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Eoderocerataceae
Eoderoceratoidea is a superfamily of true ammonites (suborder Ammonitina) 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''.Donovan,D.T., Callomon and Howarth 1981. Classification of the Jurassic Ammonitina; Systematics Association. Arkell ''et al.'', 1957. Mesozoic Ammonoidea, in Treatise on Invertebrate Paleontology, (Part L); Geological Soc. of America and University of Kansas press The earliest known eodoceroceratoidean is the eoderoceratid genus ''Microderoceras''. Although its origin is uncertain, it is likely that it is derived from the Psiloceratoidea. It has also been proposed, with some imagination, that ''Microderoceas'' has its origin some earlier Jurassic lytoceratid such as ''Analytoceras''. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonard Frank Spath
Leonard Frank Spath FRS (20 October 1882 – 2 March 1957) was a British geologist specialising in malacology and ammonitology. Education Spath gained a Bachelor of Science degree in geology at Birkbeck College in 1912 and obtained employment at the British Museum as an assistant curator in the geology department. He undertook two geology field trips, to Tunisia and Newfoundland, around that time which he used as an opportunity to collect fossils. He later gained a Doctor of Science degree from the University of London and was a lecturer in Geology at Birkbeck, University of London. Awards and honours Spath was elected a Fellow of the Royal Society (FRS) in 1940, his certificate of election reads: Spath won the prestigious annual scientific Lyell Medal given by the Geological Society of London The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liparoceras
Liparoceras is an extinct fossil ammonite species from the Early Jurassic period of England, and is found in lower Lias deposits. Its name means 'fat head' and this is due to its broad shell. The venter is wide and finely ribbed with no keel and it has two rows of tubercules on each whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral .... Distribution Jurassic deposits of Argentina, Europe, British Columbia and North Africa. References *Arkell ''et al.'', 1957. Mesozoic Ammonoidea, in Treatise on Invertebrate Paleontology, (Part L); Geological Soc. of America and University of Kansas press. External links ''Liparoceras'' at fossilmuseum.net Ammonitida genera Liparoceratidae Jurassic ammonites Fossils of Great Britain Pliensbachian life {{Ammonitina-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Ammonites
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 Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonitida Superfamilies
Ammonitida is an order of 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 in bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoderoceratoidea
Eoderoceratoidea is a superfamily of true ammonites (suborder Ammonitina) 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''.Donovan,D.T., Callomon and Howarth 1981. Classification of the Jurassic Ammonitina; Systematics Association. Arkell ''et al.'', 1957. Mesozoic Ammonoidea, in Treatise on Invertebrate Paleontology, (Part L); Geological Soc. of America and University of Kansas press The earliest known eodoceroceratoidean is the eoderoceratid genus ''Microderoceras''. Although its origin is uncertain, it is likely that it is derived from the Psiloceratoidea. It has also been proposed, with some imagination, that ''Microderoceas'' has its origin some earlier Jurassic lytoceratid such as ''Analytoceras'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hildocerataceae
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.Arkell ''et al.'', Treatise on Invertebrate Paleontology, Part L Ammonoidea, (1956) Hildoceratoidea is an upper Lower to lower Middle Jurassic group belonging to the Ammonitina that unites the Hildoceratidae, Hammatoceratidae, Graphoceratidae, and Sonniniidae. In some taxonomies the name Phymatoceratidae is substituted for the Hammatoceratidae Hildoceratidae, which is the ancestral family, is derived from the Acanthopleuroceratinae, a subfamily in the Eoderoceratoidean family, Polyorphitidae. The Stephanoceratoidea, Perisphinctoidea, and Haploceratoidea have their source in the Hammatoceratidae which is derived from the Hildoceratidae. References Hildoceratoidea, Jurassic ammonites Ammonitida superfamilies Ammonitina Early Jurassic first app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analytoceras
''Analytoceras'' is an extinct genus of cephalopod belonging to the Ammonite subclass that lived during the early Jurassic. ''Analytoceras'', named by Alpheus Hyatt in 1900, is a 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. ... and only member of the pleuroacanthitid subfamily Analytoceratinae, which has the same characters as its genus. Shell characters: inner whorls constricted, middle with parabolic lines and conspicuous parabolic nodes, outer with sigmoidal flairs; adult body chamber with ventrolateral spines. References * W.J Arkell, B.Kummel, C.W. Wright, Systematic Descriptions, Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L (1957) p L193. {{Taxonbar, from=Q4751165 Early Jurassic ammonites of Europe Fossil taxa described in 1900 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lytoceratina
Lytoceratina is a suborder of Jurassic and Cretaceous 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 Ussuritidae or Discophyllitidae, familie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psiloceratoidea
Psiloceratoidea is a superfamily of Early Jurassic ammonoid cephalopods proposed by Hyatt in 1867, assigned to the order Ammonitida. They were very successful during Hettangian and Sinemurian. Last of them, family Cymbitidae and genera '' Hypoxynoticeras'' and '' Radstockiceras'' survived into Early Pliensbachian. Psiloceratoidea is probably derived from the family Ussuritidae, which were Triassic members of Phylloceratoidea. Similar to their ancestors, Psiloceratidae kept smooth, rounded venter for whole of their life. Schlotheimiidae were different, as they had ventral chevrons. Rest of the families had angular venter, or keel for at least part of their ontogeny. Most of the members of this superfamily had only simple ribs, but few of them have evolved also secondary ribbing. While some members are involute and some Oxynoticeratidae were oxycone, most of the species were evolute. Families *Psiloceratidae - Evolute shells with simple, or missing ribs. An venter, there is no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microderoceras
''Microderoceras'' is a flat sided, evolute, radially ribbed Lower Jurassic ammonite belonging to the ammonitid family Eoderoceratidae and superfamily Eoderoceratoidea. Its whorls are subquadrangular in section; venter on the outer rim, rounded; sides with two rows if distinct spines, tubercles on internal molds, formed at either end of the ribs. The lateral surface of the ribcage is concave toward both sides, the lateral side of the dorsal and the lateral side of the ventral surface. The ribs are divided into six pairs (1-3) of the following types: 2-3 is the only type. In the first type, the ribs on the ventral face are fused to the ribs on the ventral sides; the ribs on the dorsal face are fused to the ribs on the dorsal sides. The second type represents the ribbed body, the ribs are in the same arrangement as in the first type and the rib cage does not fuse to the dorsal surface. These shelled cephalopods, named by Alpheus Hyatt in 1871, are part of the now extinct Ammonoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amaltheidae
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 (discoidal evolute shells) with quadrate whorls, typically with crenulated keels; involving all together four genera. Donovan in Donovan ''et al.'' (1981) retains the Amaltheidae in the sense of Arkell, ''et al.'' 1957, as shown in the Treatise but synonymizes ''Pseudoamaltheus'' with ''Amaltheus'', (a subgenus in the Treatise), reducing the number of valid genera to three. These are ''Amaltheus'', ''Amauroceras'', and '' Pleuroceras''. ''Amaltheus'' is oxyconic, keeled, strigated, and ribbed on the outer flanks. ''Amauroceras'' is smooth, compressed, without ribs or stigation, and the keel is reduced. '' Pleuroceras'' has a pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
