Ammonites have actually been understood to humanity for countless years. They are the source of numerous stories and myths. The name of this spiral-shelled cephalopod comes from the Egyptian god Ammon. Ammon was imagined as a man with the horns of a ram extending from his head. The curled ammonite shells looked like the horns and were called Ammon's Stones or ammonites. Ammonites have actually been known to humanity for thousands of years. The curled ammonite shells looked like the horns and were called Ammon's Stones or ammonites.
Numerous cultures throughout history have associated unique powers to this fossil.
In ancient Greece, it was said that if you put an ammonite under your pillow it would cure insomnia and bring excellent dreams.
If you put a golden ammonite (pryritized) under your pillow you would have prophetic dreams, the Romans believed that.
A Brief History of Ammonites
Ammonites first appeared in the Devonian Period. Early curled types had easy septa with a single arc like the members of the class orthocerida. Ammonites of later periods established septa that had detailed folds called saddles and lobes. They also established fragile lacey patterns on the outer shell. These patterns in addition to the shape of the shell and the structure of the septa are how this cephalopod is classified. Ammonites such as Russian Speetoniceras are great addition to a fossil collection often on auction.
Given that all living cephalopods (nautilus, octopus, and squid) are predators, we can presume that ammonites were. The only living cephalopod with an external shell is the chambered nautilus. The siphuncle is a tube that connects all the chambers in the shell with the find living animal.
Ammonites have a broad variety of size. Early ammonites, up until the middle Jurassic, were smaller sized, normally less than 9 inches or 23 centimeters.
The tough shell of the ammonite was quickly fossilized. This, integrated with the sheer abundance of this group of cephalopods and its evolutionary duration through several geologic discover here periods, make it a good index fossil. Index fossils assist geologists and paleontologists to figure out the age of rock layers. This is called biostratigraphy. It works like this. If you discover an ammonite from a genus understood to be from the Triassic Period, then the rock layer it came from must be Triassic. To be a great index fossil:
It needs to have broad distribution.
There need to be a great deal of them.
It must come from a group that develops rapidly.
They need to be easy to recognize.
Ammonites please all of the above requirements easily.
Termination of The Ammonites
Completion of the Cretaceous Period was also completion of the ammonites. This was about 65 million years earlier. Dinosaurs and numerous other species of animals and plants died out at about this very same time. It is thought that a substantial meteor hitting earth caused these mass terminations.
The curled ammonite shells resembled the horns and were called Ammon's Stones or ammonites.
Ammonites of later periods established septa that had detailed folds called lobes and saddles. The tough shell of the ammonite was easily fossilized. If you find an ammonite from a genus understood to be from the Triassic Period, then the rock layer it came from must website here be Triassic. The end of the Cretaceous Period was likewise the end of the ammonites.