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Spine (zoology)
In a zoological context, spines are hard, needle-like anatomical structures found in both vertebrate and invertebrate species. The spines of most spiny mammals are modified hairs, with a spongy center covered in a thick, hard layer of keratin and a sharp, sometimes barbed tip. Occurrence Mammals Spines in mammals include the prickles of hedgehogs and among rodents, the quills of both New World and Old World porcupines as well as the prickly fur of spiny mice, spiny pocket mice and spiny rats. They are also found on afrotherian tenrecs, marsupial spiny bandicoots and on echidnas, of the monotremes. An ancient synapsid, ''Dimetrodon'', had extremely long spines on its backbone that were joined together with a web of skin that formed a sail-like structure. Many mammalian species, like cats and fossas, also have penile spines. The Mesozoic eutriconodont mammal '' Spinolestes'' already displayed spines similar to those of modern spiny mice. Fish Spines are found in the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * jawless fish, which include hagfish and lampreys * jawed vertebrates, which include: ** cartilaginous fish (sharks, rays, and ratfish) ** bony vertebrates, which include: *** ray-fins (the majority of living bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant vertebrates range in size from the frog species ''Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described animal species; the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, which do not hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimetrodon
''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontidae. The most prominent feature of ''Dimetrodon'' is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It walked on four legs and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the Southwestern United States, the majority coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, its fossils have been found in Germany. Over a dozen species have been named since the genus was first erected in 1878. ''Dimetrodon'' is often mistaken for a dinosaur or as a contemporary of dinosaurs in popular culture, but it became extinct some 40 million years before the first appearance of dinosaurs. Rept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copulatory
Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetration for sexual pleasure or sexual reproduction; dictionary sources state that it especially means this, and scholarly sources over the years agree. See, for example; * * * * * * * * * This is also known as vaginal intercourse or vaginal sex. Other forms of penetrative sexual intercourse include anal sex (penetration of the anus by the penis), oral sex (penetration of the mouth by the penis or oral penetration of the female genitalia), fingering (sexual penetration by the fingers) and penetration by use of a dildo (especially a strap-on dildo). These activities involve physical intimacy between two or more individuals and are usually used among humans solely for physical or emotional pleasure and can contribute to human bonding. There a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitar Lupanaria
''Hysteroconcha lupanaria'' is a species of marine bivalve mollusc in the family Veneridae The Veneridae or venerids, common name: Venus clams, are a very large family of minute to large, saltwater clams, marine bivalve molluscs. Over 500 living species of venerid bivalves are known, most of which are edible, and many of which are ex ..., the Venus clams.MolluscaBase eds. (2022). MolluscaBase. Hysteroconcha lupanaria (Lesson, 1831). Accessed through: World Register of Marine Species at: https://marinespecies.org/aphia.php?p=taxdetails&id=507708 on 2022-01-20 Description The shell of this species is unusual in that it has a double series of long, curved spines on the posterior slope of each valve. A closely related species which occurs in the Western Atlantic is '' Pitar dione''. Distribution This species is found in the Eastern Pacific Ocean. References * Huber, M. (2010). Compendium of bivalves. A full-color guide to 3,300 of the world's marine bivalves. A status on Biva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of marine and freshwater Mollusca, molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. They include the clams, oysters, Cockle (bivalve), cockles, mussels, scallops, and numerous other family (biology), families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into Ctenidium (mollusc), ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can nekton, swim. The shipworms bore into wood, clay, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod
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. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusc Shell
