Your ammonite probably is...

Dactylioceras

Dactylioceras was a small, typical ammonite of the Lower Jurassic. It was a slow swimmer that may have been gregarious. It is one of the most common ammonites. Its shell was slightly evolute, with distinct radial ribs curving around the rounded venter.

https://commons.wikimedia.org/wiki/File:Dactylioceras_semicelatum_-_Naturhistorisches_Museum,_Braunschweig,_Germany_-_DSC05126.JPG