Description

Ptychoceras sp.
Heteromorph
Lower Cretaceous (Aptian)
Samurskaya layer
Kurgips river, Apsheron, Krasnodar region, Russia

21mm heteromorph on 62mm slab.

Ammonite.  Cephalopod.

Heteromorph ammonites are the ones with shells making hairpin turns or seemingly melted into unnatural shapes.  Complete ones are hard-to-find and expensive but you can start slow and pick up a piece of one here.

Ptychoceras is known from the Early Cretaceous of North America and Russia.