The Ammonites (Speetoniceras versicolor) - (Reference|Index} Fossils



Ammonites have actually been known to mankind for thousands of years. They are the source of many stories and myths. The name of this spiral-shelled cephalopod originates from the Egyptian god Ammon. Ammon was pictured 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 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 associated special powers to this fossil.

In ancient Greece, it was said that if you put an ammonite under your pillow it would treat sleeping disorders and bring great 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. Ammonites of later periods established septa that had intricate folds called saddles and lobes. Ammonites such as Speetoniceras from Russia are great addition to a fossil collection often on auction.

Because all living cephalopods (squid, nautilus, and octopus) are predators, we can assume that ammonites were also. The only living cephalopod with an external shell is the chambered nautilus. It can swim and manage its depth. It does this using the siphuncle. The siphuncle is a tube that connects all the chambers see this site in the shell with the living animal. The nautilus can deduct or add gas in these chambers to control buoyancy.

Ammonite Size
Ammonites have a large range of size. Specimens have actually been discovered ranging from less than a here centimeter to 2 meters in diameter. Early ammonites, till the middle Jurassic, were smaller sized, usually less than 9 inches or 23 centimeters. During the upper Jurassic and lower Cretaceous larger varieties can be found. Titanites found in the south of England can be over 50 centimeters, 2 feet in diameter.

Biostratigraphy
The hard 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 durations, make it a great index fossil. If you find an ammonite from a genus known to be from the Triassic Period, then the rock layer it came from need to be Triassic.

It needs to have broad distribution.

There need to be a great deal of them.

It should belong to a group that progresses quickly.

They must be simple to acknowledge.

Ammonites please all the above requirements easily.

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

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

Ammonites of later periods established septa that had intricate folds called saddles and lobes. The hard shell of the ammonite was quickly fossilized. If you discover an ammonite from a genus known to be from the Triassic Period, then the rock layer it came from need to be Triassic. The end of the Cretaceous Period was also the end of the ammonites.

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