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Placenticeras
''Placenticeras'' is a genus of ammonites from the Late Cretaceous. Its fossils have been found in Asia, Europe, North and South America. Taxonomy ''Placenticeras'', named by Fielding Bradford Meek, 1870, is the type genus for the Placenticeratidae, a family that is part of the Hoplitoidea, a superfamily of the Ammonitida. Description ''Placenticeras'' has a very involute shell with slightly convex sides and a very narrow venter. Side are smooth or with faint sinuous ribs. Early whorls have umbilical tubercles that in later whorls appear higher on the sides. Earlier whorls normally have lower and fine upper ventrolateral clavi. Ornament weakens in the adult and the last whorl may be smooth. The suture is with numerous adventitious and auxiliary elements, with saddles and lobes that are much frilled. Species Species list according t * ''Placenticeras bidorsatum'' * ''Placenticeras costatum'' * ''Placenticeras cumminsi'' * ''Placenticeras fritschi'' * ''Placenticeras grossouvrei' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placenticeras Fritschi
''Placenticeras'' is a genus of ammonites from the Late Cretaceous. Its fossils have been found in Asia, Europe, North and South America. Taxonomy ''Placenticeras'', named by Fielding Bradford Meek, 1870, is the type genus for the Placenticeratidae, a family that is part of the Hoplitoidea, a superfamily of the Ammonitida. Description ''Placenticeras'' has a very involute shell with slightly convex sides and a very narrow venter. Side are smooth or with faint sinuous ribs. Early whorls have umbilical tubercles that in later whorls appear higher on the sides. Earlier whorls normally have lower and fine upper ventrolateral clavi. Ornament weakens in the adult and the last whorl may be smooth. The suture is with numerous adventitious and auxiliary elements, with saddles and lobes that are much frilled. Species Species list according t * '' Placenticeras bidorsatum'' * '' Placenticeras costatum'' * ''Placenticeras cumminsi'' * '' Placenticeras fritschi'' * '' Placenticeras gros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
