Liparoceratidae is a family of eoderoceratacean

Eoderocerataceae

Eoderocerataceae is a superfamily of true ammonites from the Lower Jurassic, comprising seven phylogenetically related families, characterized in general by having ribbed evolute shells that commonly bear spines or tubercles...

 ammonites from the Lower Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 that combines genera with a variety of forms including dimorphs that change from one form to another during ontogeny

Ontogeny

Ontogeny is the origin and the development of an organism – for example: from the fertilized egg to mature form. It covers in essence, the study of an organism's lifespan...

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Three genera and six subgenera are included in the Liparoceridae according to D.T. Donovan in Donovan et al. 1981; Liparoceras including L. (Liparoceras), L. (Becheiceras), and L. (Vicininodiceras); Aegoceras

Aegoceras

Aegoceras is an evolutely wound ammmonite, with wide spaced ribs, from the Early Jurassic included in the Liparoceratidae and superfamily Eoderoceratidae. Related genera are Leparoceras and Beaniceras.-References:*...

including A. (Aegoceras), A. (Beaniceras), and A. (Oistoceras); and Androgynoceras

Androgynoceras

Androgynoceras is an extinct genus of cephalopod belonging to the Ammonite subclass. The Green Ammonite Beds of the Dorset Coast are named after Androgynoceras lataecosta which has chambers filled with green calcite.- Species of Androgynoceras :...

. Arkell, et al. (1957) in the Treatise on Invertebrate Paleontology, Part L

Treatise on Invertebrate Paleontology

The Treatise on Invertebrate Paleontology published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and...

 list Liparoceras with Becheiceras and Vincininodiceras along with Parinodiceras separately as subgenera; Beaniceras, Metacymbites, Oistoceras, and Platynoticeras but leave out Aegoceras. Parinodiceras and its equivalent, Platynoticeras are removed (Donovan 1981) to the Polymorphitidae.
Metacymbites is a smooth dwarf and may form a dimorphic pair with Liparoceras.

The Liparoceratidae are thought to have evolved from the Eoderoceratidae

Eoderoceratidae

The Eoderoceratidae is the ancestral and most primitive family of the Eoderocerataceae; lower Jurassic ammonite cephalopods, characterized by evolute, commonly serpenticonic, shells that had long body chambers and would have had no stable floating position; and thus resemble contemporary...

 along with the Coeloceratidae

Coeloceratidae

Coeloceratidae is a family of ammonites belonging to the Eoderocerataceae] that lived during the Early Jurassic. Shells are evolute, tending to be broadly discoidal with depressed whorls bearing primary and secondary ribs that branch from outer lateral tubercles. Most of the included species have...

 and Polymorphidae

Polymorphidae

The thorny-headed worm family Polymorphidae contains endoparasites which as adults feed mainly in fish and aquatic birds. When this taxon was erected by Meyer in 1931, a subfamily Polymorphidae was established in it...

 close to the same time during the Sinemurian

Sinemurian

In the geologic timescale, the Sinemurian is an age or stage in the Early or Lower Jurassic epoch or series. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma...

 stage of the Early Jurassic, and in the following Pliensbachian

Pliensbachian

The Pliensbachian is an age of the geologic timescale or stage in the stratigraphic column. It is part of the Early or Lower Jurassic epoch or series and spans the time between 189.6 ± 1.5 Ma and 183 ± 1.5 Ma . The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.The...

 gave rise to the Amaltheidae

Amaltheidae

Amaltheidae is a family of eoderoceratacean ammonitids from the Lower Jurassic consisting of genera characterised by stigated discoidal oxycones—narrow involute shells with narrowly rounded to angular venters that bear a series of grooves, or ridges, along broad flanks, which according to the...

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