Phylloceratidae is the predominant family of the Phylloceratina with some 15 or more genera found in rocks ranging from the Lower Jurassic to the Upper Cretaceous. Members of the Phylloceratidae are characterized by smooth, involute shells with very thin walls. Many are covered with fine growth lines but are usually without ribbing. Sutures are complex with the major and minor branches of the saddles with phylloid or spatulate endings. Treatise on Invertebrate Paleontology Part L Mollusca 4, Ammonoidea, 1957

Evolution and phylogeny

The Phylloceratidae are probably derived from the Late Triassic Discophyllitidae by increasing the sutural complexity and evolving involute coiling. The Discophyllitidae in turn have their origin in the

Ussuritidae Ussuritidae are ancestral, Triassic, Phylloceratina characterized by generally smooth, discoidal, evolute shells with rounded venters and little or no ornamentation and by sutures with primitive monophyllitic saddles with a single terminal branch ...

, also known as the Monophyllitidae. The Phylloceratidae gave rise at or near the beginning of the Jurassic to the ancestral Lytoceratina, the early Lower Jurassic Peluroacanthitidae and Ectocentridae. The Phyloceratidae also gave rise at or near the beginning of the Jurassic to the Psiloceratoidea which unites families of the Early Jurassic Ammonitina. Other Jurassic Ammonitina are derived from the Lytoceratina. Later, phylloceratids are said to have given rise to Cretaceous Ammonitina included in the

Desmoceratoidea Desmoceratoidea, formerly Desmocerataceae, is a superfamily of Cretaceous ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonit ...

Hoplitoidea Hoplitoidea, formerly Hoplitaceae, is a superfamily of mostly Upper Cretaceous ammonites comprising families united by a similar suture pattern with multiple similar elements that tend to decrease in size going toward the umbi ...

, and Acanthoceratoidea.

Sutural morphology

Sutures in the Phylloceratidae vary in complexity and are usually described on the basis of the saddles, which diverge to the front. Saddle endings may be double (diphyllic), triple (triphyllic), or quadruple (tetraphillic). Branching may be asymmetric. Intervening lobes are variably branched with thorn-like or spinose terminations as viewed in plan.

Subfamilies and genera

* Calliphylloceratinae Spath, 1927 **''

Calliphylloceras ''Calliphylloceras'' is an ammonite belonging to the Phylloceratidae. Species Species within this genus include: * ''Calliphylloceras alontinum'' (Gemmellaro, 1884) * ''Calliphylloceras bicicolae'' * ''Calliphylloceras capitanii'' * ''Calliphyllo ...

'' Spath, 1927 **'' Holcophylloceras'' Spath, 1927 **'' Ptychophylloceras'' Spath, 1927 **''

Sowerbyceras ''Sowerbyceras'' is a genus of ammonoid cephalopods belonging to the family Phylloceratidae. These nektonic carnivores lived during the Jurassic period, from Oxfordian to Kimmeridgian age. Description Shells of ''Sowerbyceras'' can reach a di ...

'' Parona & Bonarelli, 1895 * Phylloceratinae Zittel, 1884 **'' Calaiceras'' **'' Carinophylloceras'' Klinger et al., 1975 **'' Hantkeniceras'' **'' Hypophylloceras'' (Salfeld, 1924) **'' Partschiceras'' Fucini, 1920 **''

Phylloceras ''Phylloceras'' is an extinct genus of ammonoid cephalopods belonging to the family Phylloceratidae. These nektonic carnivores lived from Early Jurassic (Hettangian age) to Late Cretaceous (Maastrichtian age) (from 201.30 to 66.043 Ma). Descrip ...

'' Suess, 1865 **''

Phyllopachyceras ''Phyllopachyceras'' is an extinct genus of ammonoid cephalopods belonging to the family Phylloceratidae. These nektonic carnivores lived in the Cretaceous, from Hauterivian to Maastrichtian to age.Sepkoski, JacSepkoski's Online Genus Database � ...

'' Spath, 1925 **''

Zetoceras ''Zetoceras'' is an extinct ammonoid cephalopod genus from the suborder Phylloceratina that lived during the Early and Middle Jurassic in what is now Europe, and is included in the (family) Phylloceratidae. ''Zetoceras'' has a compressed involut ...

'' Kovacs, 1939 *'' incertae sedis'' **'' Bonarellia''

References

{{Taxonbar, from=Q7188670 Ammonitida families Early Jurassic first appearances Late Cretaceous extinctions