Perisphinctoidea, formerly Perisphinctaceae, is a superfamily of Middle
Jurassic
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...
(Bajocian) to
Lower Cretaceous
Lower may refer to:
*Lower (surname)
*Lower Township, New Jersey
*Lower Receiver (firearms)
*Lower Wick
Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eig ...
(Barremian)
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 cuttl ...
, commonly with evolute shells with strong ribbing that typically divides about mid flank before crossing the venter.
Classification
Some 16 families have been recognized in the Perisphinctoidea. The following is based on Donovan ''et al.'' 1981Donovan, Callomon and Howarth 1981 Classification of the Jurassic Ammonitina; Systematics Association. with modification from the Treatise on Invertebrate Paleontology, Part L (1957)
* Perisphinctidae: Middle and Upper Jurassic root stock, derived from the Stephanoceratidae
(Middle Jurassic direct derivatives of the Perisphinctidae)
* Morphiceratidae
* Tulitidae
* Reineckeiidae
*
Pachyceratidae
Pachyceratidae is a family of Perisphinctoidean ammonites from the upper Middle - and lower Upper Jurassic. Genera within the Pachyceratidae have shells that are in general moderately involte but with most of the inner whorls exposed; whorl sec ...
* Aspidoceratidae
(early Upper Jurassic (Oxfordian) derivatives of Perisphinctidae)
*
Aulacostephanidae
Aulacostephanidae is an extinct ammonoid cephalopod family belonging to the superfamily Perisphinctoidea. These fast-moving nektonic carnivores lived during the Upper Jurassic period, from the Oxfordian to Tithonian
In the geological timesca ...
*
Ataxioceratidae
Ataxioceratidae is an extinct Ammonite cephalopod family included in the superfamily Perisphinctoidea. These fast-moving nektonic carnivores lived during the Jurassic and Cretaceous periods.
Genera
*'' Catutosphinctes''
*'' Choicensisphinctes'' ...
(mid Upper Jurassic (Kimmeridgian) derivatives of the Ataxioceratidae)
* Dorsoplanitidae
* Virgatitidae
(late Upper Jurassic (Tithonian) derivatives of Perisphinctidae)
* Simoceratidae
*
Himalayitidae
Himalayitidae is an extinct family of ammonites in the superfamily Perisphinctoidea. The family existed from the Tithonian of the Jurassic to the Berriasian of the Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 ...
*
Olcostephanidae
Olcostephanidae is an extinct ammonoid cephalopod family belonging to the superfamily Perisphinctoidea. These fast-moving nektonic carnivores lived from the Jurassic to the Cretaceous period.
Genera
*'' Bihenduloceras''
*'' Olcostephanus'' Neuma ...
*
Holcodiscidae
Holcodiscidae is an ammonite family placed in the superfamily Desmoceratoidea. Berriasellidae (derived from Ataxioceratidae)(now considered a subfamily of Neocomitidae)
* PolytichitidaeCraspeditidae.html" ;"title="Craspeditidae.html" ;"title="Craspeditidae">Craspeditidae">Craspeditidae.html" ;"title="Craspeditidae">Craspeditidae(derived from Dorsoplanitidae)
*Neocomitidae (derived from Berriasellidae)(now placed in the superfamily Endemoceratoidea)
*Oosterellidae (Hauterivian derivative of the Neocomitidae)