Description

Limestone Ammonite

Limestone Ammonite half from Somerset, United Kingdom

Name: Somerset Ammonites
Age: Jurassic period
Location: Somerset, United Kingdom

These Somerset ammonites are mosly from the Hildoceras family sp., and were founs in Jurassic period limestone deposits near Ilchester in Somerset, which was a tropical ocaen some 190 million – 170 million years ago.

Approx Size: 2-3cm in Diameter

About Ammonites
Ammonites are extinct marine molluscs related to living coleoids like octopuses, squid and cuttlefish.

Ammonites appeared during the Devonian and are excellent index fossil, linking the rock layer in which it is found to specific geologic time periods. The name “ammonite” was inspired by the spiral shape of their fossilized shells which resemble coiled rams’ horns.

Pliny the Elder called Ammonites ‘ammonis cornua’ (“horns of Ammon”) because the Egyptian god Ammon was typically depicted wearing rams’ horns. Often, the name of an ammonite genus ends in -ceras, which is from κέρας (kéras) meaning “horn”.

The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found.