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Allonautilus Perforatus
''Allonautilus perforatus'' also known as the Bali chambered nautilus, is a species of nautilus native to the waters around Bali, Indonesia. It is known only from drifted shells and, as such, is the least studied of the six recognized nautilus species. Thus, not much is known about it outside of the shell. Habitat and Distribution The nautilus is reported to live on the coastal reefs of Baliand Papua New Guinea. They have been reported to live in nearby deep-water habitats as well. Ultimately little is known about the exact distribution of ''A. perforatus'' compared with the more abundant relatives such as '' A. scrobiculatus.'' Shells of the nautilus are sold in Balinese market placesWard, P.D. & W.B. Saunders 1997''Allonautilus'': a new genus of living nautiloid cephalopod and its bearing on phylogeny of the Nautilida ''Journal of Paleontology'' 71(6): 1054–1064. and tend to be less common. Reports from these markers detail that the shells have notable ''Octopus'' boring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timothy Abbott Conrad
Timothy Abbott Conrad (June 21, 1803 in Trenton, New Jersey – August 9, 1877 in Trenton) was an American geologist and malacologist. Biography He was from early life an investigator of American paleontology and natural history, devoting himself to the study of the shells of the Tertiary and Cretaceous formations, and to existing species of mollusks. In 1831 he began the issue of a work on “American Marine Conchology,” and the year following published the first number of his “Fossil Shells of the Tertiary Formation,” which was never completed. A “Monography of the Family Unionidae” was issued between 1835 and 1847. The lithographed plates in his publications were in part his own work. He contributed many articles to the '' American Journal of Science'' and the ''Journal of the Philadelphia Academy of Science''. As one of the New York state geologists he prepared the geological report for 1837. He was paleontologist of the New York Geological Survey from 1838 until ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bali
Bali () is a province of Indonesia and the westernmost of the Lesser Sunda Islands. East of Java and west of Lombok, the province includes the island of Bali and a few smaller neighbouring islands, notably Nusa Penida, Nusa Lembongan, and Nusa Ceningan to the southeast. The provincial capital, Denpasar, is the most populous city in the Lesser Sunda Islands and the second-largest, after Makassar, in Eastern Indonesia. The upland town of Ubud in Greater Denpasar is considered Bali's cultural centre. The province is Indonesia's main tourist destination, with a significant rise in tourism since the 1980s. Tourism-related business makes up 80% of its economy. Bali is the only Hindu-majority province in Indonesia, with 86.9% of the population adhering to Balinese Hinduism. It is renowned for its highly developed arts, including traditional and modern dance, sculpture, painting, leather, metalworking, and music. The Indonesian International Film Festival is held every year in Bal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautilus
The nautilus (, ) is a pelagic marine mollusc of the cephalopod family Nautilidae. The nautilus is the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina. It comprises six living species in two genera, the type of which is the genus ''Nautilus''. Though it more specifically refers to species ''Nautilus pompilius'', the name chambered nautilus is also used for any of the Nautilidae. All are protected under CITES Appendix II. Depending on species, adult shell diameter is between 4 and 10 inches. Nautilidae, both extant and extinct, are characterized by involute or more or less convolute shells that are generally smooth, with compressed or depressed whorl sections, straight to sinuous sutures, and a tubular, generally central siphuncle.Kümmel, B. 1964. Nautiloidae-Nautilida, in the Treatise on Invertebrate Paleontology, Geological Society of America and Univ of Kansas Press, Teichert and Moore eds. Having survived relatively u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea. Indonesia is the world's largest archipelagic state and the 14th-largest country by area, at . With over 275 million people, Indonesia is the world's fourth-most populous country and the most populous Muslim-majority country. Java, the world's most populous island, is home to more than half of the country's population. Indonesia is a presidential republic with an elected legislature. It has 38 provinces, of which nine have special status. The country's capital, Jakarta, is the world's second-most populous urban area. Indonesia shares land borders with Papua New Guinea, East Timor, and the eastern part of Malaysia, as well as maritime borders with Singapore, Vietnam, Thailand, the Philippines, Australia, Palau, and India ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papua New Guinea
Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country in Oceania that comprises the eastern half of the island of New Guinea and its offshore islands in Melanesia (a region of the southwestern Pacific Ocean north of Australia). Its capital, located along its southeastern coast, is Port Moresby. The country is the world's third largest island country, with an area of . At the national level, after being ruled by three external powers since 1884, including nearly 60 years of Australian administration starting during World War I, Papua New Guinea established its sovereignty in 1975. It became an independent Commonwealth realm in 1975 with Elizabeth II as its queen. It also became a member of the Commonwealth of Nations in its own right. There are 839 known languages of Papua New Guinea, one of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allonautilus Scrobiculatus
''Allonautilus scrobiculatus'', also known as the crusty nautilus or fuzzy nautilus, is a species of nautilus native to the waters around New Guinea, specifically New Britain and Milne Bay, and the Solomon Islands. ''A. scrobiculatus'' is recognizable by the large open umbilicus, which is around 20% of the shell diameter at its widest point. This species, along with the closely related '' A. perforatus'', were originally placed in the genus ''Nautilus'', but have recently been given their own genus on account of significant morphological differences.Ward, P.D. & W.B. Saunders 1997''Allonautilus'': a new genus of living nautiloid cephalopod and its bearing on phylogeny of the Nautilida ''Journal of Paleontology'' 71(6): 1054–1064. The most obvious are features of the shell, including crease and an encrusting layer ( periostracum) that covers most of the shell. Gills and reproductive structures also differ significantly from members of the genus ''Nautilus''. The shell is usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopus
An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other cephalopods, an octopus is bilaterally symmetric with two eyes and a beaked mouth at the center point of the eight limbs. The soft body can radically alter its shape, enabling octopuses to squeeze through small gaps. They trail their eight appendages behind them as they swim. The siphon is used both for respiration and for locomotion, by expelling a jet of water. Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse of all invertebrates. Octopuses inhabit various regions of the ocean, including coral reefs, pelagic waters, and the seabed; some live in the intertidal zone and others at abyssal depths. Most species grow quickly, mature ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbilicus (mollusk)
The umbilicus of a shell is the axially aligned, hollow cone-shaped space within the whorls of a coiled mollusc shell. The term umbilicus is often used in descriptions of gastropod shells, i.e. it is a feature present on the ventral (or under) side of many (but not all) snail shells, including some species of sea snails, land snails, and freshwater snails. The word is also applied to the depressed central area on the planispiral coiled shells of ''Nautilus'' species and fossil ammonites. (These are not gastropods, but shelled cephalopods.) In gastropods The spirally coiled whorls of gastropod shells frequently connect to each other by their inner sides, during the natural course of its formation. This results in a more or less solid central axial pillar, known as the columella. The more intimate the contact between the concave side of the whorls is, the more solid the columella becomes. On the other hand, if this connection is less intense, a hollow space inside the whorls may re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periostracum
The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and bivalves, but it is also found in cephalopods such as ''Allonautilus scrobiculatus''. The periostracum is an integral part of the shell, and it forms as the shell forms, along with the other shell layers. The periostracum is used to protect the organism from corrosion. The periostracum is visible as the outer layer of the shell of many molluscan species from terrestrial, freshwater, and marine habitats, and may be seen in land snails, river mussels, and other kinds of freshwater bivalves, as well as in many kinds of marine shelled molluscs. The word ''periostracum'' means "around the shell", meaning that the periostracum is wrapped around what is usually the more calcareous part of the shell. Technically, the calcareous part of the shel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
