Oklahoma is a state located in the South Central United States. Oklahoma is the 20th-most extensive and the 28th-most populous of the 50 United States, the states name is derived from the Choctaw words okla and humma, meaning red people. The name was settled upon statehood, Oklahoma Territory and Indian Territory were merged, on November 16,1907, Oklahoma became the 46th state to enter the union. Its residents are known as Oklahomans, or informally Okies, and its capital, a major producer of natural gas and agricultural products, Oklahoma relies on an economic base of aviation, telecommunications, and biotechnology. In 2007, it had one of the economies in the United States, ranking among the top states in per capita income growth. Oklahoma City and Tulsa serve as Oklahomas primary economic anchors, with nearly two-thirds of Oklahomans living within their metropolitan statistical areas. With small mountain ranges, prairie and eastern forests, most of Oklahoma lies in the Great Plains, Cross Timbers, interior Highlands—a region especially prone to severe weather.
The name Oklahoma comes from the Choctaw phrase okla humma, literally meaning red people, equivalent to the English word Indian, okla humma was a phrase in the Choctaw language used to describe Native American people as a whole. Oklahoma became the de facto name for Oklahoma Territory, and it was approved in 1890. Oklahoma is the 20th-largest state in the United States, covering an area of 69,898 square miles and it is one of six states on the Frontier Strip and lies partly in the Great Plains near the geographical center of the 48 contiguous states. It is bounded on the east by Arkansas and Missouri, on the north by Kansas, on the northwest by Colorado, on the far west by New Mexico, much of its border with Texas lies along the Southern Oklahoma Aulacogen, a failed continental rift. The geologic figure defines the placement of the Red River, the Oklahoma panhandles Western edge is out of alignment with its Texas border. The Oklahoma/New Mexico border is actually 2.1 to 2.2 miles east of the Texas line, the border between Texas and New Mexico was set first as a result of a survey by Spain in 1819.
It was set along the 103rd Meridian, in the 1890s, when Oklahoma was formally surveyed using more accurate surveying equipment and techniques, it was discovered the Texas line was not set along the 103rd Meridian. Surveying techniques were not as accurate in 1819, and the actual 103rd Meridian was approximately 2.2 miles to the east and it was much easier to leave the mistake than for Texas to cede land to New Mexico to correct the surveying error. The placement of the Oklahoma/New Mexico border represents the true 103rd Meridian, cimarron County in Oklahomas panhandle is the only county in the United States that touches four other states, New Mexico, Texas and Kansas. Its highest and lowest points follow this trend, with its highest peak, Black Mesa, at 4,973 feet above sea level, situated near its far northwest corner in the Oklahoma Panhandle. The states lowest point is on the Little River near its far southeastern boundary near the town of Idabel, which dips to 289 feet above sea level
Pinctada is a genus of saltwater oysters, marine bivalve molluscs in the family Pteriidae, the pearl oysters. These oysters have an inner shell layer composed of nacre. Pearl oysters are not closely related to either the edible oysters of family Ostreidae or the pearl mussels of the families Unionidae and Margaritiferidae. P. margaritifera and P. maxima are used for culturing South Sea and they are cultured widely primarily in the central and eastern Indo-Pacific. A pearl oyster can be seen on the side of the 1. All species within the genus produce pearls, attempts have been made to harvest pearls commercially from many Pinctada species. Pearls are obtained in commercial quantities from some species of the related winged oyster genus Pteria. Pearls are produced from freshwater mussel species unrelated to pearl oysters and these freshwater species include Hyriopsis cumingii, Hyriopsis schlegelii, and a hybrid of the two species. At danger from the demand for pearls, the typical lifespan of a pearl oyster is usually around 3 years to 14 years.
Pinctada maxima are seeded at about 2 years of age and take 2 years to develop a pearl. They can be reseeded up to 3 or 4 times, akoya pearls are harvested after about 9 to 16 months. He analyzed historical records and used information about the biology of these and other species to explain its rapid disappearance
Shells of species within this class range from about 0.5 to 15 cm in length. Members of the order Dentaliida tend to be larger than those of the order Gadilida. These molluscs live in soft substrates offshore, molecular data suggest that the scaphopods are a sister group to the cephalopods, although higher-level molluscan phylogeny remains somewhat unresolved. The morphological shape of the body makes it difficult to orient it satisfactorily. As a result, researchers have disagreed as to which direction is anterior/ posterior. According to Shimek and Steiner, he apex of the shell and mantle are anatomically dorsal, the concave side of the shell and viscera are anatomically dorsal. The convex side has to be divided into ventral and dorsally posterior portions. Functionally, as in cephalopods, the aperture with the foot is anterior, the apical area posterior, the concave side dorsal. The shells of the members of the Gadilida are usually glassy-smooth in addition to being quite narrow and this along with other structures of their anatomy allows them to move with surprising speed through loose sediment to escape potential bottom-dwelling predators.
