AMMONITE SHELL
There is something about ammonites that is aesthetically pleasing to humans. Could it be Phi, the Golden Number (= 1.61803….), which is universal in nature? Or could it perhaps be the wonder of the ammonite's Fibonacci spiral, which observed in galaxies, the arrangement of leaves around a stem, and the shape of ammonite and nautiloid shells?
The Fibonacci sequence is a list of numbers, starting with 1, in which every number is equal to the sum of the previous two. This sequence can be represented visually by drawing boxes. The first box should be 1+1, the second box 1+1, the third 2+2, the fourth 3+3, the fifth 5+5, the sixth 8+8, and so on with every box adjacent to the one drawn before it. When one draws a quarter of a circle in each box, it creates a spiral identical to the one in an Ammonites’ shell.
Or, is it the ammonite's shells, originally composed of aragonite (a carbonite mineral), which is unstable at standard temperature and pressure, and reverts to calcite millions of years. Whether it is the shape or the shell, or perhaps both, ammonite fossils possess an inherent beauty that is pleasing to the eyes.
Ammonite shells are a naturally occuring example of the Fibonacci sequence in a fossil.
Rainbow flashes kiss the outer shell of this ancient spiral–the colors of this Ammonite fossil are a result of prismatic layers of aragonite crystals.
AMMONITE FAST FACTS
1. Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells.
2. Ammonites had beak-like jaws inside a ring of tentacles that extended from their shells to snatch prey.
3. They ate small fish and crustaceans.
4. Ammonites constantly built new shell as they grew, but only lived in the outer chamber.
5. Some ammonites could grow as large as 3 feet (1 meter) across! Scientists suspect that creatures such as the giant mosasaur Tylosaurus preyed on them.
6. A group of ammonites was called a “school”, just like fish.
7. Ammonites scooted through the shallow seas by squirting jets of water from their bodies. A thin tube-like structure called a siphuncle reached into the ammonites inner chambers to pump and siphon air that helped them move through the water.
8. Female ammonites grew up to 400% larger than males. Could this have been to make room to lay eggs?
9. Ammonites first appeared about 240 million years ago!
10. They went extinct with the dinosaurs 65 million years ago. Scientists use ammonite shells to help date other fossils.
