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Erycitidae Temporal range: Early - Middle Jurassic | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Subclass: | † Ammonoidea |
Order: | † Ammonitida |
Superfamily: | † Hildoceratoidea |
Family: | † Erycitidae Spath, 1928 |
Genera | |
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Erycitidae is a family of Lower and Middle Jurassic ammonites included in the Hildoceratoidea. The hammatoceratid subfamily Erycitinae is equivalent. Genera include Erycites (type) and Abbasites .
Erycitids are generally evolute with all whorls showing and are strongly ribbed with ribs branching on the outer part of the flanks and crossing over the outer rim, or venter.
In older taxonomies, e.g. W.J. Arkell et al., 1964 and D.T. Donovan et al., 1981, the Hammatoceratidae, which then included erycitid genera, was part of the Hammatoceratoidea. More recently the Erycitidae was reassigned to the Hammatoceratoidea which also includes the Hammatoceratidae, Graphoceratidae and Sonniniidae removed from the Hildoceratoidea, left with only the Hildoceratidae and its included subfamilies.
Abbasites is an extinct genus of ammonites from the early Middle Jurassic epoch, included in the ammonitid family Erycitidae.
Uhligites is an oppeliid ammonite included in the subfamily Streblitinae that lived during the latest part of the Jurassic and earliest Cretaceous; from about 150 to 140 m.y.a.
Stephanoceratoidea, formerly Stephanocerataceae, is a superfamily of middle- upper Jurassic ammonoid cephalopods within the order Ammonitida containing diverse forms, generally with sharp ribbing and complex suture lines. Aptychi are believed to be mostly granular (Granulaptycus) or concentrically ribbed on the surface (Praestriaptychus)
Otoidtidae: stephanoceratoid ammonitina from the early Middle Jurassic that begin as cadicones but become more planualte with age; derived from the Hammitoceratidae (Hildoceratoidea), probably through Erycites by way of Abbasites.
Hildoceratoidea, formerly Hildoceratacaea, is a superfamily of compressed or planulate ammonites, some tending to develop acute outer rims; generally with arcuate or sigmoidal ribs. Aptichus were found in place are double-valved.
Eoderoceratoidea is a superfamily of true ammonites from the Lower Jurassic, comprising seven phylogenetically related families, characterized in general by having ribbed evolute shells that commonly bear spines or tubercles. Adult shell size ranges from 2 or 3 cm to giants reaching 50 cm in such genera as Apoderoceras, Epideroceras, and Liparoceras.
Eoderoceratidae is the ancestral and most primitive family of the Eoderoceratoidea; lower Jurassic ammonite cephalopods, characterized by evolute, commonly serpenticonic, shells that had long body chambers and would have had no stable floating position; and thus resemble contemporary Psiloceratoidea. Spines, or tubercles, are typically found in two rows on the inner and outer parts of the whorl sides, joined by radial ribs. These are often more developed on the inner and middle whorls, becoming less so or absent on the outer. Sutures are highly complex.
Coeloceratidae is a family of ammonites belonging to the Eoderoceratoidea that lived during the Early Jurassic. Shells are evolute, tending to be broadly discoidal with depressed whorls bearing primary and secondary ribs that branch from outer lateral tubercles. Most of the included species have coronate inner whorls and outer tubercles only. In general, Coeloceratids resemble the Middle Jurassic Stephanoceras. Once regarded as the subfamily Coeloceratinae in the Eoderoceratidae, these ammonites are now given familial rank.
Amaltheidae is a family of eoderoceratoidean ammonitids from the Lower Jurassic consisting of genera characterised by stigated discoidal oxycones—narrow involute shells with narrowly rounded to angular venters that bear a series of grooves, or ridges, along broad flanks, which according to the Treatise L, 1957, evolved into strongly ribbed planulates with quadrate whorls, typically with crenulated keels; involving all together four genera.
Liparoceratidae is a family of eoderoceratoidean ammonites from the Lower Jurassic that combines genera with a variety of forms including dimorphs that change from one form to another during ontogeny.
Berriasellinae is a subfamily of very late Jurassic and very early Cretaceous perisphinctoid ammonites in the family Neocomitidae. Berriasellinae comprises generally compressed, evolute genera, typically with furcated ribbing, and in some a smooth ventral band or groove. Berriasellinae are derived from the Ataxioceratidae and gave rise to the other Neocomitidae. The short lived Himalayitidae from the uppermost Jurassic have a similar appearance but differ in being generally broader and having sharper ribbing.
Oppeliidae are compressed to oxyconic, sculptured Haploceratoidea, either unkeeled, unicarinate, bicarinate, or tricarinate; with sutures in great variety, but ribbing usually more or less falcoid or falcate. The Oppeliidae is the principal family of the Haploceratoidea, with the longest duration, extending from the Middle Jurassic (Bajocian) to the Upper Cretaceous (Cenomanian) Their derivation is from the Hildoceratoidea.
Hildoceratidae is a family of ammonoid cephalopods from the Lower Jurassic, lower Pliensbachian to lower Bajocian substages, generally with strongly ribbed, involute shells. They are combined with the Hammatoceratidae, Graphoceratidae, and Sonniniidae to make up the Hildoceratoidea.
Perisphinctidae is a family of Middle and Upper Jurassic discoidal ammonites in the order Ammonitida. They have a shell morphology that is mostly evolute, typically with biplicate, simple, or triplicate ribbing. Large forms have simple apertures and smooth body chambers while small forms have lappets and ribbed body chambers.
Hammatoceratoidea, formerly Hammatocerataceae was a superfamily of middle Jurassic ammonites erected by Schindewolf in 1964 that combined the families Graphoceratidae, Hammatoceratidae, and Sonniniidae. The three families were previously included in the Hildoceratoidea, however subsequent classifications have moved the families back into Hildoceratoidea.
Sonniniidae is a diverse family of Middle Jurassic ammonites ranging from those with stout evolute shells to those whose shells are sharply rimmed, oxyconic. The keel, which runs along the middle of the venter, is typically hollow. Sutures vary from simple to complex. The aptychus is shiny with coarse folds (Cornaptychus).
The Ochetoceratinae is a subfamily within the Oppeliidae from the Upper Jurassic, shells of which are typically oxycones with a tricarinate venter and falcoid ribbing, commonly divided by a medain lateral groove or fillet. The median (middle) keel is the tallest.
Hammatoceratidae is a family of lower and middle Jurassic ammonites included in the superfamily Hildoceratoidea.
Hammatoceras is a genus of ammonites belonging to the family Hammatoceratidae which lived during the Toarcian stage of the Early/Lower Jurassic between about 184 and 175 million year ago.
Bredyia is a genus of ammonites from the lower part of the Middle Jurassic, found in Europe and North America.