Fossilized Sea Urchin
Scientific Name: Echinoidea
Category: rock
Brief Description
A fossilized echinoid (sea urchin) test, often called a shepherd's crown or fairy loaf, characterized by its rounded, radially symmetrical shape and detailed pore patterns.
Characteristics
Oval to rounded shape with a prominent pattern of radiating lines and tiny dot-like pores (ambulacral and interambulacral plates) that once held tube feet. Typically preserved in limestone or chalk.
Habitat
Marine sedimentary deposits, ancient seabeds, chalk cliffs, and limestone outcrops.
When to Find It
N/A
Conservation Status
N/A
Ecological Role
Fossilized echinoids serve as important index fossils for dating geological strata and provide crucial insights into ancient marine ecosystems.
Easily Confused With
Other round fossils such as brachiopods or crinoids, though sea urchin fossils are distinguished by their distinct five-fold radial symmetry and pore rows.
Observation Tips
Look for them weathering out of limestone or chalk formations, especially after heavy rains wash away loose soil.
Interesting Facts
In folklore, fossilized sea urchins were once thought to be thunderbolts or loaves of bread turned to stone by fairies, and were kept in homes to protect against lightning and bad luck.