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ammonite: Per Wikipedia the ammonites went extinct with Dinosaurs 65 million years ago. Ammonites survived until the end of the Cretaceous period in a sea that covered what is now Alberta. Canada and Montana, USA. These ammonites were transformed into the rare gem known as Ammolite.
Spirals are a beautiful shape. They have marvelous curves and convey energy and motion. Not only that, they are a truly efficient form used in nature, and we see them so many places in our every day lives!
Ammonite suture patterns - these dendritic patterns are the line of intersection between the ammonite's shell and its septa, which are the walls it built as it extended its shell. More information: n-e-r-v-o-u-s.com/blog/?p=1176
Ammonites at the Smithsonian. Originating from within the bactritoid nautiloids, the ammonoid cephalopods first appeared in the Devonian (circa 400 million years ago) and became extinct at the close of the Cretaceous (65.5 Ma) along with the dinosaurs.
Ammonites are an extinct group of marine invertebrate animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs are more closely related to living coleoids than they are to shelled nautiloids such as the living Nautilus species.