Work the wrack line**, the ribbon of seaweed and debris left at high water, and then the swash zone where waves are actively sorting material by density.
- **Look for the sorted patches.** Beaches sort by size and weight, so shells collect in specific places — behind a groyne, at the inside of a curve, at the ends of a beach. Once you find the patch, work it rather than walking.
- **Look down-drift of a hard structure.** Jetties, groynes and rock outcrops trap material moving along the coast.

To clean what you keep: soak in a 50:50 mix of water and household bleach for a few hours to remove organic residue, rinse well, dry, and rub with a little mineral oil to restore the colour that drying takes out. Do not boil delicate shells — thermal shock cracks them — and do not bleach anything with a natural periostracum you want to keep, because bleach strips it.

## What this key covers

29 entries covering the shells people actually pick up on North American and northwest European beaches, plus the two things on the strandline that are not shells at all. There are over 100,000 described mollusc species and any Florida beach can produce several hundred, so a key this size is a starting point rather than a field guide.

Two limits are worth stating. Many families — augers, turret shells, cowries, tellins, arks — contain dozens of similar species separable only by fine sculpture, and this key names the family where that is true. And beach wear removes exactly the characters identification depends on: a rolled and bleached shell may not be identifiable by anyone.

For a genuinely good identification, photograph the shell from three angles — aperture facing you, the back, and the hinge or underside — with a ruler in frame, and note the beach and the date. Regional shell clubs, museum malacology departments and iNaturalist all identify submissions, and the location is what makes it possible.

## What the observation record shows

Every entry in this key that carries a scientific name is matched against

- [GBIF](https://www.gbif.org/), the
international register of biodiversity records, and against

- [iNaturalist](https://www.inaturalist.org/).
That puts a hard number behind 28 of the 29shells here:
**725,754 georeferenced records** across the 24 entries that resolve to a single species, spanning 23 families, the oldest of them collected in
1877. The snapshot was taken on 2026-09-04.

That evidence is not spread evenly, and it is worth knowing before you trust a narrow
result. The five best-recorded shells in this key hold 73%
of all the records between them: Blue mussel alone accounts for
232,395, while Lightning whelk has
351. A common thing is common in the data too, so
when a filter narrows to one frequent entry and one rare one, the frequent one is
usually the answer — and the record count is the quickest way to see which is which.
The same skew applies geographically: 22% of these
records come from the Netherlands, so the key describes what is
reported there far better than it describes anywhere else.

### When these are actually reported

*Half of the 688,837 georeferenced records for these 24 shells fall in April–August alone. The bars are the raw share by month, which mostly measures when people go looking; the line divides each month by the baseline for every species in every Orvik key, so a value above 1.0 means these shells are reported more than the season alone explains, and it peaks in September. Source: GBIF, snapshot 2026-09-04.*

Half of every record for this group falls in April–August.
A raw month count measures two things at once — when the organism is about, and when
people are outdoors with a camera — and the second effect is large enough to give
almost anything a summer peak. The line on the figure divides each month by the
baseline for every species in every Orvik key, which answers a different question:
relative to when people record anything at all, when are these shells recorded?
Values above 1.0 are the months that belong to this group rather than to the season.
On that measure 13 of the 24shells here peak
outside the warm half of the year — Common cockle, Atlantic slipper shell, Common whelk and egg case among them. Those are the ones a seasonal rule of
thumb gets wrong.

### Records behind each entry

Sorted by how much evidence exists, not by how likely you are to meet one. The peak
month is the effort-adjusted figure, and it is left blank wherever the sample is too
thin for the month-to-month wobble to mean anything.

*GBIF and iNaturalist record counts for the 28 named shells in this key,
 snapshot 2026-09-04. Rows above species rank aggregate everything beneath them and
 are not comparable with the rest. Free to reuse with a link to this page.*

