Rocksday

Ammonite

Coiled shells of extinct squid-like sea creatures that vanished with the dinosaurs.

Ammonite specimen
Photo: Llez (H. Zell)., CC BY-SA 3.0, via Wikimedia Commons

How to identify ammonite

  • Flat spiral shell with ribs.
  • Wavy, frilly suture lines where internal walls met the shell.
  • Often split and polished to show chambers.

Often confused with

Where it's found

  • Jurassic Coast, England
  • Mahajanga, Madagascar
  • Morocco
  • Holzmaden, Germany

Uses

Fossil collecting and decor; key 'index fossils' for dating rocks.

Rock tumbling

Not suitable for tumbling.

Did you know?

Ammonites lived for over 300 million years before dying out 66 million years ago.

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