Fossil Information Sheet F010
Goniatites
An extinct group of Ammonites, related to the Nautiloids living in the early Devonian period some 400 million years ago, which became extinct in the Permian period (290-248 million years ago).
Part of the larger group of Cephalopods- molluscs which include gastropods and bi-valves.
Like ammonites and nautilus they possessed external shells with internal chambers filled wih gas for buoyancy.
They were free swimming creatures possessing a head and two well-developed eyes, and arms or tentacles.
They were small to medium in size often less than 15cm (6" in diameter) upwards.
They have been predominantly found in North America, Europe, North Africa and Australasia.
Certain limestones in the western republic of Ireland are packed with beautifully formed Goniatite fossils.
They are also found in marine bands of the Pennsylvanian period in Arkansas.
Numbers of Goniatites have also occurred in rocks from the Devonian period in Morocco and they are an important zone, or index fossil, for dating the rocks of that period.
Goniatites in a fossil mosaic table top - a genuine one-off of fossilised Orthoceras around the edge of a central plate with ammonites, goniatites and other fossils
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