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Ditropisena
Assimineidae is a family of small snails, also known as palmleaf snails, with an operculum, gastropod mollusks or micromollusks in the superfamily Truncatelloidea. Many of these very small snails live in intermediate habitats, being amphibious between saltwater and land; others live in freshwater. Distribution The distribution of the Assimineidae is worldwide."Family summary for Assimineidae" , last change 15-08-2006, accessed 4 August 2010. The oldest fossils are known from the Cenomanian aged |
Gastropod Shell
The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, tracum, is typically made of calcium carbonate precipitated into an organic matrix known as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burmese Amber
Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. The amber is of significant palaeontological interest due to the diversity of flora and fauna contained as inclusions, particularly arthropods including insects and arachnids but also birds, lizards, snakes, frogs and fragmentary dinosaur remains. The amber has been known and commercially exploited since the first century AD, and has been known to science since the mid-nineteenth century. Research on the deposit has attracted controversy due to its alleged role in funding internal conflict in Myanmar and hazardous working conditions in the mines where it is collected. Geological context, depositional environment and age The amber is found within the Hukawng Basin, a large Cretaceous- Cenozoic sedimentary basin within northern Myanmar. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assiminea
''Assiminea'' is a genus of minute, salt-tolerant snails with an operculum, aquatic gastropod mollusks, or micromollusks, in the family Assimineidae.Bouchet, P.; Gofas, S. (2015). Assiminea Fleming, 1828. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=137681 on 2015-04-29 Distribution and habitat These snails can be found worldwide. They live usually in brackish water and salt marshes of tropical and temperate regions, at beaches, in water and at land. Description These are very small to medium large snails, between 2 and 13 mm). Some adults do not exceed a size of 3 mm. The shape of the thin shells is somewhat ovately conical. The margin of the aperture is simple. The operculum is in most cases horny. The eyes are at the end of short, stout stalks. They feed on vegetable detritus and small algae. They lay their eggs in the mud, and hatch as free-swimming larvae. Species According to the World Register o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angustassiminea
''Angustassiminea'' is a genus of gastropods belonging to the family Assimineidae. Species The species of this genus are found in Japan and Northern America. The following species are recognised in the genus ''Angustassiminea'': *''Angustassiminea andrewsiana'' *''Angustassiminea californica'' (synonym: ''Assiminea californica'' (Tryon, 1865)) *''Angustassiminea castanea'' *''Angustassiminea infima'' *''Angustassiminea kyushuensis'' *''Angustassiminea lucida'' *''Angustassiminea nitida'' *''Angustassiminea satumana'' *''Angustassiminea succinea'' *''Angustassiminea vulgaris'' ;Species brought into synonymy: * ''Angustassiminea yoshidayukioi'' (Kuroda, 1959): synonym of ''Assiminea yoshidayukioi ''Assiminea'' is a genus of minute, salt-tolerant snails with an operculum, aquatic gastropod mollusks, or micromollusks, in the family Assimineidae.Bouchet, P.; Gofas, S. (2015). Assiminea Fleming, 1828. Accessed through: World Register of Mar ...'' Kuroda, 1959 References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy Of The Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised in 2005 by Philippe Bouchet and Jean-Pierre Rocroi is a system for the scientific classification of gastropod mollusks. (Gastropods are a taxonomic class of animals which consists of snails and slugs of every kind, from the land, from freshwater, and from saltwater.) The paper setting out this taxonomy was published in the journal '' Malacologia''. The system encompasses both living and extinct groups, as well as some fossils whose classification as gastropods is uncertain. The Bouchet & Rocroi system was the first complete gastropod taxonomy that primarily employed the concept of clades, and was derived from research on molecular phylogenetics; in this context a clade is a "natural grouping" of organisms based upon a statistical cluster analysis. In contrast, most of the previous overall taxonomic schemes for gastropods relied on morphological features to classify these animals, and used taxon ranks such as order, superorder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subfamily
In biological classification, a subfamily ( Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoological names with "-inae". See also * International Code of Nomenclature for algae, fungi, and plants The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ... * International Code of Zoological Nomenclature * Rank (botany) * Rank (zoology) Sources {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenidium (mollusc)
A ctenidium is a respiratory organ or gill which is found in many molluscs. This structure exists in bivalves, cephalopods, Polyplacophorans (chitons), and in aquatic gastropods such as freshwater snails and marine snails. Some aquatic gastropods possess one ctenidium known as monopectinate and others have a pair of ctenidia known as bipectinate. A ctenidium is shaped like a comb or a feather, with a central part from which many filaments or plate-like structures protrude, lined up in a row. It hangs into the mantle cavity and increases the area available for gas exchange. The apple snail. Retrieved 2012-04-20. The word is Latinized but is derived from the ''ktenidion'' which means ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snout
A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, rostrum, or proboscis. The wet furless surface around the nostrils of the nose of many mammals is called the rhinarium (colloquially this is the "cold wet snout" of some mammals). The rhinarium is often associated with a stronger sense of olfaction. Variation Snouts are found on many mammals in a variety of shapes. Some animals, including ursines and great cats, have box-like snouts, while others, like shrews, have pointed snouts. Pig snouts are flat and cylindrical. Primates Strepsirrhine primates have muzzles, as do baboons. Great apes have reduced muzzles, with the exception being human beings, whose face does not have protruding jaws nor a snout but merely a human nose. Dogs The muzzle begins at the stop, just below the eyes, and includes the dog's nose and mouth. In the domestic dog, most of the upper muzzle contains org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tentacles
In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work mainly like muscular hydrostats. Most forms of tentacles are used for grasping and feeding. Many are sensory organs, variously receptive to touch, vision, or to the smell or taste of particular foods or threats. Examples of such tentacles are the eyestalks of various kinds of snails. Some kinds of tentacles have both sensory and manipulatory functions. A tentacle is similar to a cirrus, but a cirrus is an organ that usually lacks the tentacle's strength, size, flexibility, or sensitivity. A nautilus has cirri, but a squid has tentacles. Invertebrates Molluscs Many molluscs have tentacles of one form or another. The most familiar are those of the pulmonate land snails, which usually have two sets of tentacles on the head: when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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