| Entry | Accepted name | Rank | GBIF records | Research-grade | Half fall in | Peak, adjusted | Most reported from |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Blue mussel | [Mytilus edulis Linnaeus, 1758](https://www.gbif.org/species/8288896) | species | 232,395 | 35,916 | Aug–Oct | September | Sweden |
| Common cockle | [Cerastoderma edule](https://www.gbif.org/species/2286583) | species | 101,430 | 6,636 | Mar–Aug | January | the Netherlands |
| Atlantic slipper shell | [Crepidula fornicata](https://www.gbif.org/species/5192789) | species | 81,342 | 15,927 | Feb–Jul | December | the Netherlands |
| Common periwinkle | [Littorina littorea](https://www.gbif.org/species/2301117) | species | 59,882 | 22,402 | May–Aug | July | the United Kingdom |
| Common whelk and egg case | [Buccinum undatum Linnaeus, 1758](https://www.gbif.org/species/2305073) | species | 54,997 | 8,734 | Apr–Aug | February | the United Kingdom |
| Dog whelk | [Nucella lapillus](https://www.gbif.org/species/5193449) | species | 46,493 | 10,166 | Jun–Sep | July | the United Kingdom |
| Sand dollar | [Echinarachnius parma](https://www.gbif.org/species/2279041) | species | 23,218 | 1,985 | Aug–Sep | August | Canada |
| Shark eye moon snail | [Neverita duplicata](https://www.gbif.org/species/2300326) | species | 18,351 | 8,137 | Jan–Jun | December | the United States |
| Eastern oyster | [Crassostrea virginica](https://www.gbif.org/species/2286079) | species | 15,837 | 18,265 | Jan–Jun | April | the United States |
| Atlantic bay scallop | [Argopecten irradians](https://www.gbif.org/species/2285856) | species | 14,485 | 7,341 | Feb–Jul | December | the United States |
| Olympia and Pacific oyster | [Ostrea lurida P.P.Carpenter, 1864](https://www.gbif.org/species/2286067) | species | 11,519 | 1,248 | May–Jun | June | Canada |
| Queen conch | [Aliger gigas](https://www.gbif.org/species/10903982) | species | 9,027 | 4,681 | May–Aug | March | Puerto Rico |
| Atlantic razor clam | [Ensis directus](https://www.gbif.org/species/2287249) | species | 8,784 | 6,823 | Feb–Jun | February | the Netherlands |
| Atlantic jingle shell | [Anomia simplex d'Orbigny, 1853](https://www.gbif.org/species/5188927) | species | 8,675 | 5,611 | Jan–May | May | the United States |
| Atlantic surf clam | [Spisula solidissima](https://www.gbif.org/species/5188982) | species | 7,477 | 7,976 | Apr–Aug | April | the United States |
| Quahog and hard clam | [Mercenaria mercenaria](https://www.gbif.org/species/2287668) | species | 7,142 | 10,372 | Mar–Jul | April | the United States |
| Calico scallop | [Argopecten gibbus](https://www.gbif.org/species/2285862) | species | 5,660 | 4,504 | Jan–Jun | December | the United States |
| Coquina | [Donax variabilis Say, 1822](https://www.gbif.org/species/5189101) | species | 5,185 | 5,984 | Mar–Jul | December | the United States |
| Knobbed whelk | [Busycon carica](https://www.gbif.org/species/2302937) | species | 5,164 | 6,701 | Mar–Jul | December | the United States |
| Channeled whelk | [Busycotypus canaliculatus](https://www.gbif.org/species/2302958) | species | 3,101 | 3,558 | Apr–Aug | December | the United States |
| Angel wing | [Cyrtopleura costata](https://www.gbif.org/species/2288749) | species | 2,432 | 2,427 | Oct–Feb | December | the United States |
| Florida fighting conch | [Strombus alatus Gmelin, 1791](https://www.gbif.org/species/5192685) | species | 2,211 | 5,327 | Feb–Jun | April | the United States |
| Lettered olive | [Americoliva sayana](https://www.gbif.org/species/8157902) | species | 596 | — | Feb–May | February | the United States |
| Lightning whelk | [Sinistrofulgur perversum](https://www.gbif.org/species/7575028) | species | 351 | 91 | Jan–Apr | — | the United States |
| Abalone | [Haliotis Linnaeus, 1758](https://www.gbif.org/species/2293068) | genus | 1,932,070 | 30,877 | Nov–Nov | November | the United States |
| Skate egg case | [Rajidae](https://www.gbif.org/species/5877) | family | 832,834 | 20,082 | Jul–Oct | March | the United States |
| Cowrie | [Cypraeidae](https://www.gbif.org/species/2675) | family | 373,880 | 54,178 | Nov–Nov | November | the United States |
| Auger and turret shells | [Terebridae](https://www.gbif.org/species/2685) | family | 47,732 | 8,122 | Jan–Jun | February | the United States |

This table is assembled from open data and is free to reuse with a link back to this
page. The snapshot behind every Orvik key is published as one downloadable file on the

- [open field data](https://orvik.app/data/) page, with each source's licence terms.

## Questions people ask about this

How do I know if a shell is still alive?