The Dentalids, on the hand, tend to have strongly ribbed. When they sense vibrations anywhere around them, their response is to freeze. This makes them harder to detect by animals such as ratfish which can sense the electrical signals given off by the most minute muscle movement, the mantle of a scaphopod is entirely within the shell. The foot extends from the end of the shell, and is used to burrow through the substrate. The scaphopod positions itself head down in the substrate, with the end of the shell projecting upward. This end seldom appears above the level of the substrate, most adult scaphopods live their lives entirely buried within the substrate. Water enters the cavity through the apical aperture, and is wafted along the body surface by cilia. There are no gills, the surface of the mantle cavity absorbs oxygen from the water. Unlike most other molluscs, there is no flow of water with a separate exhalant stream
Horseshoe crabs are marine arthropods of the family Limulidae and order Xiphosura or Xiphosurida. They are invertebrates meaning that they lack a spine, horseshoe crabs live primarily in and around shallow ocean waters on soft sandy or muddy bottoms. They occasionally come onto shore to mate and they are commonly used as bait and in fertilizer. In recent years, a decline in the population has occurred as a consequence of coastal destruction in Japan. Tetrodotoxin may be present in the roe of species inhabiting the waters of Thailand, because of their origin 450 million years ago, horseshoe crabs are considered living fossils. They belong to a separate subphylum and are related to arachnids. The earliest horseshoe crab fossils are found in strata from the late Ordovician period, the latter become functional just before the embryo hatches. Also, a pair of eyes is located near the mouth. The horseshoe crab has 5 additional eyes on top of its shell, the mouth is located in the center of the legs, whose bases are referred to as gnathobases and have the same function as jaws and help grind up food.
The horseshoe crab has five pairs of legs for walking, the long, rigid tail can be used to flip the animal over if turned upside down, so a horseshoe crab with a broken tail is susceptible to desiccation or predation. Behind its legs, the crab has book gills, which exchange respiratory gases. As in other arthropods, a true endoskeleton is absent, and they are more often found on the ocean floor searching for worms and molluscs, which are their main food. They may feed on crustaceans and even small fish, females are larger than males, C. rotundicauda is the size of a human hand, while L. polyphemus can be up to 60 cm long. The juveniles grow about 33% larger with every molt until reaching adult size, during the breeding season, horseshoe crabs migrate to shallow coastal waters. A male selects a female and clings to her back, several males surround the female and all fertilize together which makes it easy to spot and count females as they are the large center carapace surrounded by 3-5 smaller ones.
The female digs a hole in the sand and lays her eggs while the male fertilize them, the female can lay between 60,000 and 120,000 eggs in batches of a few thousand at a time. The eggs take about two weeks to hatch, shore birds eat many of them before they hatch, the larvae molt six times during the first year. Raising horseshoe crabs in captivity has proven to be difficult, some evidence indicates mating takes place only in the presence of the sand or mud in which the horseshoe crabs eggs were hatched
Silicon is a chemical element with symbol Si and atomic number 14. A hard and brittle crystalline solid with a metallic luster. It is a member of group 14 in the table, along with carbon above it and germanium, lead. It is not very reactive, although more reactive than germanium, Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure element in the Earths crust. It is most widely distributed in dusts, planetoids, over 90% of the Earths crust is composed of silicate minerals, making silicon the second most abundant element in the Earths crust after oxygen. Most silicon is used commercially without being separated, and often with little processing of the natural minerals, such use includes industrial construction with clays, silica sand, and stone. Silicate is used in Portland cement for mortar and stucco, and mixed with sand and gravel to make concrete for walkways, foundations. Silicates are used in whiteware ceramics such as porcelain, and in traditional quartz-based soda-lime glass, Silicon compounds such as silicon carbide are used as abrasives and components of high-strength ceramics.
