4.3" Dactylioceras Ammonite Cluster - Posidonia Shale, Germany
This is a cluster of Dactylioceras ammonites from the Posidonia Shale of Germany. They have been compressed and are preserved on a black slate in a partially pyritized state. Comes with an acrylic display stand.
Ammonites were predatory mollusks that resembled a squid with a shell. These cephalopods had eyes, tentacles, and spiral shells. They are more closely related to a living octopus, though the shells resemble that of a nautilus. Ammonites appeared in the fossil record about 240 million years ago and they barely survived several major extinction events. The last lineages disappeared 65 million years ago at the end of the Cretaceous.