Ammonite. Polished sectioned ammonite fossil. Ammonites are extinct marine invertebrates.
Science Photo Library / Alamy Stock Photo
Image ID: B6DRKM
andlt;strongandgt;Ammonite.andlt;/strongandgt; Polished sectioned ammonite fossil.Ammonites are extinct marine invertebrates. Theyfirst appeared in the Late Silurian to EarlyDevonian period (around 400 million years ago) andbecame extinct at the end of the Cretaceous period(65 million years ago).