What is "creniceras"

Creniceras is a rather small Upper Jurassic ammonite with a shell in the range of about 1.6 cm in diameter,(about 1/2 in). The shell of Creniceras is eccentrically coiled, compressed, and generally smooth, except for a median row of cockscomb serrations on the body chamber and the possibility of blunt ribbing on the sides.

Creniceras, named by Munier-Chalmas in 1892, is included in the oppeliid subfamily Teramelliceratinae, and has been found in Upper Jurassic (Oxfordian age) sediments in Europe and Syria.