''Quenstedtoceras'' is a genus of

ammonoid 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) ...

cephalopods that lived during the latter part of the Jurassic period in what is now France, Poland, Germany, and the United Kingdom.

Morphologic description

The shell of ''Quenstedtoceras'' is typically evolute and strongly ribbed, with all whorls visible. Widths vary according to the species from rather narrow to somewhat broad, as does ribbing. Ribs commonly start at the umbilical shoulder and extend laterally to about mid flank where they divide and curve forward toward the outer rim, or venter, and meet at a keel. Shells are of moderate size, commonly reaching diameters of about 6 cm (2.4 in).

Taxonomy and phylogeny

''Quenstedtoceras'', included in the superfamily Stephanocerataceae, now revised to Stephanoceratoidea, is first of the subfamily Cardioceratinae, derived from ''

Cadoceras ''Cadoceras'' is an extinct ammonite genus belonging to the Cardioceratidae that lived during the Jurassic period from the late Bajocian to the early Callovian In the geologic timescale, the Callovian is an age and stage in the Middle Jurassi ...

'' or related genus is the mid or late

Callovian In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago) and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the ...

and gave rise at the end of its range in the early Oxfordian to '' Cardioceras''.Quenstedtoceras
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References

Jurassic ammonites Ammonites of Europe Ammonitida genera Stephanoceratoidea {{ammonitina-stub