| Ancyloceras, Ammonites, Deshayesites, Textularia, Exogyra|
Ancyloceras matheronianum is an extinct species of heteromorph ammonite cephalopod belonging to the family Ancyloceratidae. It is the type species of the genus.
These fast-moving nektonic carnivores lived during the Cretaceous period, Lower Aptian age (from 125.45 to 122.46 Ma). Fossils of this species are found in the marine strata of France, Russia and Morocco.
Ancyloceras matheronianum Wikipedia
Ancyloceras matheronianum ammonites have quite large shells, reaching a length of about 30–40 centimetres (12–16 in). They are heteromorph shaped, with a partly uncoiled shell and the aperture directed toward the coiled part.