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Ermoceras
''Ermoceras'' is a genus of ammonite belonging to the Thomboceratidae family of the Middle Jurassic ( u Baj) found in deposites of central Arabia, Sinai, and Algeria with strong primary and secondary ribs and a single row of lateral tubercles; described as having a deep ventral groove Arkell et al 1957, Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Ammonoidea ''Telermoceras'', with low, depressed whorls, and ''Kosmermoceras'' with high, compressed whorls are considered subgenera of ''Ermoceras'' Both are from the same time and region. ''Telermoceras'' has coarse secondary ribs and a deep umbilicus surrounded by large tubercles or spines. ''Kosmermoceras''has fine sharp to coarse ribbing and a flattish venter ''Ermoceras'' ''s.l.'' is derived from '' Arkelloceras''. Westermann (1965)Westernamm ,G. E. G. 1965.Septal and Sutural Patterns in Evolution and Taxonomy of Thamboceratidae and Clydoniceratidae (M Jurassic Ammonitina).Jour of Paleontology 39(5)864 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ermoceras Deserti
''Ermoceras'' is a genus of ammonite belonging to the Thomboceratidae family of the Middle Jurassic ( u Baj) found in deposites of central Arabia, Sinai, and Algeria with strong primary and secondary ribs and a single row of lateral tubercles; described as having a deep ventral groove Arkell et al 1957, Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Ammonoidea ''Telermoceras'', with low, depressed whorls, and ''Kosmermoceras'' with high, compressed whorls are considered subgenera of ''Ermoceras'' Both are from the same time and region. ''Telermoceras'' has coarse secondary ribs and a deep umbilicus surrounded by large tubercles or spines. ''Kosmermoceras''has fine sharp to coarse ribbing and a flattish venter ''Ermoceras'' ''s.l.'' is derived from '' Arkelloceras''. Westermann (1965)Westernamm ,G. E. G. 1965.Septal and Sutural Patterns in Evolution and Taxonomy of Thamboceratidae and Clydoniceratidae (M Jurassic Ammonitina).Jour of Paleontology 39(5)864 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ermoceras Inerme
''Ermoceras'' is a genus of ammonite belonging to the Thomboceratidae family of the Middle Jurassic ( u Baj) found in deposites of central Arabia, Sinai, and Algeria with strong primary and secondary ribs and a single row of lateral tubercles; described as having a deep ventral groove Arkell et al 1957, Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Ammonoidea ''Telermoceras'', with low, depressed whorls, and ''Kosmermoceras'' with high, compressed whorls are considered subgenera of ''Ermoceras'' Both are from the same time and region. ''Telermoceras'' has coarse secondary ribs and a deep umbilicus surrounded by large tubercles or spines. ''Kosmermoceras''has fine sharp to coarse ribbing and a flattish venter ''Ermoceras'' ''s.l.'' is derived from '' Arkelloceras''. Westermann (1965)Westernamm ,G. E. G. 1965.Septal and Sutural Patterns in Evolution and Taxonomy of Thamboceratidae and Clydoniceratidae (M Jurassic Ammonitina).Jour of Paleontology 39(5)864 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stephanoceratidae
Stephanoceratidae is a family of planulate and coronate ammonites within the Stephanoceratoidea.Arkell, Kummel, and Wright, 1957. Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Shells are evolute so that all whorls are exposed and have strong ribbing that bifurcates, that is splits in two, on the flanks. Many have tubercles at the point of bifurcation. Whorl sections are generally subequant; the outer rim, or venter, commonly rounded. Stephanoceratidae is derived from the Otoitidae Otoidtidae: stephanoceratoid ammonitina from the early Middle Jurassic that begin as cadicones but become more planualte with age; derived from the Hammitoceratidae (Hildoceratoidea), probably through '' Erycites'' by way of ''Abbasites''. Sh .... Their fossils are found in upper Middle- and lower Upper Jurassic sediments. Subfamilies and genera * Cadomitinae * Frebolditinae * Garantianinae * Mollistephaninae * Stephanoceratinae *'' Ermoceras'' *'' Kosmermoceras' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arkelloceras
''Arkelloceras'' is an early Middle Jurassic (Bajocian stage) Stephanoceratoid (Ammonitina) genus from arctic Canada, Alaska, and Siberia belonging to the family Otoitidae (Imlay 1984, Westermann 1965) ''Arkelloceras'' seems to be a direct descendant of ''Abbasites'' and is thought to have given rise to ''Ermoceras ''Ermoceras'' is a genus of ammonite belonging to the Thomboceratidae family of the Middle Jurassic ( u Baj) found in deposites of central Arabia, Sinai, and Algeria with strong primary and secondary ribs and a single row of lateral tubercles ...'' and possibly to '' Thamboceras''. (Westermann 1965) ''References'' * Imlay, Ralph W. 1984. Early and Middle Bajocian (Middle Jurassic) Ammonites from Southern Alaska;U.S.G.S PP 132* Westermann, G. E. G. 1965.Septal and Sutural Patterns in Evolution and Taxonomy of Thamboceratidae and Clydoniceratidae (M Jurassic Ammonitina). Jour of Paleontology 39(5)864-874, Sept. {{Taxonbar, from=Q4791959 Jurassic ammonites ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bajocian
In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.3 Ma to around 168.3 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age. Stratigraphic definitions The Bajocian Stage takes its name from the Latin name (Bajocae) of the town of Bayeux, in the region of Normandy in France. The stage was named and introduced in scientific literature by French palaeontologist Alcide d'Orbigny in 1842. The base of the Bajocian stage is defined as the place in the stratigraphic column where fossils of the ammonite genus ''Hyperlioceras'' first appear. A global reference profile (a GSSP) for the base is located at Murtinheira, close to Cabo Mondego in Portugal.The GSSP is described by Pavia & Enay (1997) The top of the Bajocian (the base of the Bathonian) is at the first appearance of ammonite species ''Parkinsonia convergens''. Subdivision The Bajocian is often divided into Lower/Early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bajocian Life
In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.3 Ma to around 168.3 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age. Stratigraphic definitions The Bajocian Stage takes its name from the Latin name (Bajocae) of the town of Bayeux, in the region of Normandy in France. The stage was named and introduced in scientific literature by French palaeontologist Alcide d'Orbigny in 1842. The base of the Bajocian stage is defined as the place in the stratigraphic column where fossils of the ammonite genus ''Hyperlioceras'' first appear. A global reference profile (a GSSP) for the base is located at Murtinheira, close to Cabo Mondego in Portugal.The GSSP is described by Pavia & Enay (1997) The top of the Bajocian (the base of the Bathonian) is at the first appearance of ammonite species ''Parkinsonia convergens''. Subdivision The Bajocian is often divided into Lower/Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Animals Of Africa
The Jurassic ( ) is a geologic period and 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 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. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassic, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
