Description
Here is a unique look at the inside of a Cephalopod that was infilled by calcite crystals.
Cystoid means “sac-like” referring to the portion of the creature called a theca. The theca is the main body and sits atop a column of round disk-shaped segments. A theca is comprised of a generally oval shaped body made up of geometric or plates. It contains all the internal organs as well as the mouth and anus.
This Crystal Fossil Cephalopod does not look like much from the outside. But inside it has beautiful calcite crystals. Cephalopods are related to the modern day octopus.
Then they had hard external shells either coiled or straight. Because these creatures had tentacles like the modern day octopus they were considered ocean going predators. Because the creature was soft bodied only the hard external shell remains.
This Fossil Crystal Cephalopod is quite unique. These Cephalopod fossils are easily recognizable because of their shell. Many had curved or coiled shells but some had long straight shells. In various parts of the world they can be found as large as several feet in diameter. And they can be found is shale concretions as in the ones found along the shores in England.
Cephalopod in Greek means head, foot. They have distinct sections within the body of the shell. The divisions that are clearly visible in polished varieties are called sutures.
