Otoitidae
Encyclopedia
Otoidtidae: stephanoceratacean
ammonitina
from the early Middle Jurassic
that begin as cadicones but become more planualte with age; derived from the Hammitoceratidae (Hildocerataceae), probably through Erycites by way of Abbasites
.
Shells begin barrel shaped with depressed whorls, broad outer rims, and deep, crater-like umbilici—cadiconic—but become compressed, with the out rims becoming bluntly rounded—planulate. Ribbing is common; may be heavy and tuberculate on the umbilical shoulders and may divide along the flanks before crossing the outer rim -the venter- uninterrupted.
The Otoitidae is the ancestral family of the Stephanocerataceae and is known only from a relatively short interval of time within the Bajocian
stage at the beginning the Middle Jurassic and begins with Docidoceras
. They gave rise, probably through varieties of Docidoceras to the Stephanoceratidae
and Sphaeroceratidae, which in tern gave rise to the different phylogenetic branches within the Stephacerataceae.
Stephanocerataceae
Stephanocerataceae is a superfamily of middle Jurassic ammonoid cephalopods within the order Ammonitida containing diverse forms, generally with sharp ribbing and complex suture lines...
ammonitina
Ammonitina
The Ammonitina comprises a diverse suborder of ammonoid cephalopods that lived during the Jurassic and Cretaceous periods of the Mesozoic Era. They are excellent index fossils, and it is often possible to link the rock layer in which they are found to specific geological time periods.The shells of...
from the early Middle Jurassic
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....
that begin as cadicones but become more planualte with age; derived from the Hammitoceratidae (Hildocerataceae), probably through Erycites by way of Abbasites
Abbasites
Abbasites is an extinct ammonite genus from the early Middle Jurassic included in the ammonitid family Erycitidae.-Description:Abbasites is small and subglobular with ribbing that divides high on its sides and which has an interruption on the venter that replaces the keel, generally characteristic...
.
Shells begin barrel shaped with depressed whorls, broad outer rims, and deep, crater-like umbilici—cadiconic—but become compressed, with the out rims becoming bluntly rounded—planulate. Ribbing is common; may be heavy and tuberculate on the umbilical shoulders and may divide along the flanks before crossing the outer rim -the venter- uninterrupted.
The Otoitidae is the ancestral family of the Stephanocerataceae and is known only from a relatively short interval of time within the Bajocian
Bajocian
In the geologic timescale, the Bajocian is an age or stage in the Middle Jurassic. It lasted from approximately 171.6 Ma to around 167.7 Ma . The Bajocian age succeeds the Aalenian age and precedes the Bathonian age....
stage at the beginning the Middle Jurassic and begins with Docidoceras
Docidoceras
Docidoceras is an extinct ammonite genus from the order Ammonitida that lived during the Middle Jurassic in what is now Europe, North Africa, and Oregon. Docidoceras is included in the family Otoitidae which makes up part of the ammonite superfamily Stephanocerataceae.Docidoceras has a broad,finely...
. They gave rise, probably through varieties of Docidoceras to the Stephanoceratidae
Stephanoceratidae
Sephanoceratidae is a family of planulate and coronate ammonites within the Stephanocerataceae. Shells are evolute so that all whorls are exposed and have strong ribbing that bifurcates, that is splits in two, on the flanks. Many have tubercles at the point of bifurcation...
and Sphaeroceratidae, which in tern gave rise to the different phylogenetic branches within the Stephacerataceae.