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Velebites
''Velebites'' is a genus of middle Triassic ammonites from the Balkans belonging to the Aplococeratidae, a family within the Ceratitida. It is somewhat similar to ''Aplococeras ''Aplococeras'' is an evolute discoidal ceratitid ammonite from the Middle Triassic Ladinian stage, found in southern Europe and Nevada. Whorl sides are convex, converging on a rounded venter (the outer rim), and are ornamented with slightly flex ...'' in external form. The shell is evolute, discoidal with convex converging whorl sides and rounded venter. Ribs are more recurved than in ''Aplococeras'' and the suture is ceratitic rather than goniatitic. References * Treatise on Invertebrate Paleontology Part L Mollusca 4 Aplococeratidae Ceratitida genera Triassic animals of Asia {{Ceratitida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplococeratidae
Aplococeratidae is a family of ceratitids from the Middle Triassic with very simplified sutures and a tendency to lose their ornamentation. Shells are generally evolute, more or less compressed, with rounded venters. Ornamentation if present consists of umbilical ribs that disappear outwardly, toward the venter. The suture is ceratitic or goniatitic. Arkell ''et al.'' (1957), in the Treatise on Invertebrate Paleontology, Part L included the Aplococeraitdae in the Ceratitaceae, whereas E. T. Tozer in 1981 includes them in the Danubitaceae The Danubitoidea is a large and diverse superfamily in the order Ceratitida of the Ammonoidea that combines five families removed from the Ceratitaceae, Clydonitaceae, and Ptychitaceae. Taxonomy Superfamily Danubitoidea * Family Aplococeratidae ..., established by Spath, also in 1951. Genera included in the Aplococeratidae are '' Aplococeras'' (type), '' Apleuroceras'', '' Epiceratites'', '' Laboceras'', '' Metadinarites'', '' Pseudaplococ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplococeras
''Aplococeras'' is an evolute discoidal ceratitid ammonite from the Middle Triassic Ladinian stage, found in southern Europe and Nevada. Whorl sides are convex, converging on a rounded venter (the outer rim), and are ornamented with slightly flexuous {{Short pages monitor [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratitida
Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post Triassic ammonites. Ceratitids overwhelmingly produced planospirally coiled discoidal shells that may be evolute with inner whorls exposed or involute with only the outer whorl showing. In a few later forms the shell became subglobular, in others, trochoidal or uncoiled. Sutures are typically ceratitic, with smooth saddles and serrate or digitized lobes. In a few the sutures are goniatitic while in others they are ammonitic. Taxonomy * Ceratitida **Ceratitoidea ** Choristoceratoidea **Clydonitoidea **Danubitoidea **Dinaritoidea ** Lobitoidea ** Meekoceratoidea ** Megaphyllitoidea ** Nathorstitoidea **Noritoidea ** Otoceratoidea ** Pinacoceratoidea **Ptychitoidea ** Sageceratoidea **Tropitoidea ** Xenodiscoidea Only eight superfamilies are sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratitida Genera
Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post Triassic ammonites. Ceratitids overwhelmingly produced planospirally coiled discoidal shells that may be evolute with inner whorls exposed or involute with only the outer whorl showing. In a few later forms the shell became subglobular, in others, trochoidal or uncoiled. Sutures are typically ceratitic, with smooth saddles and serrate or digitized lobes. In a few the sutures are goniatitic while in others they are ammonitic. Taxonomy * Ceratitida **Ceratitoidea **Choristoceratoidea **Clydonitoidea **Danubitoidea **Dinaritoidea ** Lobitoidea ** Meekoceratoidea ** Megaphyllitoidea ** Nathorstitoidea **Noritoidea **Otoceratoidea **Pinacoceratoidea **Ptychitoidea ** Sageceratoidea **Tropitoidea **Xenodiscoidea Only eight superfamilies are shown i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
