''Lissoceras'' is an involute, smooth or finely vetrolaterally ribbed,

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

with a blunt, un-keeled venter, included in the

Haploceratidae The Haploceratidae is the type family of the Haploceratoidea, a superfamily in the ammonitina; which according to Donovan ''et al.'' (1981) can be derived from the Taramelliceratinae, a subfamily of the Oppeliidae. Haploceratids, (Haploceratidae ...

, that lived from the Lower

Bajocian In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.3 Ma to around 168.3 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age. Stratig ...

- Middle Oxfordian (Middle to Upper Jurassic) in what is now Europe, south Asia, and southern Alaska. ''Lissoceratoides'', once considered to be a subgenus of ''Lissoceras'', is indistinguishable morphologically from it.

References

;Notes ;Bibliography *Arkell ''et al.'', 1957 Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology Part L. Geol Society of America and Univ Kansas Press R.C Moore (ed) 1957 *D.T Donavan, J.H. Callomon, and M.K Howarth. 1981. Classification of the Jurassic Ammonitina. In ''The Ammonoidea''. M.R. House and J.R. Senior, eds. Systematics Assoc. Pub Academic Press. Haploceratoidea Ammonitida genera Middle Jurassic ammonites Late Jurassic ammonites Middle Jurassic ammonites of Europe Late Jurassic ammonites of Europe Jurassic ammonites of North America Middle Jurassic North America Late Jurassic North America Bajocian first appearances Late Jurassic extinctions {{Jurassic-animal-stub