Perisphinctoidea Explained

Perisphinctoidea, formerly Perisphinctaceae, is a superfamily of Middle Jurassic (Bajocian) to Lower Cretaceous (Barremian) ammonites, commonly with evolute shells with strong ribbing that typically divides about mid flank before crossing the venter.^[1]

Classification

Some 16 families have been recognized in the Perisphinctoidea. The following is based on Donovan et al. 1981^[2] with modification from the Treatise on Invertebrate Paleontology, Part L (1957)^[1]

Perisphinctidae

Middle and Upper Jurassic root stock, derived from the Stephanoceratidae

(Middle Jurassic direct derivatives of the Perisphinctidae)

Morphiceratidae
Tulitidae
Reineckeiidae
Pachyceratidae
Aspidoceratidae

(early Upper Jurassic (Oxfordian) derivatives of Perisphinctidae)

(mid Upper Jurassic (Kimmeridgian) derivatives of the Ataxioceratidae)

Dorsoplanitidae
Virgatitidae

(late Upper Jurassic (Tithonian) derivatives of Perisphinctidae)

Simoceratidae
Himalayitidae
Olcostephanidae
Holcodiscidae (indirect, from Olcostaphanidae)(now placed in the suberfamily Desmoceratoidea)

(Lower Cretaceous Perisphinctoidea (Berriasan - Hauterivien)

Berriasellidae (derived from Ataxioceratidae)(now considered a subfamily of Neocomitidae)
Polytichitidae [=[[Craspeditidae]]] (derived from Dorsoplanitidae)
Neocomitidae (derived from Berriasellidae)(now placed in the superfamily Endemoceratoidea)
Oosterellidae (Hauterivian derivative of the Neocomitidae)

Notes and References

Book: W.J. . Arkell . B. . Kummel . C.W. . Wright . Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Mesozoic Ammonoidea . Geological Society of America and University of Kansas Press . Lawrence, Kansas. 1957.
Donovan, Callomon and Howarth 1981 Classification of the Jurassic Ammonitina; Systematics Association. Web site: Archived copy . 2010-11-20 . dead . https://web.archive.org/web/20110716054651/http://rogov.zwz.ru/Donovan,%20Callomon,%201981_J%20Ammon.PDF . 2011-07-16 .