A beautiful ammonite
Updated: Jul 21, 2020
Sometimes I find things in nature on my own, sometimes I purchase things. This I purchased at a fossil and mineral show in New York City. I believe it's important to support such shows to keep them going.
This is a nice ammonite [Perisphinctes], I guess some 165 million year-old I suspect this one is from the Jurassic period--it was collected in Madagascar. Perisphinctes is an extinct genus of ammonite cephalopods.
I've brought this little guy to some small classes I used to teach. It is about 9 inches (22.8 cm) across. What's amazing is that this just to swim in the ancient seas which covered parts of the planet, including what is today the United States.
These can be found around the world, some smaller than a sugar cube, and some as large as a car.