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Cyclophoridae Incertae Sedis
Cyclophoridae is a taxonomic family of small to large tropical land snails with an operculum, terrestrial gastropod mollusks in the order Architaenioglossa belonging to the subclass Caenogastropoda (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). This diverse family with many species is now limited to the representatives in the tropics and subtropics of the Old and New World. Their fossil history dates back through the Early Tertiary to the Cenomanian age of the Cretaceous. Description The dextral shells are mostly of small and rarely medium size. The form of the shell varies from discoidal to turbinate. The round aperture is often modified, sometimes with an incision or a constriction. The last whorl can sometimes be disconnected and then extends strongly from the winding plane. The operculum is generally circular, which can be retracted deeply into the shell. Its form is multispiral and can be calcified or lacking calcareous overlay. The outer la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name. As a unit of geologic time measure, the Cenomanian Age spans the time between 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya. The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States. At the end of the Cenomanian, an anoxic event took place, called the Cenomanian-Turonian boundary event or the "Bonarelli event", that is associated with a minor extinction event for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Schindewolf
Otto Heinrich Schindewolf (7 June 1896 – 10 June 1971) was a German paleontologist who studied the evolution of corals and cephalopods. Biography Schindewolf was on the faculty at the University of Marburg from 1919 until 1927. Then he became director of the Geological Survey of Berlin. In 1948 he became a professor at the University of Tübingen, where he retired as professor emeritus in 1964. He was a saltationist who opposed the theory of gradual evolution, and in the 1930s suggested that major evolutionary transformations must have occurred in large leaps between species. This idea became known as the Hopeful Monster theory and was further taken and developed up by the geneticist Richard Goldschmidt in the 1940s. Schindewolf was also the first to suggest, in 1950, that mass extinctions might have been caused by extraterrestrial impacts or nearby supernova. From 1948 until his retirement in 1964, Schindewolf was professor of Geology and Paleontology at the Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm August Wenz
Wilhelm August Wenz (21 October 1886 – 12 September 1945) was a German malacologist, born in Frankfurt am Main. He is the author of the 7-part Gastropoda The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. ... section of ''Handbuch der Paläozoologie'' (1938-1944), a very important review that described all known fossil genera. Only a few copies of this rare work survive: almost the entire stock of later editions was destroyed during the Second World War. Bibliography (incomplete) * Fischer K. & Wenz W. A. (1914''Die Landschneckenkalke des Mainzer Beckens und ihre Fauna'' * Wenz W. (1923-1930) "Gastropoda extramarina tertiaria" ''Fossilium catalogus, I: Animalia''. 3387 pp., published in parts. * Wenz W. (1938-1944) ''Teil 1: Allgemeiner Teil und Prosobranchia''. In: Schin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioecious
Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is biparental reproduction. Dioecy has costs, since only about half the population directly produces offspring. It is one method for excluding self-fertilization and promoting allogamy (outcrossing), and thus tends to reduce the expression of recessive deleterious mutations present in a population. Plants have several other methods of preventing self-fertilization including, for example, dichogamy, herkogamy, and self-incompatibility. Dioecy is a dimorphic sexual system, alongside gynodioecy and androdioecy. In zoology In zoology, dioecious species may be opposed to hermaphroditic species, meaning that an individual is either male or female, in which case the synonym gonochory is more often used. Most animal species are dio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radula
The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus. The radula is unique to the molluscs, and is found in every class of mollusc except the bivalves, which instead use cilia, waving filaments that bring minute organisms to the mouth. Within the gastropods, the radula is used in feeding by both herbivorous and carnivorous snails and slugs. The arrangement of teeth ( denticles) on the radular ribbon varies considerably from one group to another. In most of the more ancient lineages of gastropods, the radula is used to graze, by scraping diatoms and other microscopic algae off rock surfaces and other substrates. Predatory marine snails such as the Naticidae use the radula plus an acidic secretion to bore through the shell of other molluscs. Other predatory marine sn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proboscis
A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elongated nose or snout. Etymology First attested in English in 1609 from Latin , the latinisation of the Ancient Greek (), which comes from () 'forth, forward, before' + (), 'to feed, to nourish'. The plural as derived from the Greek is , but in English the plural form ''proboscises'' occurs frequently. Invertebrates The most common usage is to refer to the tubular feeding and sucking organ of certain invertebrates such as insects (e.g., moths, butterflies, and mosquitoes), worms (including Acanthocephala, proboscis worms) and gastropod molluscs. Acanthocephala The Acanthocephala or thorny-headed worms, or spiny-headed worms are characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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