For spiral shells, look for a hard door — the operculum — sealing the opening, or for legs and eyes emerging, or any movement, which usually means a hermit crab. For bivalves, two halves still joined and closed almost always means the animal is inside. A sand dollar that is brown, purple or fuzzy with fine spines is alive; only bleached white ones are dead. Anything alive goes back in the water.

Is it legal to take shells from the beach?

It depends entirely on where you are. Many US states restrict or ban taking live shells, and collecting in National Parks is generally prohibited. Sanibel Island in Florida banned live shelling in 1995. Queen conch is protected in Florida and listed under CITES, and abalone is tightly regulated on the Pacific coast. Check the local rule before collecting, and be aware that some rules cover empty shells too.

What made the perfect round hole in my shell?

A predatory snail, most often a moon snail or a drilling whelk. It rasps a hole with its radula while softening the shell with acid, then eats the animal inside. The hole is neatly circular and countersunk — bevelled wider on the outside — which is what distinguishes it from damage. Every shell with one of these holes is a record of a predation event.

Is a sand dollar a shell?

No. It is the internal skeleton, called a test, of a burrowing sea urchin. In life it is covered in short moving spines and is brown or purple; the flat white disc with the five-petalled pattern is what is left after the animal dies and the spines fall off. The petal pattern is where its tube feet emerged.

What is the black leathery thing with horns at the corners?

A skate egg case, commonly called a mermaid's purse. Each one held a single embryo, and the horns anchored it to seaweed or the seabed. If one end is split open, it hatched successfully. In the UK, the Shark Trust runs a recording programme that uses public finds to map where skates and rays breed.

When is the best time to find shells?

Low tide on the morning after a storm or a strong onshore wind, ideally on a spring tide when the water pulls back furthest. Storms lift material off the seabed that has been there for years. Work the wrack line and the swash zone, and look for the places where a beach naturally sorts material — behind groynes, at the inside of curves and at the ends of a beach.

How do I clean seashells?

Soak them for a few hours in a half-and-half mix of water and household bleach to remove organic residue, rinse thoroughly, dry, and rub in a little mineral oil to restore the colour that drying dulls. Do not boil thin or delicate shells, because thermal shock cracks them, and do not bleach anything whose brown outer skin you want to keep — bleach strips it away.

## Still not sure? Point a camera at it

A filter narrows shells down to a shortlist. Orvik reads the photo itself and names the species, with the look-alikes ranked underneath so you can check the call yourself.

- [Get Orvik free](https://orvik.app/app/)

## Keep reading on Orvik

- [Photo identifier tools](https://orvik.app/nature/photo-identifier/)

- [Identify an animal by picture](https://orvik.app/animals/identify-animal-by-picture/)

- [How to identify rocks](https://orvik.app/rocks/identify-rocks/)

- [Fossil identifier](https://orvik.app/rocks/fossil-identifier/)

- [Photo recognition apps](https://orvik.app/nature/photo-recognition-app/)

- [What is this rock?](https://orvik.app/rocks/what-is-this-rock/)

## Other free Orvik tools

- [What cloud is that?](https://orvik.app/tools/cloud-identifier/)
- [What snake did I just see?](https://orvik.app/tools/snake-identifier/)
- [Whose egg is this?](https://orvik.app/tools/bird-egg-identifier/)
- [Which bird did this feather come from?](https://orvik.app/tools/feather-identifier/)
- [What kind of rock is this?](https://orvik.app/tools/rock-identifier/)
- [Which mineral is this?](https://orvik.app/tools/mineral-identifier/)
- [What gemstone is this?](https://orvik.app/tools/gemstone-identifier/)
- [What fossil is this?](https://orvik.app/tools/fossil-identifier/)

## Where the data comes from

- [Smithsonian National Museum of Natural History — invertebrate zoology](https://naturalhistory.si.edu/research/invertebrate-zoology)
- [Bailey-Matthews National Shell Museum, Sanibel](https://www.shellmuseum.org/)
- [NOAA — beachcombing and coastal collecting guidance](https://oceanservice.noaa.gov/)
- [Marine Conservation Society — UK shore identification](https://www.mcsuk.org/)
- [GBIF — Global Biodiversity Information Facility](https://www.gbif.org/)
- [iNaturalist](https://www.inaturalist.org/)

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HTML version: https://orvik.app/tools/seashell-identifier/
Structured data for this site: https://orvik.app/api/v1/openapi.json · https://orvik.app/llms.txt
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