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Lytoceratid
Lytoceratidae is a taxonomic family of ammonoid cephalopods belonging to the suborder Lytoceratina, characterized by very evolute shells that generally enlarge rapidly, having whorls in contact but mostly overlapping very sightly, or not at all. Surface ornament may consist of various combinations of straight or crinkled growth lines, flares, constrictions, and, more rarely, plications. Sutures are highly complex and moss-like, but with few major elements. Lateral lobes are widely splayed and blunt, or with obliquely deflected end. The external, ventral, lobe is short. The Lytoceratinae have a worldwide distribution and a stratigraphic range extending from the middle Lower Jurassic (Pliensbachian) to the early Upper Cretaceous (Cenomanian). Subfamilies The Lytoceratidae has been divided into four subfamilies, as follows. * Lytoceratinae Neumayr 1875 (Pliensbachian) ** ''Ammonoceratites'' Bowditch 1822 ** ''Argonauticeras'' Anderson 1938 ** '' Carinolytoceras'' Wiedmann 1962 * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lytoceratidae
Lytoceratidae is a taxonomic family of ammonoid cephalopods belonging to the suborder Lytoceratina, characterized by very evolute shells that generally enlarge rapidly, having whorls in contact but mostly overlapping very sightly, or not at all. Surface ornament may consist of various combinations of straight or crinkled growth lines, flares, constrictions, and, more rarely, plications. Sutures are highly complex and moss-like, but with few major elements. Lateral lobes are widely splayed and blunt, or with obliquely deflected end. The external, ventral, lobe is short. The Lytoceratinae have a worldwide distribution and a stratigraphic range extending from the middle Lower Jurassic (Pliensbachian) to the early Upper Cretaceous (Cenomanian). Subfamilies The Lytoceratidae has been divided into four subfamilies, as follows. * Lytoceratinae Neumayr 1875 (Pliensbachian) ** '' Ammonoceratites'' Bowditch 1822 ** '' Argonauticeras'' Anderson 1938 ** '' Carinolytoceras'' Wiedmann 196 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lytoceratina
Lytoceratina is a Suborder (biology), suborder of Jurassic and Cretaceous Ammonitida, ammonites that produced loosely coiled, evolute and gyroconic shells in which the sutural element are said to have complex moss-like endings. Morphologic characteristics Shells are generally evolute, with all whorls exposed and touching, some are gyroconic with whorls separated by a space. Whorl sections vary from subcircular to narrowly compressed. The venter, or outer rim, is generally broadly arched but in some is keeled. Sides are either smooth or ribbed. Sutural elements are typically complex, referred to in the literature as moss-like, with adventious and secondary subdivisions. Saddle endings tend to be rounded but usually not phylloid, lobes tend to be more jagged with thorn-like endings. Aptychi are single valved and concentrically striated (Anaptychus) Derivation and phylogeny The Lytoceratina, which constitute a suborder within the Ammonitida, are derived from the Triassic Ussuriti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lytoceras Cornucopia
''Lytoceras cornucopia'' is an ammonite species belonging to the family Lytoceratidae. These cephalopods were fast-moving nektonic carnivores. They lived in the Jurassic period. Description Shells of ''Lytoceras cornucopia'' can reach an average diameter of about . Distribution Fossils of species within this genus have been found in the Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), 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 J ... rocks of France, Hungary, Italy, Luxembourg and United Kingdom. References External linksAmmonites Jurassic ammonites [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protetragonites
''Protetragonites'' is an extinct genus of ammonoid cephalopods belonging to the family Lytoceratidae. These fast-moving nektonic carnivores lived from the Jurassic period Tithonian age to the Cretaceous period Aptian age.Sepkoski, JacSepkoski's Online Genus Database – Cephalopoda/ref> Species * ''Protetragonites crebrisulcatus'' Uhlig, 1883 * ''Protetragonites obliquestrangulatum'' (Kilian, 1889) * ''Protetragonites quadrisulcatus'' d'Orbigny, 1841 * ''Protetragonites zuegeli'' Maisch & Salfinger-Maisch, 2016 Description Shells of ''Protetragonites'' species reach a diameter of about . Shells show few constrictions and a circular or triangular section. Distribution Fossils of species within this genus have been found in the Cretaceous rocks of Austria, Canada, Czech Republic, Slovakia, Dominican Republic, France, Hungary, Madagascar, Morocco, Poland, Spain, Russia, Ukraine, Western Sahara, as well in the Jurassic The Jurassic ( ) is a Geological period, geologic period a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audaxlytoceras
''Audaxlytoceras'' is an extinct genus of lytoceratid ammonites. Taxonomy The Middle Jurassic '' Nannolytoceras'' is its closest relative. '' Aegolytoceras'' and '' Peripleuroceras'' Tutcher and Trueman 1925 are synonyms. Fossil record This genus is known in the fossil record from the Lower Jurassic (Pliensbachian) (from about 190.8 to 182.7 million years ago). Fossils of species within this genus have been found in France, Germany, Italy, Morocco and Spain. Description Its shell is small, smooth, evolute (all whorls showing), only slightly impressed dorsally (along the inner rim). Whorls are compressed, subquadrate in section, higher than wide, with few narrow constrictions. The suture relatively simple with a long ventral lobe and two lateral lobes.Arkell ''et al.'', 1957. Mesozoic Ammonoidea, Systematic Descriptions. Treatise on Invertebrate Paleontology Part L, Ammonoidea. Geol Soc of Amer. and Univ Kans. Press. L199 Bibliography *Arkell ''et al.'', 1957. Mesozoic Ammo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eulytoceras
