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Phylloceratidae
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, 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 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylloceratina
The Phyllocertina comprise a suborder of ammonoid cephalopods, belonging to the Ammonitida, whose range extends from the Lower Triassic to the Upper Cretaceous. Shells of the Phylloceratina are generally smooth with small to large umbilici and complex sutures with leaf-like phylloid saddle endings and lobes with thorn-like projections.Treatise on Invertebrate Paleontology Part L Mollusca 4, Ammonoidea, 1957 Phylogeny The Phylloceratina are most likely derived from the Ceratitid Deineroceratidae, which is thought to have given rise early in the Triassic to the Ussuritidae. The Ussuritidae is the ancestral family of the Phylloceratina. The Ussuritidae extend through the Upper Triassic but not into the Jurassic, and gave rise to the Upper Triassic Discophyllitidae. The Discophyllitidae is the probable source for the L Jurassic - U Cretaceous Phylloceratidae and possibly for the L Jurassic Juraphyllitidae. The Phylloceratina gave rise early in the Jurassic through the Phylloce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calliphylloceras
''Calliphylloceras'' is an ammonite belonging to the Phylloceratidae. Species Species within this genus include: * ''Calliphylloceras alontinum'' (Gemmellaro, 1884) * ''Calliphylloceras bicicolae'' * ''Calliphylloceras capitanii'' * ''Calliphylloceras demidoffi'' (Rousseau, 1842) * ''Calliphylloceras disputabile'' (type) Spath, 1927 * ''Calliphylloceras freibrocki'' Imlay, 1953 * ''Calliphylloceras kochi'' (Oppel, 1865) * ''Calliphylloceras nilssoni'' * ''Calliphylloceras nizinanum'' * ''Calliphylloceras propinquum'' * ''Calliphylloceras seroplicatum'' * ''Calliphylloceras spadae'' * ''Calliphylloceras supraliasicum'' The holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ... of ''C disputabile'', the type species, named by Spath in 1927, which came from the Middle Jurassic of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 diameter of about . Form is evolute, smooth, moderately thick, with rather flattened flanks. Evolution of the genus ''Sowerbyceras'' ''Sowerbyceras'' from the Kimmeridgian of Southern Alps (Northern Italy) show that the evolution of the Genus is strongly affected by fluctuations in sea level. In Southern Alps extinction and phyletic changes occur in transgressive phases instead of in regressive phases. Also the maxima and minima of intraspecific variability are the opposite to those of the epicontinental environment. During times of high sea-level (transgressive phases = slight bottom currents) Sowerbyceras faunas decreased in numbers, and were smaller, with a lower thickness ratio Wb/D (whorl breadth/Diameter) and a more evolute conch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 – Cephalopoda/ref> Species * ''Phyllopachyceras chitianum'' Imlay, 1960 * ''Phyllopachyceras infundibulum'' d'Orbigny, 1841 * ''Phyllopachyceras reymenti'' Riccardi, 2018 * ''Phyllopachyceras trinitense'' Anderson, 1938 * ''Phyllopachyceras umpuanum'' Anderson, 1938 Description Shells of ''Phyllopachyceras'' can reach a diameter of about . On the external surface ribs are alternately short and long and sutures show a high complexity, with saddle endings perfectly quadruple (tetraphillic). The section of the shell is quite thick. Distribution Fossils of species within this genus have been found in the Cretaceous of Antarctica, Argentina, Austria, China, France, Hungary, Italy, Japan, Madagascar, New Zealand, Poland, Russia, Spain, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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). Description Shells of ''Phylloceras'' can reach a diameter of about , with a maximum of about . These primitive ammonite 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 cuttlefish) ...s had an involute, laterally flattened shell with a regular shell opening. They were almost smooth and the ornamentation was virtually absent or, at most, represented by simple growth lines barely visible. The striking sinuous suture lines were characteristic of this genus. They are reminiscent, in some ways, of the leaves of plants (hence the name ''Phylloceras'', which means " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 involute shell with a very small umbilicus. The suture is phylloid, as for the suborder, with tall primary sutural elements. Saddles commonly have tetraphyllic endings. ''Zetoceras'' is considered by some (Wright ''et al'', 1996) to be a subgenus of ''Phylloceras''. The two are very similar except that the saddle endings in ''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 ...'' split in three rather than in four as in ''Zetoceras''. References * Wright, Calloman, and Howarth. 1996; Cretaceous Ammonoidea. Treatise on Invertebrate Pal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discophyllitidae
Discophyllitidae are discoidal, generally evolute Phylloceratina from the Upper Triassic, derived from the Ussuritidae, in which the principal saddles of the suture have bifurcated or trifurcated endings, described as being di- or triphyllic. Discophyllitid shells are rather similar to those of the ancestral Ussuritidae and are distinguished primarily by the more complex suture. The Discophyllitidae provided the source for the Jurassic Phylloceratidae and Juraphyllitidae. Four genera are recognized and described.Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ... Part L Mollusca 4, Ammonoidea, 1957 Discophyllitid genera *'' Discophyllites'': Discophyllitids in which the first lateral saddle of the suture is asymmetrically monophyllic, like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmoceratoidea
Desmoceratoidea, formerly Desmocerataceae, is a superfamily of Cretaceous ammonites, generally with round or oval-whorled shells that are mostly smooth or weakly ribbed and rarely tuberculate, but commonly with constrictions. a Paleobiology database retrieved on July 8, 2012. with and (1996), ''Mollusca 4 Revised , Cretaceous Ammonoidea'', vol. 4, in ''Treatise on Invertebrate Paleontology'', Part L (Roger L. Kaesler et el. eds.), Boulder, Colorado: The Geological Society of America & Lawrence, Kansas: University of Kansas Press, 67-111. Regarded as monophyletic, the Desmocerataceae are derived from the |
Ammonitida Families
Ammonitida is an order of Ammonoidea, ammonoid cephalopods that lived from the Jurassic through Paleocene time periods, commonly with intricate ammonitic sutures. Ammonitida is divided into four suborders, the Phylloceratina, Lytoceratina, Ancyloceratina, and Ammonitina. The Phylloceratina is the ancestral stock, derived from the Ceratitida near the end of the Triassic. The Phylloceratina gave rise to the Lytoceratina near the beginning of the Jurassic which in turn gave rise to the highly specialized Ancyloceratina near the end of the Jurassic. Both the Phylloceratina and Lytoceratina gave rise to various stocks combined in the Ammonitina. These four suborders are further divided into different stocks, comprising various families combined into superfamilies. Some like the Hildoceratoidea and Stephanoceratoidea are restricted to the Jurassic. Others like the Hoplitoidea and Acanthoceratoidea are known only from the Cretaceous. Still others like the Perisphinctoidea are found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incertae Sedis
' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by ' (of uncertain family), ' (of uncertain suborder), ' (of uncertain order) and similar terms. Examples *The fossil plant '' Paradinandra suecica'' could not be assigned to any family, but was placed ''incertae sedis'' within the order Ericales when described in 2001. * The fossil ''Gluteus minimus'', described in 1975, could not be assigned to any known animal phylum. The genus is therefore ''incertae sedis'' within the kingdom Animalia. * While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves ''incertae sedis''. It was later agreed to place them in a separate order, Cathartiformes. * Bocage's longbill, ''Motacilla bocagii' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
