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Ancyloceratidae
Ancyloceratidae is a family of heteromorphic Ammonitida, ammonites that lived during the Early Cretaceous. Their shells begin as a loose spiral with whorls not touching which then turns into a straight shaft that ends in a J-shape hook or bend at end. Coarse ribbing and spines are common. Ancyloceratidae is the type family for the Ancyloceratoidea and of the suborder Ancyloceratina. They are found in Lower Cretaceous, Barremian to perhaps Lower Albian sediments. Genera include: *''Ammonitoceras'' Dumas, 1876 *''Ancyloceras'' D'Orbigny, 1842 - type genus *''Ancylotropaeum'' Casey, 1980 *''Antarcticoceras'' Thomson, 1974 M.R.A. Thomson, « Ammonite faunas of the Lower Cretaceous of south-eastern Alexander Island », ''British Antarctic Survey Scientific Reports'', 80 (1974), p.1-44. *''Audouliceras'' Thomel, 1965 *''Australiceras'' Whitehouse, 1926 *''Caspianites'' Casey, 1961 *''Epancyloceras'' Spath, 1930 *''Epitroapeum'' Kakabadze, 1977 *''Helicancyloceras'' Klinger & Kennedy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarcticoceras
''Antarcticoceras'' is a genus of crioconic ammonites in the family Shasticrioceratidae. It lived during the Early Cretaceous Period. ''Antarcticioceras'' fossils can be found in the Cretaceous rocks of Antarctica and South America.M.R.A. Thomson, « Ammonite faunas of the Lower Cretaceous of south-eastern Alexander Island », ''British Antarctic Survey Scientific Reports'', 80 (1974), p.1-44. Taxonomy and evolution The type species of ''Antarcticoceras,'' ''A. antarcticum,'' was described from 6 (possibly 7) specimens that were recovered from Alexander Island: the largest antarctic island. When these specimens were first recovered, it was thought they represented an unknown taxon within the Ancyloderid subfamily Helicancyanae. Thmpson, M. 1971. Ammonite Faunas of south eastern Alexander Island and their stratigraphical significance. In: Aide, R. ed. Antarctic Geology and Geophysics This original hypothesis was made because the first two specimens recovered were smaller in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancyloceratoidea
Ancyloceratoidea, formerly Ancylocerataceae, is a superfamily of typically uncoiled and loosely coiled heteromorph ammonoids 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) ... established by Alpheus Hyatt in 1900, that may contain as many as 11 families, depending on the classification accepted. Taxonomy The taxonomy content, Family (biology), families, of the Ancycloceratoidea has grown over the year, partly with the addition of newly defined families and partly with the moving of families from other superfamilies. Arkell, ''et al.'' (1957) in the Treatise on Invertebrate Paleontology, Treatise Part L included just the Ancyloceratidae Meek 1876, Bochianitidae Spath 1922, Hemihoplitidae Spath 1924, and Heteroceratidae Hyatt 1900 within the Ancylocerataceae. The Crioceratitidae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shastoceras
''Shastoceras'' is a genus of extinct ammonites found in Lower Aptian sediments in Northern California. Although sometimes placed in the Heteroceratidae, a family characterized by a helically wound early portion, its form indicates it more likely belongs to the Ancyloceratidae. ''Shastoceras'' resembles '' Uhligia'' from the Lower Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is precede ... of Germany, except for being stouter. In both genera the initial portion is short and in general straight, followed by a more or less 180 deg. bend and a straight to moderately curved shaft ending in a hook. The shaft of ''Shastoceras'' is shorter and broader than that of ''Uhligia''. References * W.J. Arkell, et al., 1957. Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology, Part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancyloceratina
The Ancyloceratina were a diverse suborder of ammonite most closely related to the ammonites of order Lytoceratina. They evolved during the Late Jurassic but were not very common until the Cretaceous period, when they rapidly diversified and became one of the most distinctive components of Cretaceous marine faunas. They have been recorded from every continent and many are used as zonal or index fossils. The most distinctive feature of the majority of the Ancyloceratina is the tendency for most of them to have shells that are not regular spirals like most other ammonites. These irregularly-coiled ammonites are called heteromorph ammonites, in contrast to regularly coiled ammonites, which are called homomorph ammonites. Biology The biology of the heteromorph ammonites is not clear, but one certainty is that their uncoiled shells would have made these forms very poor swimmers. Open shells, particularly ones with spines and ribs, create a lot of drag; but more importantly, the orient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonitoceras
''Ammonitoceras'' is an extinct genus of cephalopod belonging to the ammonite subclass that lived during the latter part of the Early Cretaceous in what is now Europe and the transcaspian region. ''Ammonitoceras'' was named by Dumas, 1876, the type-species: ''Ammonitoceras ucetiae''.DUMAS Although the description doesn't mention a hook, as in ''Ancyloceras'' or '' Acrioceras'', ''Ammonitoceras'' is included in the Ancyloceratidae. However neither do '' Australiceras'' or ''Tropaeum'', which are also included. References *Arkell et al., 1957. 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, Geological Society of America and University of Kansas press. {{Taxonbar, from=Q2843691 Early Cretaceous ammonites of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australiceras
''Australiceras'' is an extinct ammonite genus from the upper part of the Early Cretaceous, Aptian stage, included in the family Ancyloceratidae. Description ''Australiceras'' has an evolute shell, coiled with all whorls showing in keeping with its inclusion in the Ancyloceratida. The inner, early, whorls bear ribs that alternate between those that are smooth and those the bear stout blunt or conical tubercles. Ribs on the outer whorls become free of tubercles and end up all smooth. ''Australiceras'' bears some resemblance to ''Tropaeum'' and ''Balearites ''Balearites'' is an extinct ancyloceratin genus included in the family Crioceratitidae, subclass Ammonoidea, from the Upper Hauterivian. The shell, or conch, of ''Balearites'' is planispiral; whorls compressed, fairly flat sided, barely in co ...'', both related genera. The type species is ''Australiceras jacki''. References ;Notes ;Bibliography * W. J. Arkell et al. 1957. Mesozoic Ammonoidea, Treatise on Invewrte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Cretaceous
Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eighteen miles southwest of Gloucester and fifteen miles northeast of Bristol. Lower Wick is within the civil ... Gloucestershire, England See also * Nizhny {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laqueoceras
''Laqueoceras'' is an extinct genus of cephalopod belonging to the Ammonite subclass. They were fast-moving nektonic Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms ... carnivores. References Psiloceratidae Ammonitida genera Jurassic ammonites Hettangian life {{Ammonitina-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
