In collaboration with with Frédéric Diebold - Fossils Expert
It wasn’t just the dinosaurs which became extinct 65 million years ago. Ammonites, a pre-historic type of marine mollusc, had a vast existence of more than 300 million years. They from the Devonian period to the end of the Cretaceous system, when they became extinct around the same time as the dinosaurs. Now their history is stamped all over the earth in the form of some fascinating fossils casting the shells that these once squid-like creatures left behind. But what is it that’s so interesting about these ammonite fossils and why are they worth studying? Let’s find out!
Evolving and Adapting
During their existence, ammonites evolved into tens of thousands of species, which adapted to a broad range of marine environments, from shallow shelves to deeper oceanic conditions. In fact, ammonites were so successful at adaptation that modern palaeontologists use ammonites as index species to subdivide geological times. Not only was their ability to adapt so successful, but the speed in which they evolved was incredible. It took less than one million years for one species of ammonite to vanish while new ones appeared - and in geological terms, that’s pretty fast!
How to Spot an Ammonite
Ammonites are instantly recognisable by their spiraled coiling and peculiar ornamentation composed of ribs and tubercles - ridges which encircle the coils. Mostly all ammonite families had this similar coil shape, although there were also some non-spiraled forms called heteromorphs. Their spiraled appearance inspired the organism’s name: the word ‘ammonite’ is derived from 'ammonis cornua', meaning 'horns of Ammon'. The term was coined by Pliny the Elder in 79 AD, because of the way the ammonite coiling resembles the Egyptian god Ammon, often depicted with ram’s horns. It is this beautiful shaping which makes ammonite fossils so appealing to collectors.
Ammonites Hidden in Legend
During the Middle Ages, it was a popular belief in Yorkshire, the United Kingdom, that the swirling shapes of ammonite fossils were in fact snakes that had been turned to stone by Saint Hilda. In order to make this legend seem more credible (and in order to hide the fact that these supposed ‘snakes’ had no head or skull,) craftsmen used to sculpt a snake head on the body chamber of the ammonites and then sell them to pilgrims as ‘proof’ of the miracle. Such legends still exist today in the Himalayas, where ammonites are called shaligrama. Hindu populations living along the Gandaki and Spiti valleys of India and Nepal use shaligrama as a non-anthropomorphic symbol of Vishnu, one of the main deities of Hinduism.
Ammonites Today
Nowadays, ammonite fossils are often found in most sedimentary rocks from the Devonian to Cretaceous periods, and outcrops of these rocks can be found in mountains and sedimentary basins. Such outcrops include quarries, sea coasts, river shores, deserts, canyons and even underground cellars. And not forgetting, of course, ammonite fossils are available here at our Fossils auction and Premium-Grade Fossils auction!
You can discover a huge variety of incredible paleontological finds from ammonites to dinosaur eggs at our Fossils auction and Premium-Grade Fossils auction. These auctions are also great platforms for easily and quickly selling your fossils online. All you need to do is register as a seller to begin with, and then you can submit your items for auction.