The Medlicottiaceae is the second of the two superfamilies that make up the Prolecanitida

Prolecanitida

The Prolecanitida are extinct ammonoid cephalopods with discoidal to thinly lenticular shells with goniatitic or ceratitic sutures and which retained the simple retrochoanitic siphuncle with backward extending septal necks. As typical for ammonoids the siphuncle is along the ventral margin...

, the first being the Prolecanitaceae

Prolecanitaceae

Prolecanitaceae is a taxonomic superfamily of ammonites, fossil cephalopods. This is one of two superfamilies in the Prolecanitida. The other is the Medlicottiaceae....

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The Medlicottiaceae are recognized by their discoidal to thinly lenticular, and involute shells with small umbilici; flat, often grooved venters, and variably complex sutures. Medlicottiacean shells are often more ornamented and may sport ventrolateral nodes or ribs.

The Medlicottiaceae combines two related families, the ancestral Pronoritidae, descended from the Prolecanitidae in the Upper Mississippian and the derived Medlicottiadae which first appeared in the Lower Pennsylvanian. A third family, the Sageceratidae, considered to be derived from the Medlicottiadae, is included in the Ceratitida

Ceratitida

The Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post Triassic ammonites....

 in more recent classifications.

The Medlicottiaceae have become known by the alternative Medlicottiodea, following the recent ruling by the ICZN

International Commission on Zoological Nomenclature

The International Commission on Zoological Nomenclature is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 28 members from 20 countries, mainly practicing zoological taxonomists...

regarding superfamily endings. Medlicottiaceae nevertheless has a long standing in the literature with the taxonomic rank clear, without the need for explanation.