Phricodoceratidae
Phricodoceratidae is a family in the Eoderoceratoidea, aberrant ammonites from the Lower Jurassic characterized by a large adult size and a marked change of shell form and ornament with growth. Shells are stoutly ribbed, early growth stage is round-whorled with spines, followed by a high-whorled late growth stage with smooth, modified ribbing.
Three genera are currently placed in the Phricodoceratidae: Phricodoceras, Epideroceras, and Pseuduptonia.
