''Reynesoceras'' is genus of

ammonites 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) ...

that lived during the upper Pliensbachian stage of early Jurassic. It has evolved from ''

Prodactylioceras ''Prodactylioceras'' is genus of ammonite that lived during the Pliensbachian stage of early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the e ...

'', or ''

Cetonoceras ''Cetonoceras'' is genus of ammonite that lived during the upper Pliensbachian stage of early Jurassic. Fossils of this genus were found in Italy, France, Spain, Portugal, Hungary and Austria.Géczy, B., Meister, C. 1998. Les ammonites du Domé ...

''. '' Dactylioceras (Eodactylites)'' has probably evolved from this genus. ''Aveyroniceras'' is a name for macroconchs of this genus. Their fossils were found in Europe, northern Africa, Asia, North America and South America.Kovács, Z. (2014). Toarcian Dactylioceratidae (Ammonitina) from the Gerecse Mts (Hungary). Hantkeniana, 9, 45-77.

Description

Ammonites of this genus had shells with depressed whorl section and single, coarse ribs. Ribs are crossing venter, but there is no bifurcation, which is often present on other genera belonging to ''

Dactylioceratidae The family Dactylioceratidae comprises Early Jurassic ammonite genera with ribbed and commonly tuberculate shells that resembled later Middle Jurassic stephanoceratids and Upper Jurassic perisphinctids. Shells may be either evolute or involu ...

''. Also, there are no tubercules, which is a thing that differs them from ''

Tokurites ''Tokurites'' is a monospecific genus of ammonite that lived during the Toarcian stage of early Jurassic, ammonite zone of Zugodactylites braunianus. Its shell has ribs, which cross the ventral part of the shell creating pricky tubercules there. ...

''.Repin Yu.S. Ammonitovaya shkala nizhney yury Severo-Vostoka Azii ower Jurassic ammonite geologic time scale of Northeast Asia Neftegazovaya Geologiya. Teoriya I Praktika, 2016, vol. 11, no. 4, available at: http://www.ngtp.ru/rub/2/47_2016.pdf

Distribution

British Columbia, Chile, Hungary, Italy and Morocco Paleobiology Database - Reynesoceras
2017-10-16.

References

Dactylioceratidae Ammonites of Africa Ammonites of Asia Ammonites of North America Ammonites of South America Ammonitida genera Jurassic ammonites {{Ammonitina-stub