The Simoceratinae is a subfamily in the

Aspidoceratidae The Aspidoceratidae comprise a family of middle and upper Jurassic ammonites that make up part of the superfamily Perisphinctoidea, characterized by evolute shells, commonly stocky, that tend to develop tubercles. The Aspidoceratidae are thought ...

, a family of ammonites in the

Perisphinctaceae Perisphinctoidea, formerly Perisphinctaceae, is a superfamily of Middle Jurassic (Bajocian) to Lower Cretaceous (Barremian) ammonites, commonly with evolute shells with strong ribbing that typically divides about mid flank before crossing the ven ...

, that lived during most of the Late Jurassic, especially in the Pacific and Tethyan realms. Early genera more closely resemble Perisphictidae and have constricted apertures. Later, more aberrant forms are unconstricted and develop grooved or concave venters.

''References''

* Arkell, et al., 1957. Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L. (Ammonoidea). Geol Soc of America and Univ Kansas Press. Jurassic ammonites Aspidoceratidae {{Ammonitina-stub