Related Research Articles
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 than they are to shelled nautiloids such as the living Nautilus species. The earliest ammonites appeared during the Devonian, and the last species either vanished in the Cretaceous–Paleogene extinction event, or shortly after during the Danian epoch of the Paleocene.
In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma. The Sinemurian is preceded by the Hettangian and is followed by the Pliensbachian.
Lusitanosaurus is a genus of large basal thyreophoran dinosaur from the Sinemurian stage of Early Jurassic of Portugal. It is the second example of the group from the Lower Jurassic of Europe and it is the oldest known dinosaur from the Iberian Peninsula. It is based on a large left maxilla with teeth that was lost in the fire at Museu Nacional de História Natural e da Ciência, Lisbon, in 1978.
Abbasites is an extinct genus of ammonites from the early Middle Jurassic epoch, included in the ammonitid family Erycitidae.
Acanthohoplites is an extinct genus of ammonites in the family Parahoplitidae that lived in the Aptian and Early Albian stages of the Early Cretaceous.
Gleviceras is an ammonite genus that lived during the Early Jurassic Period, found in Canada, Hungary, Mexico and the United Kingdom.
Zugodactylites is an extinct genus of ammonite cephalopod from the lower Toarcian epoch of the Lower Jurassic, ammonite zone Fibulatum. Its fossils are found in Europe, Russia and Canada.
Oxynoticeras is an extinct genus of ammonite from the Early Jurassic of Europe and North America. This genus is characterized by its smooth shell, with almost invisible undulations on the flank, and a sharp keel.
Cadomites is an extinct ammonite genus from the superfamily Stephanoceratoidea that lived during the Middle Jurassic.
Hoploscaphites is an extinct ammonite genus from the Upper Cretaceous and the Lower Paleocene, included in the family Scaphitidae.
Sphenodiscus is an extinct genus of acanthoceratacean ammonite. The genus has been found from many continents and is thought to have had a large global distribution during the Maastrichtian stage of the Late Cretaceous. It was one of the last ammonoids to have evolved before the entire subclass became extinct at the end of the period during the Cretaceous–Paleogene extinction event.
Oxynoticeratidae is a family of true ammonites included in the superfamily Psiloceratoidea.
Cephalopod egg fossils are the fossilized remains of eggs laid by cephalopods. The fossil record of cephalopod eggs is scant since their soft, gelatinous eggs decompose quickly and have little chance to fossilize. Eggs laid by ammonoids are the best known and only a few putative examples of these have been discovered. The best preserved of these were discovered in the Jurassic Kimmeridge Clay of England. Currently no belemnoid egg fossils have ever been discovered although this may be because scientists have not properly searched for them rather than an actual absence from the fossil record.
Euomphaloceratinae is a subfamily of Upper Cretaceous ammonites included in the Acanthoceratidae, characterized by generally evolute shells with quadrate whorl sections that are strongly ribbed. Sutures are ammonitic, but not overly complex.
Radstockiceras is an extinct genus of lower Jurassic ammonite that lived from Oxynotum zone of upper Sinemurian to Raricostatum zone of lower Pliensbachian. Shells of these animals were oxycone and involute with umbilicus that took maximum of 12% of diameter in the case of outer whorls. On inner whorls, venter has been sharp, but then it became rounded. Faint ribs had falcoid shape, but sometimes, ribs could absent. Shells could have been large in their size. Suture has been very complex, similar to Oxynoticeras, but culmination at umbilical margin has been missing. Genus has been named after town of Radstock, in Somerset.
Paroxynoticeras is an extinct genus of lower Jurassic ammonite that lived during upper Sinemurian. Animals belonging to this genus had platyconic shells with compressed whorl section and could grow to large sizes. In the case of young specimens, umbilicum is small, but it increases in bigger specimens.. Last whorl is excentric, which can occur also in relative species, Paracymbites. While on the outer whorls, venter is always rounded, on inner whorls it can be both rounded or sharp. Ornamentation on inner whorls and suture is similar to Oxynoticeras, but in bigger specimens, ribs became straight, simple and blunt. In these bigger specimens, midlateral tubercules might be present.
Reynesocoeloceras is genus of ammonite that lived during the lower Pliensbachian stage of early Jurassic, ammonite zones Ibex—Davoei.
Porpoceras is genus of ammonite that lived during the early and middle Toarcian stage of early Jurassic. Members of this genus existed from uppermost part of the Harpoceras serpentinum zone to the Haugia variabilis zone. Their fossils were found in Europe, Asia, North America and South America.
Leyvachelys is an extinct genus of turtles in the family Sandownidae from the Early Cretaceous of the present-day Altiplano Cundiboyacense, Eastern Ranges, Colombian Andes. The genus is known only from its type species, Leyvachelys cipadi, described in 2015 by Colombian paleontologist Edwin Cadena. Fossils of Leyvachelys have been found in the fossiliferous Paja Formation, close to Villa de Leyva, Boyacá, after which the genus is named. The holotype specimen is the oldest and most complete sandownid turtle found to date.
References
 | This Ammonitina-related article is a stub. You can help Wikipedia by expanding it. |