Elemental silicon has an impact on the modern world economy. Most free silicon is used in the refining, aluminium-casting. Silicon is the basis of the widely used synthetic polymers called silicones, Silicon is an essential element in biology, although only tiny traces are required by animals. However, various sea sponges and microorganisms, such as diatoms and radiolaria, silica is deposited in many plant tissues, such as in the bark and wood of Chrysobalanaceae and the silica cells and silicified trichomes of Cannabis sativa and many grasses. Silicon is a solid at room temperature, with a point of 1,414 °C. Like water, it has a density in a liquid state than in a solid state and it expands when it freezes. With a relatively high conductivity of 149 W·m−1·K−1, silicon conducts heat well. In its crystalline form, pure silicon has a gray color, like germanium, silicon is rather strong, very brittle, and prone to chipping. Silicon, like carbon and germanium, crystallizes in a cubic crystal structure with a lattice spacing of 0.5430710 nm.
The outer electron orbital of silicon, like that of carbon, has four valence electrons, the 1s, 2s, 2p and 3s subshells are completely filled while the 3p subshell contains two electrons out of a possible six
Conch is a common name that is applied to a number of different medium to large-sized sea snails or their shells. The term generally applies to large snails whose shell has a high spire, in North America, a conch is often identified as a queen conch, found off the coast of Florida. Queen conches are valued for fish bait, and are known as seafood. The group of conchs that are referred to as true conchs are marine gastropod molluscs in the family Strombidae, specifically in the genus Strombus. For example, see Lobatus gigas, the conch, and Laevistrombus canarium. Many other species are often called conch, but are not at all closely related to the family Strombidae, including Melongena species. Species commonly referred to as conchs include the sacred chank or more correctly shankha shell, the English word conch is attested in Middle English, coming from Latin concha, which in turn comes from Greek konchē ultimately from PIE root *konkho-, cognate with Sanskrit śaṅkha. The meat of conchs is eaten raw in salads, or cooked, as in burgers, fritters, all parts of the conch meat are edible.
In The Bahamas, conch is served in fritter form, or as a raw. In the West Indies, local people eat conch in soups, restaurants all over the islands serve this particular meat. In the Dominican Republic and Haiti, conch is commonly eaten in curries or in a spicy soup and it is locally referred to as lambi. In The Turks and Caicos Islands, the Annual Conch Festival is held in November each year, local restaurateurs compete for the best and most original conch dishes, that are judged by international chefs. Free sampling of the dishes follows the judging, along with those festivities, other competitions and music performances occur well into the evening. In Puerto Rico, conch is served as a ceviche, often called ensalada de carrucho, consisting of raw conch marinated in lime juice, olive oil, garlic, green peppers and it is used to fill empanadas. In East Asian cuisines, this seafood is often cut into thin slices, Conch shells can be used as wind instruments. They are prepared by cutting a hole in the spire of the shell near the apex, sometimes a mouthpiece is used, but some shell trumpets are blown without one.
Many different kinds of mollusks can produce pearls, pearls from the queen conch, L. gigas, are rare and have been collectors items since Victorian times. In some gemological texts, non-nacreous gastropod pearls used to be referred to as calcareous concretions because they were porcellaneous, rather than nacreous, although non-nacreous, the surface of fine conch pearls has a unique and attractive appearance of its own
The individual components remain separate and distinct within the finished structure. The new material may be preferred for reasons, common examples include materials which are stronger, lighter. More recently, researchers have begun to actively include sensing, actuation and communication into composites. The most advanced examples perform routinely on spacecraft and aircraft in demanding environments, the earliest man-made composite materials were straw and mud combined to form bricks for building construction. Ancient brick-making was documented by Egyptian tomb paintings and daub is one of the oldest man-made composite materials, at over 6000 years old. Concrete is a material, and is used more than any other man-made material in the world. As of 2006, about 7.5 billion cubic metres of concrete are made each year—more than one metre for every person on Earth. 2181–2055 BC and was used for death masks Cob Mud Bricks, concrete was described by Vitruvius, writing around 25 BC in his Ten Books on Architecture, distinguished types of aggregate appropriate for the preparation of lime mortars.
