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Mariella Mosler
''Mariella'' is an ammonoid genus, named by Nowak (1916) from the upper Albian and Cenomanian stages of the mid Cretaceous, included in the Turrilitidae. Its type is ''Turrilites bergeri'' Description ''Mariella'' resembles ''Turrilites'' in general form. The shell is asymmetric, closely wound in a long expanding trochoidal spire. Ribs are slightly oblique and are rather feeble, each with 4 more or less equally spaced tubercles. ''Turrilites'' differs primarily in being more strongly ribbed and in having a more oval aperture. Distribution Fossils of ''Mariella'' have been found in Angola, Antarctica, Australia, Brazil, Canada (British Columbia), Colombia ( Hiló Formation), France, Germany, Iran, Japan, Kazakhstan, Madagascar, Mexico, Mozambique, New Zealand, South Africa, Spain, Switzerland, Turkmenistan, Ukraine, the United Kingdom, and the United States (California, Texas, Oregon). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonoidea
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) than they are to shelled nautiloids such as the living ''Nautilus'' species. The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Ammonites are excellent index fossils, and linking the rock layer in which a particular species or genus is found to specific geologic time periods is often possible. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found. The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder ( 79 AD nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
