''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
The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-J ...
. 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''. ''
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''.
[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](_blank)
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