Late Cretaceous Ammonite

Marine Fossil

Scientific Name: Ammonoidea

Ammonites are an extinct group of mollusk related to living octopus and squid. Complete specimens are often difficult to find, but experts can sometimes identify species with just a small fragment. Ammonites have distinct morphology that varies across species. Paleontologists use physical features such as shape, coil, and ornamentation to identify ammonites and date the stratigraphic layers in which they are found. The remains of over 200 ammonite species have been found on multiple continents. Finding examples of the same species in multiple formations, even if they are miles apart, allows us to correlate those deposits and give them the same time stamp.

3D Late Cretaceous Ammonite—Ammonoidea

Chaco Culture National Historical Park, New Mexico

Alternative Text for the 3D Model

A 3D model. This model shows a rock slab with a coiled fossil shell exposed on the surface. The model can be rotated and tilted using a computer interface.

Ammonites are an extinct group of mollusk related to living octopus and squid . Complete specimens are often difficult to find, but experts can sometimes identify species with just a small fragment. Ammonites have distinct morphology that varies across species. Paleontologists use physical features such as shape, coil, and ornamentation to identify ammonites and date the stratigraphic layers in which they are found. The remains of over 200 ammonite species have been found on multiple continents. Finding examples of the same species in multiple formations, even if they are miles apart, allows us to correlate those deposits and give them the same time stamp.

To learn more, visit - https://www.nps.gov/articles/series.htm?id=7B32EA8A-A130-11C3-E755871E8385F30E

Footnotes linked to the model:

The many chambers, or camerae, within ammonite shells are separated by dividing walls called septa, which are visible here. These chambers may have provided structural support to the shell and helped control buoyancy.

After this ammonite died, its soft, squid-like body quickly degraded, but its hard shell remained. Water flowed through the exposed chambers, preserving their shape by filling them with minerals.

Footnotes

The many chambers, or camerae, within ammonite shells are separated by dividing walls called septa, which are visible here. These chambers may have provided structural support to the shell and helped control buoyancy.

After this ammonite died, its soft, squid-like body quickly degraded, but its hard shell remained. Water flowed through the exposed chambers, preserving their shape by filling them with minerals.

Related Links

• NPS—Chaco Culture National Historical Park
• NPS—National Fossil Day
• NPS—Photogrammetry
• NPS—Fossils and Paleontology
• NPS—Geology

Part of a series of articles titled
Chaco Collections—Paleontology.

Next:
Mosasaur Jaw

Where this belongs

• Chaco Culture National Historical Park

Where this page came from

This page was imported from National Park Service. Produced by the U.S. National Park Service and, as a work of the United States government, in the public domain.

Nobody has written it yet — it is the source material at a new address, which is why search engines are asked to skip it and why no one earns from it. It is up for grabs: take it on, and it is yours to rewrite and to earn from.