For structural mortars, he recommended pozzolana, which were volcanic sands from the beds of Pozzuoli brownish-yellow-gray in colour near Naples. Natural cement-stones, after burning, produced cements used in concretes from post-Roman times into the 20th century, the glass fiber is relatively strong and stiff, whereas the polymer is ductile. Thus the resulting fiberglass is relatively stiff, flexible, concrete is the most common artificial composite material of all and typically consists of loose stones held with a matrix of cement. Concrete is a material, and will not compress or shatter even under quite a large compressive force. However, concrete cannot survive tensile loading, therefore, to give concrete the ability to resist being stretched, steel bars, which can resist high stretching forces, are often added to concrete to form reinforced concrete. Fibre-reinforced polymers or FRPs include carbon-fiber-reinforced polymer or CFRP, and glass-reinforced plastic or GRP, if classified by matrix there are thermoplastic composites, short fiber thermoplastics, long fibre thermoplastics or long fibre-reinforced thermoplastics.
There are numerous thermoset composites, including paper composite panels, many advanced thermoset polymer matrix systems usually incorporate aramid fibre and carbon fibre in an epoxy resin matrix. Shape memory polymer composites are high-performance composites, formulated using fibre or fabric reinforcement and they can be reheated and reshaped repeatedly without losing their material properties. These composites are ideal for such as lightweight, deployable structures, rapid manufacturing. Although high strain composites exhibit many similarities to shape memory polymers, Composites can use metal fibres reinforcing other metals, as in metal matrix composites or ceramic matrix composites, which includes bone and concrete
Aragonite is a carbonate mineral, one of the two most common, naturally occurring, crystal forms of calcium carbonate, CaCO3. It is formed by biological and physical processes, including precipitation from marine, aragonites crystal lattice differs from that of calcite, resulting in a different crystal shape, an orthorhombic crystal system with acicular crystal. Repeated twinning results in pseudo-hexagonal forms, Aragonite may be columnar or fibrous, occasionally in branching stalactitic forms called flos-ferri from their association with the ores at the Carinthian iron mines. The type location for aragonite is Molina de Aragón,25 km from Aragon for which it was named in 1797, an aragonite cave, the Ochtinská Aragonite Cave, is situated in Slovakia. In the US, aragonite in the form of stalactites and cave flowers is known from Carlsbad Caverns, massive deposits of oolitic aragonite sand are found on the seabed in the Bahamas. Aragonite is the high pressure polymorph of calcium carbonate, as such, it occurs in high pressure metamorphic rocks such as those formed at subduction zones.
Aragonite forms naturally in almost all mollusk shells, and as the calcareous endoskeleton of warm-, because the mineral deposition in mollusk shells is strongly biologically controlled, some crystal forms are distinctively different from those of inorganic aragonite. In some mollusks, the shell is aragonite, in others. The nacreous layer of the fossil shells of some extinct ammonites forms an iridescent material called ammolite. Aragonite forms in the ocean and in caves as inorganic precipitates called marine cements and speleothems, Aragonite is not uncommon in serpentinites where high Mg in pore solutions apparently inhibits calcite growth and promotes aragonite precipitation. Aragonite is metastable at the low pressures near the Earths surface and is commonly replaced by calcite in fossils. Aragonite older than the Carboniferous is essentially unknown and it can be synthesized by adding a calcium chloride solution to a sodium carbonate solution at temperatures above 60 °C or in water-ethanol mixtures at ambient temperatures.
Aragonite is thermodynamically unstable at temperature and pressure, and tends to alter to calcite on scales of 107 to 108 years. The mineral vaterite, known as μ-CaCO3, is another phase of calcium carbonate that is metastable at ambient conditions typical of Earths surface, in aquaria, aragonite is considered essential for the replication of reef conditions. Aragonite provides the necessary for much sea life and keeps the pH of the water close to its natural level. Aragonite has been tested for the removal of pollutants like zinc, cobalt. Aragonite sea Ikaite, CaCO3·6H2O Monohydrocalcite, CaCO3·H2O Nacre, otherwise known as Mother-of-Pearl Oolitic aragonite sand The Ochtinska aragonite cave Kosovo Caves Aragonite Formations
Epithelial is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of blood vessels and organs throughout the body, there are three principal shapes of epithelial cell, squamous and cuboidal. All glands are made up of epithelial cells, functions of epithelial cells include secretion, selective absorption, transcellular transport, and sensing. Epithelial layers contain no blood vessels, so they must receive nourishment via diffusion of substances from the connective tissue. Cell junctions are well-employed in epithelial tissues, in general, epithelial tissues are classified by the number of their layers and by the shape and function of the cells. The three principal shapes associated with epithelial cells are—squamous and columnar, squamous epithelium has cells that are wider than their height. Cuboidal epithelium has cells whose height and width are approximately the same, columnar epithelium has cells taller than they are wide.
However, when taller simple columnar epithelial cells are viewed in cross section showing several nuclei appearing at different heights and this kind of epithelium is therefore described as pseudostratified columnar epithelium. Transitional epithelium has cells that can change from squamous to cuboidal, Simple epithelium is a single layer of cells with every cell in direct contact with the basement membrane that separates it from the underlying connective tissue. In general, it is found where absorption and filtration occur, the thinness of the epithelial barrier facilitates these processes. In general, simple epithelial tissues are classified by the shape of their cells, the four major classes of simple epithelium are, simple squamous, simple cuboidal, simple columnar, pseudostratified. Simple squamous, which is found lining areas where passive diffusion of gases occur, E. g. skin, walls of capillaries, linings of the pericardial and peritoneal cavities, as well as the linings of the alveoli of the lungs.
Simple cuboidal, these cells may have secretory, absorptive, or excretory functions, examples include small collecting ducts of kidney and salivary gland. Simple columnar, cells can be secretory, absorptive, or excretory, Simple columnar epithelium can be ciliated or non-ciliated, ciliated columnar is found in the reproductive tract. Non-ciliated epithelium can possess microvilli, pseudostratified columnar epithelium, can be ciliated or non-ciliated. The ciliated type is called respiratory epithelium as it is almost exclusively confined to the larger respiratory airways of the nasal cavity, trachea. Stratified epithelium differs from simple epithelium in that it is multilayered and it is therefore found where body linings have to withstand mechanical or chemical insult such that layers can be abraded and lost without exposing subepithelial layers. Cells flatten as the layers become more apical, though in their most basal layers the cells can be squamous, stratified epithelia can have the following specializations, The basic cell types are squamous and columnar classed by their shape
Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by insect larvae to form cocoons. The best-known silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity, Silk is produced by several insects, but generally only the silk of moth caterpillars has been used for textile manufacturing. There has been research into other types of silk, which differ at the molecular level. Silk is mainly produced by the larvae of insects undergoing complete metamorphosis, Silk production occurs in Hymenoptera, mayflies, leafhoppers, lacewings, fleas and midges. Other types of arthropod produce silk, most notably various arachnids such as spiders, the word silk comes from Old English sioloc, from Greek σηρικός serikos, ultimately from an Asian source. Several kinds of silk, which are produced by caterpillars other than the mulberry silkworm, have been known and used in China, South Asia.
However, the scale of production was far smaller than for cultivated silks. Thus, the way to obtain silk suitable for spinning into textiles in areas where commercial silks are not cultivated was by tedious. Commercial silks originate from reared silkworm pupae, which are bred to produce a silk thread with no mineral on the surface. The pupae are killed by either dipping them in boiling water before the adult moths emerge or by piercing them with a needle. These factors all contribute to the ability of the cocoon to be unravelled as one continuous thread. Wild silks tend to be difficult to dye than silk from the cultivated silkworm. Genetic modification of domesticated silkworms is used to facilitate the production of more types of silk. Silk fabric was first developed in ancient China, the earliest example of silk fabric is from 3630 BC, and it was used as wrapping for the body of a child from a Yangshao culture site in Qingtaicun at Xingyang, Henan. Legend gives credit for developing silk to a Chinese empress, because of its texture and lustre, silk rapidly became a popular luxury fabric in the many areas accessible to Chinese merchants.
Silk was in demand, and became a staple of pre-industrial international trade. In July 2007, archaeologists discovered intricately woven and dyed silk textiles in a tomb in Jiangxi province, Silk is described in a chapter on mulberry planting by Si Shengzhi of the Western Han
Structural coloration is the production of colour by microscopically structured surfaces fine enough to interfere with visible light, sometimes in combination with pigments. For example, peacock feathers are pigmented brown, but their microscopic structure makes them reflect blue and green light. Structural coloration was first observed by English scientists Robert Hooke and Isaac Newton, Young described iridescence as the result of interference between reflections from two or more surfaces of thin films, combined with refraction as light enters and leaves such films. The geometry determines that at certain angles, the light reflected from both surfaces interferes constructively, while at other angles, the light interferes destructively, different colours therefore appear at different angles. Some cuts of meat show structural coloration due to the exposure of the arrangement of the muscular fibres. Many of these photonic mechanisms correspond to elaborate structures visible by electron microscopy, in plants, brilliant colours are produced by structures within cells.
In his 1704 book Opticks, Isaac Newton described the mechanism of the other than the brown pigment of peacock tail feathers. Thomas Young extended Newtons particle theory of light by showing that light could behave as a wave. He showed in 1803 that light could diffract from sharp edges or slits, Colours of the latter kind are often spoken of as structural colours, they are caused by the structure of the coloured surfaces. The metallic lustre of the feathers of birds, such as the humming birds, is due to the presence of excessively fine striae upon the surface of the feathers. Structural coloration is caused by interference effects rather than by pigments, Colours are produced when a material is scored with fine parallel lines, formed of one or more parallel thin layers, or otherwise composed of microstructures on the scale of the colours wavelength. Structural coloration is responsible for the blues and greens of the feathers of birds, as well as many butterfly wings. These are often iridescent, as in peacock feathers and nacreous shells such as of pearl oysters and this is because the reflected colour depends on the viewing angle, which in turn governs the apparent spacing of the structures responsible.
Structural colours can be combined with pigment colours, peacock feathers are pigmented brown with melanin, iridescence, as explained by Thomas Young in 1803, is created when extremely thin films reflect part of the light falling on them from their top surfaces. The rest of the light goes through the films, and a part of it is reflected from their bottom surfaces. The two sets of reflected waves travel back upwards in the same direction, when the waves are one or more whole wavelength apart – in other words at certain specific angles, they add, giving a strong reflection. At other angles and phase differences, they can subtract, giving weak reflections, the thin film therefore selectively reflects just one wavelength – a pure colour – at any given angle, but other wavelengths – different colours – at different angles. So, as a structure like a butterflys wing or birds feather moves
Nautiloids are a large and diverse group of marine cephalopods belonging to the subclass Nautiloidea that began in the Late Cambrian and are represented today by the living Nautilus and Allonautilus. Nautiloids flourished during the early Paleozoic era, where they constituted the main predatory animals, some 2,500 species of fossil nautiloids are known, but only a handful of species survive to the present day. Nautiloids are among the group of known as cephalopods, an advanced class of mollusks which includes ammonoids and modern coleoids such as octopus. Other mollusks include gastropods and bivalves, the most common classification of the cephalopods has been a four-fold division, into the Orthoceratoids, nautiloids and coleoids. This article is about nautiloids in that sense, sometimes called Nautiloidea sensu lato. Cladistically speaking, nautiloids are a paraphyletic assemblage united by shared primitive features not found in derived cephalopods. In other words, they are a group that is thought to have given rise to Orthoceratoids and coleoids.
Both ammonoids and coleoids have traditionally assumed to have descended from bactritids. The ammonoids are extinct cousins of the nautiloids that evolved early in the Devonian period, some workers apply the name Nautiloidea to a more exclusive group, called Nautiloidea sensu stricto. This taxon consists only of those orders that are related to the modern nautilus. The membership assigned varies somewhat from author to author, but usually includes Tarphycerida, the septa between the chambers of the phragmocone are formed during growth spurts of the animal. At that time the rear of the mantle secretes a new septum adding another chamber while the forward part adds onto the shell. The body of the animal, its viscera, continues to occupy the last chamber of the shell – the living chamber, the septa are perforated by the siphuncle, which runs through each of the internal chambers of the shell. Surrounding the fleshy tube of the siphuncle are structures made of aragonite, septal necks, some of the earlier nautiloids deposited calcium carbonate in the empty chambers or within the siphuncle, a process which may have been connected with controlling buoyancy.
The nature of the siphuncle and its position within the shell are important in classifying nautiloids, sutures are visible as a series of narrow wavy lines on the surface of the shell, and they appear where each septum contacts the wall of the outer shell. The sutures of the nautiloids are simple in shape, being either straight or slightly curved and this is different from the zigzag sutures of the goniatites and the highly complex sutures of the ammonites. It is not usually found in less than 100 meters deep. Nautili are free swimming animals that possess a head with two simple eyes and arms