9.75" Douvilleiceras (Tractor) Ammonite - Massive 17 lbs!

This is a huge 9.75" wide Douvilleiceras ammonite from the Upper Cretaceous of Madagascar. This genus of ammonites has earned the local name "Tractor Ammonites", due to their distinctively bumpy surface and pronounced ridges making them resemble a tractor tire. This particular example has been nicely prepared to remove the hard rock and expose the shell.

About Ammonites

Ammonites were ancient marine cephalopods, similar to today's squids and octopuses, but with a defining feature: their distinctive, tightly coiled spiral shells. These shells, resembling those of modern nautiluses, served as both a protective home and a buoyancy aid, allowing ammonites to navigate the prehistoric seas with ease. First emerging around 240 million years ago in the Triassic Period, ammonites thrived for over 175 million years, adapting through numerous forms and sizes. As predatory creatures, they likely fed on smaller marine organisms, using their tentacles to capture prey. However, their long reign came to an end 65 million years ago at the close of the Cretaceous, coinciding with the mass extinction event that also eliminated the dinosaurs.

What an ammonite would have looked like while alive.
What an ammonite would have looked like while alive.
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DETAILS
SPECIES
Douvilleiceras mammilatum
LOCATION
Mahajanga Province, Madagascar
SIZE
9.75" wide, up to 5" thick, over 17 pounds
ITEM
#81862
GUARANTEE
We guarantee the authenticity of all of our specimens.