''Eulytoceras'' is an extinct genus of ammonoid cephalopods belonging to the family Lytoceratidae. These fast-moving nektonic carnivores lived in the Cretaceous period, from Hauterivian age to Barremian age.Sepkoski, JacSepkoski's Online Genus Database – Cephalopoda/ref> Species * ''Eulytoceras anisoptychum'' Uhlig, 1883 * ''Eulytoceras inaequalicostatus'' d'Orbigny, 1840 * ''Eulytoceras phestum'' Matheron, 1878 Description Shells of ''Eulytoceras'' species reach a diameter of about . Distribution Fossils of species within this genus have been found in the Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ... rocks of Antarctica, Austria, Canada, Italy, Madagascar, South Africa and Spain. References Cretaceous ammonites Fossils of Antarctica Ammonitida genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lytoceratinae
Lytoceratinae is a subfamily of ammonoid cephalopods that make up part of the family Lytoceratidae. Description They are characterized by shells in which the whorls bear growth lines or lamellar folds, or both, commonly corresponding to constrictions in the internal mold. The external suture, that not lying against the previous whorl, has two lateral lobes (per side), the first being much larger. The internal lobe, which lies against the previous whorl, has a cruciform dorsal lobe. Fossil range Lytoceratinae has a long stratigraphic and temporal range (196.5 to 89.3 Ma ) extending from the Early Jurassic Pliensbachian to the Late Cretaceous Cenomanian, although most included genera have much shorter ranges. ''Lytoceras'', the type genus, ranges from Early Jurassic to early late Cretaceous.Sepkoski, JacSepkoski's Online Genus Database – Cephalopoda/ref> '' Ptycholytoceras'' is confined to the Early Jurassic Toarcian, while '' Hemilytoceras'' is present in the Late Jurassic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonoceratites
''Ammonoceratites'' is an extinct genus of ammonoid cephalopod known from the Albian (upper Lower Cretaceous) of British Columbia, Madagascar, New Zealand, and Japan, included in the Lytoceratidae. The shell of ''Ammonoceratites'' is evolute, smooth, moderately expanded; the inner rim (dorsum) only slightly impressed; whorl section subcircular. It is similar to that of ''Lytoceras'' which has transverse ribbing and to that of ''Pictetia ''Pictetia'' is a genus of about eight species of trees and shrubs in the legume family with Thorns, spines, and prickles, spiny stems and (in six of the eight species) spine-tipped leaflets.Beyra & Lavin (1999), pp.36–38 The genus is endemism, ...'' which is gyroconic (whorls not touching) and more strongly expanded. References *Arkell ''et al.'', 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L; Geological Society of America and University of Kansas press. *C. W. Wright, J. H. Calloman, and M. K. Howarth. 1996. Cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argonauticeras
''Argonauticeras'' is an extinct ammonoid cephalopod genus that lived during the latter part of the Early Cretaceous, included in the Lytoceratida and found in lower and possibly middle Aptian marine sediments. It has been thought of as a subgenus of ''Ammonoceratites''. ''Argonauticeras'' produced an evolute shell with a trapezoidal whorl section, slightly impressed inner rim (or dorsum), a somewhat flattened outer rim (venter) and broadly arched sides, covered with fine, weakly crinkled ribs. References *W.J Arkell ''et al.'', 1957. Systematic Descriptions, Mesozoic Ammonoidea, 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 Ammonoidea. Cretaceous ammonites Fossils of Japan Fossils of Madagascar Aptian life Ammonitida gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lytoceras
''Lytoceras'' is an ammonite genus that was extant during most of the Jurassic and Cretaceous periods, and is the type genus for the family Lytoceratidae. These cephalopods were fast-moving nektonic carnivores. Description Shells of ''Lytoceras'' are evolute, round or quadrate in section, covered with crinkled growth lines or riblets, and may have slight constrictions on internal molds. Some have fine striations, (parallel grooves running longitudinally along the flanks). Distribution Fossils of species within this genus have been found in the Jurassic and Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ... rocks all over the world, particularly in Western Europe, Morocco, Madagascar, South Africa and United States. References *Systematic descriptions, Mesozoic Ammo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalytoceratinae
Megalytoceratinae is a subfamily of lytoceratids ammonites consisting of planulate forms, i.e. those with moderately evolute compressed shells with bluntly rounded venters, in which the outer whorls become smooth and sutures tend to resemble those of the Perisphinctidae. The family includes three genera, '' Megalytoceras'', and '' Metrolytoceras'', from the Middle Bajocian of England, '' Perilytoceras'' from the Toarcian The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian ... and a fourth possible member, '' Asapholytoceras'', from the Toacian of southeastern Europe. References *W.J.Arkell, B.Kummel, & C.W.Wright 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L Ammonoidea. R.C.Moore, (ed). Jurassic ammonites Toarcian first appearances Middle Jurassic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemilytoceras
''Hemilytoceras'' is a lytoceratin ammonite genus with round inner whorls, outer whorls becoming depressed and in some developing high lamellae (ribs) that bend forward over the venter. The type species ''H. immanae'' came from the Tithonian of Europe. The genus is known from the overall Upper Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ... of central and southern Europe, North Africa, and western India. References * W.J.Arkell ''et al.'', 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L. Geological Society of America and Univ Kansas press. Jurassic ammonites Ammonites of Europe Tithonian life Ammonitida genera Lytoceratidae {{ammonitida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |