The Ammonites (such as Speetoniceras from Russia) - (Reference|Index} Fossils



Ammonites have been known to mankind for countless years. They are the source of lots of stories and myths. The name of this spiral-shelled cephalopod comes from the Egyptian god Ammon. Ammon was envisioned as a man with the horns of a ram protruding from his head. The curled ammonite shells looked like the horns and were called Ammon's Stones or ammonites. Ammonites have been understood to humanity for thousands of years. The curled ammonite shells looked like the horns and were called Ammon's Stones or ammonites.

Ammonite Myths
Many cultures throughout history have attributed unique powers to this fossil.

In ancient Greece, it was stated that if you put an ammonite under your pillow it would treat sleeping disorders and bring good 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 initially appeared in the Devonian Period. Early curled species had simple septa with a single arc like the members of the class orthocerida. Ammonites of later durations established septa that had detailed folds called lobes and saddles. They also established fragile lacey patterns on the external shell. These patterns in addition to the shape of the shell and the structure of the septa are how this cephalopod is categorized. Ammonites such as Russian Speetoniceras are highly collectible fossils often on auction.

Considering that all living cephalopods (octopus, nautilus, and squid) are predators, we can assume that ammonites were. The only living cephalopod with an external shell is the chambered nautilus. The siphuncle is a tube that links all the chambers in the shell with the my company living animal.

Ammonite Size
Ammonites have a large variety of look at this website size. Early ammonites, up until the middle Jurassic, were smaller, typically less than 9 inches or 23 centimeters.

Biostratigraphy
The hard shell of the ammonite was quickly fossilized. This, combined with the sheer abundance of this group of cephalopods and its evolutionary duration through a number of geologic durations, make it a good index fossil. If you find an ammonite from a genus known to be from the here Triassic Period, then the rock layer it came from must be Triassic.

It must have wide distribution.

There should be a great deal of them.

It needs to belong to a group that evolves rapidly.

They must be simple to acknowledge.

Ammonites please all of the above criteria easily.

Extinction of The Ammonites
The end of the Cretaceous Period was also the end of the ammonites. Dinosaurs and numerous other species of animals and plants died out at about this same time.

The curled ammonite shells looked like the horns and were called Ammon's Stones or ammonites.

Ammonites of later durations developed septa that had actually detailed folds called lobes and saddles. The difficult shell of the ammonite was easily fossilized. If you discover an ammonite from a genus understood to be from the Triassic Period, then the rock layer it came from should be Triassic. The end of the Cretaceous Period was also the end of the ammonites.

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