Sea urchins
Echinoids preserved in chalk and limestone, from dome-shaped to heart-shaped.
Mostly Cretaceous in Britain, with Jurassic forms as well. · Easy to find
What is it?
Fossil sea urchins (echinoids) are found mainly in the Cretaceous Chalk, where they are preserved as flint or chalk casts. Heart urchins such as Micraster and the rounder Echinocorys are the two most commonly recognised British forms.
What does it look like?
Rounded or heart-shaped, usually 3–8 cm, with a five-part star pattern of tiny paired pores across the upper surface. Flint casts are grey to honey coloured; chalk specimens are white and fragile.
How to identify it
- 01The five-rayed petal pattern is the decisive feature — look for it on the domed upper surface.
- 02Flint specimens survive in beach shingle below chalk cliffs long after the chalk has gone.
- 03Chalk specimens are soft when fresh; wrap them and let them dry slowly before cleaning.
Where to find sea urchins in the UK
- 01Ringstead BayDorset · DorsetAmmonites · Bivalves · Sea urchins · GastropodsModerateBeach, CliffExplore location →
- 02Beer BeachDevon · DevonSea urchins · Belemnites · Bivalves · BrachiopodsEasyFamily friendlyBeach, CliffExplore location →
- 03BranscombeDevon · DevonSea urchins · Bivalves · Brachiopods · BelemnitesEasyFamily friendlyBeach, CliffExplore location →
- 04Folkestone WarrenKent · KentAmmonites · Bivalves · Gastropods · BelemnitesModerateBeach, Cliff, Geological siteExplore location →
- 05HunstantonNorfolk · NorfolkBelemnites · Brachiopods · Bivalves · Sea urchinsEasyFamily friendlyBeach, CliffExplore location →
- 06West RuntonNorfolk · NorfolkMammal bones · Sea urchins · Bivalves · Fossilised woodModerateFamily friendlyBeach, Cliff, Geological siteExplore location →
- 07Filey BriggNorth Yorkshire · Yorkshire and the North East coastBrachiopods · Bivalves · Corals · Sea urchinsModerateFamily friendlyBeach, Geological siteExplore location →