Polyptychoceras is a heteromorph ammonite, meaning that its shell does not curl up into the tight spiral shape which shells of ammonites from the subclass Ammonoidea typically do.

Polyptychoceras shells have an abrupt weight increase after formation of the initial shaft, which represents the shell's automatic balance condition.
This would have caused the shell to topple over if on land.
The soft body of the animal would have to have been large, in order to keep the falling shaft off of the ground.
The body would not have been resistant to the pressing shell.

Although the shafts in the fossils of the shells are usually parallel to each other, small aberrations during each growth stage often caused abrupt constrictions in the shape of the shell.
Polyptychoceras is a heteromorph ammonite, meaning that its shell does not curl up into the tight spiral shape which shells of ammonites from the subclass Ammonoidea typically do.
Polyptychoceras shells have an abrupt weight increase after formation of the initial shaft, which represents the shell's automatic balance condition. This would have caused the shell to topple over if on land. The soft body of the animal would have to have been large, in order to keep the falling shaft off of the ground. The body would not have been resistant to the pressing shell.
Although the shafts in the fossils of the shells are usually parallel to each other, small aberrations during each growth stage often caused abrupt constrictions in the shape of the shell.
Polyptychoceras