Gastroliths, or gizzard stones, are small rocks kept by an animal inside its stomach or at an early part of the alimentary canal. The function of these is to mash up the food so digestion takes place faster. Typically, animals which do this do not have suitable teeth for grinding, and the gastroliths are a good substitute for this.
A second function, in aquatic animals, is that gastroliths can be used for ballast to make diving easier.
Several pieces of evidence are needed to show that a rock was used by a fossil animal to aid its digestion. First, the stone must be unlike the rock found in its geological vicinity. Secondly, it should be rounded and polished, because inside a gizzard any genuine gastrolith would grind against other stones and fibrous materials, like the action of a rock tumbler. Lastly, the stone must be found with the fossils of the animal which ingested it.
Among living vertebrates, gastroliths are common among crocodiles, alligators, herbivorous birds, seals and sea lions. Domestic fowl need access to "grit". Stones swallowed by ostriches can exceed a length of . Amphibians such as the Axolotl ingest rocks that are presumed to be gastroliths. Apparent microgastroliths have also been found in frog tadpoles. Ingestion of silt and gravel by tadpoles of various frog species improves buoyancy control.
Sauropod dinosaurs appear to have used stones to grind tough plant matter. An example of this is the early Cretaceous theropod "Caudipteryx zoui" from northeastern China. It was discovered with a series of small stones, in the area of its skeleton that would have corresponded with its abdominal region. Aquatic animals, such as plesiosaurs, may have used them as ballast, to help balance themselves or to decrease their buoyancy, as crocodiles do. Some fossil gastroliths are rounded and polished, many stones in living birds are not polished at all. Gastroliths associated with dinosaur fossils can weigh several kilograms.
Scute
A scute is a bony external plate or scale, as on the shell of a turtle, the skin of crocodiles or the feet of some birds.
Scutes are similar to scales and serve the same function. Unlike the scales of fish and snakes, which are formed from the epidermis, scutes are formed in the lower vascular layer of the skin and the epidermal element is only the top surface. Forming in the living dermis, the scutes produce a horny outer layer, that is superficially similar to that of scales.
The dermal base may contain bone and produce dermal armour. Scutes with a bony base are properly called osteoderms. Dermal scutes are also found in the feet of birds and tails of some mammals, and are believed to be the primitive form of dermal armour in reptiles.
The term is also used to describe the heavy armour of the armadillo and the extinct glyptodon, and is occasionally used as an alternative to scales in describing snakes or certain fish, such as sturgeon.
BepiColombo
BepiColombo is a planned European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) mission to the planet Mercury. The mission is still being planned. This means that the details of the mission are likely to change. Its planned launch date is 2014 and it is planned to arrive at Mercury in 2020.
Sputnik 2
Sputnik 2 was a Soviet Union spacecraft. It was the second spacecraft in the Sputnik programme. It was the first spacecraft to carry a living animal, a dog called Laika. It was launched on 3 October 1957 at Baikonur Cosmodrome. Scientists think that Laika died several hours after launch from overheating. The spacecraft went into orbit around Earth for roughly five months. It went down into Earth's atmosphere on 14 April 1958 and burned up.
Sputnik 2 was 4 metres (13 feet) high and its base diameter was 2 metres (6.6 feet). It was a cone-shaped and it had several different places for radio transmitters, a telemetry system, a programming unit, a regeneration and temperature control system for the spacecraft, and scientific instruments. Laika was put in a special area.
Michal Prokop
Michal Prokop (* August 13, 1946, Prague, Czechoslovakia, today Czech Republic) is a Czech singer, songwriter and politician. He is member of Framus Five. In 2007 he was inducted into the Beatová síň slávy (Beat Hall of Fame).
Megali Idea
The Megali Idea was an idea in Greek nationalism since the end of the Byzantine Empire. The goal of Megali Idea was the liberation of all Greek-inhabited lands occupied by Ottoman Empire.
Paula Fernandes
Paula Fernandes de Souza (born August 28, 1984) is a Brazilian sertanejo and country singer.
Nodosauridae
The Nodosauridae is a family of ankylosaur dinosaurs, from Upper Jurassic to Upper Cretaceous strata of what are now North America, Asia, Antarctica and Europe. They are the family of ankylosaurs which do not have club-shaped tails. They often have spikes protecting their head and shoulders.
All nodosaurs, like other ankylosaurs, are medium-sized to large, heavily built quadrupedal herbivorous dinosaurs, with small denticulate teeth and rows of osteoderms (a type of armour) on the dorsolateral (top and sides) surfaces of the body.
The following taxonomy follows Thompson "et al.", 2011 unless otherwise noted.
The clade Nodosauridae may be defined as "all ankylosaurs closer to "Panoplosaurus" than to "Ankylosaurus". Vickaryous "et al." considered the most primitive member of the Nodosauridae to be "Cedarpelta". A cladogram from a 2011 analysis is shown by Richard S. Thompson and colleagues.
French grammar
French grammar is the rules about how to speak and write the French language. It is similar to the grammar of other Romance languages.
French is moderately inflected. This means that some words change their form in different situations.
In French, verbs are conjugated to show information. That means they change endings.
Verbs are conjugated to match with grammatical person.
Most French verbs are regular, which means that the someone can guess how to conjugate a verb based on what letters a verb ends with. However, some verbs are irregular. Irregular verbs do not follow the normal pattern of conjugation. Instead, the forms must be learned differently. An example of an irregular verb in French is "être" (to be).
Every French noun has a gender. A noun can be either masculine or feminine.
The plural of a noun usually ends with -"s". For example, dog ("chien") becomes dogs ("chiens"). However, if a noun ends in -"au", -"eu", or -"ou", it can have -"x" at the end as a plural. For example, game ("jeu") becomes games ("jeux"). If a noun already ends with -"s", -"x", or -"z", it does not change in the plural.
In French, adjectives change in order to agree with the gender and number of the noun it describes.
The word order in French is subject-verb-object. In the sentence "Je mange le gâteau" (I eat the cake), "je" (I) is the subject and "le gâteau" (the cake) is the object. However, if the object is a pronoun, it goes before the verb. If "le gâteau" is replaced by "le" (it), the sentence becomes "Je le mange" (I eat it).
Stem (linguistics)
The stem of a verb is the main part of the verb to which the endings are added.
Qinhuangdao
Qinhuangdao (秦皇岛) is a city in the north of China. The name in Chinese means "island of the Qin Emperor" or "Emperor Qin's island", since it was where Emperor Qin Shi Huang sent men to search for immortals, or living beings who cannot die or grow old, across the sea. It is in Hebei Province. It is about east of Beijing, on the Bohai Sea. The city had 2,987,605 people as of 2010. Qinhuangdao is one of fourteen coastal open cities, which are important foreign trade ports in north China. It was approved as a national grade tourist city by the State Council. Famous scenic spots include Shanhaiguan and Beidaihe. Qinhuangdao City is a state-level economic and technological development zone of Qinhuangdao.