The mollusc (or molluskOften spelled mollusk shell in the USA; the spelling "mollusc" are preferred by ) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which includes snails, clams, tusk shells, and several other classes. Not all shelled molluscs live in the sea; many live on the land and in freshwater. The ancestral mollusc is thought to have had a shell, but this has subsequently been lost or reduced on some families, such as the squid, octopus, and some smaller groups such as the caudofoveata and solenogastres. Today, over 100,000 living species bear a shell; there is some dispute as to whether these shell-bearing molluscs form a monophyletic group (conchifera) or whether shell-less molluscs are interleaved into their family tree. Malacology, the scientific study of molluscs as living organisms, has a branch devoted to the study of shells, and this is called conchology—although ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Urchin
Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of sea urchins are round and spiny, ranging in diameter from . Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines. Although algae are the primary diet, sea urchins also eat slow-moving ( sessile) animals. Predators that eat sea urchins include a wide variety of fish, starfish, crabs, marine mammals. Sea urchins are also used as food especially in Japan. Adult sea urchins have fivefold symmetry, but their pluteus larvae feature bilateral (mirror) symmetry, indicating that the sea urchin belongs to the Bilateria group of animal phyla, which also comprises the chordates and the arthropods, the annelids and the molluscs, and are found in every ocean and in every climate, from the tropics to the po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal
A journal, from the Old French ''journal'' (meaning "daily"), may refer to: *Bullet journal, a method of personal organization *Diary, a record of what happened over the course of a day or other period *Daybook, also known as a general journal, a daily record of financial transactions *Logbook, a record of events important to the operation of a vehicle, facility, or otherwise *Record (other) *Transaction log, a chronological record of data processing * Travel journal In publishing, ''journal'' can refer to various periodicals or serials: *Academic journal, an academic or scholarly periodical **Scientific journal, an academic journal focusing on science **Medical journal, an academic journal focusing on medicine **Law review, a professional journal focusing on legal interpretation *Magazine, non-academic or scholarly periodicals in general **Trade magazine, a magazine of interest to those of a particular profession or trade **Literary magazine, a magazine devoted to litera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stingray
Stingrays are a group of sea rays, which are cartilaginous fish related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae (deepwater stingray), Urolophidae (stingarees), Urotrygonidae (round rays), Dasyatidae (whiptail stingrays), Potamotrygonidae (river stingrays), Gymnuridae (butterfly rays) and Myliobatidae (eagle rays). There are about 220 known stingray species organized into 29 genera. Stingrays are common in coastal tropical and subtropical marine waters throughout the world. Some species, such as the thorntail stingray (''Dasyatis thetidis''), are found in warmer temperate oceans and others, such as the deepwater stingray (''Plesiobatis daviesi''), are found in the deep ocean. The river stingrays and a number of whiptail stingrays (such as the Niger stingray (''Fontitrygon garouaensis'')) are restricted to fresh water. Most myliobatoids are dem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scorpion Fish
The Scorpaenidae (also known as scorpionfish) are a family of mostly marine fish that includes many of the world's most venomous species. As their name suggests, scorpionfish have a type of "sting" in the form of sharp spines coated with venomous mucus. The family is a large one, with hundreds of members. They are widespread in tropical and temperate seas but mostly found in the Indo-Pacific. They should not be confused with the cabezones, of the genus '' Scorpaenichthys'', which belong to a separate, though related, family, Cottidae. Taxonomy Scorpaenidae was described as a family in 1826 by the French naturalist Antoine Risso. The family is included in the suborder Scorpaenoidei of the order Scorpaeniformes in the 5th Edition of ''Fishes of the World'' but other authorities place it in the Perciformes either in the suborder Scorpaenoidei or the superfamily Scorpaenoidea. The subfamilies of this family are treated as valid families by some authorities. Subfamilies and tribes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinolestes
''Spinolestes'' is an extinct mammal genus from the Early Cretaceous of Spain. A gobiconodontid eutriconodont, it is notable for the remarkable degree of preservation, offering profound insights to the biology of non-therian mammals.Thomas Martin, Jesús Marugán-Lobón, Romain Vullo, Hugo Martín-Abad, Zhe-Xi Luo & Angela D. Buscalioni (2015). A Cretaceous eutriconodont and integument evolution in early mammals. Nature 526, 380–384. doi:10.1038/nature14905 Description ''Spinolestes holotype, MCCMLH30000A', hails from Las Hoyas, Spain. The living animal was about 24 centimeters long and weighted somewhere between 50 and 70 grams. As a Konservat-Lagerstätten specimen, it is famous for being remarkably well preserved, including not only the skeleton but also multiple soft tissues like fur, skin, internal organs and ears (both external and internal), a rarity among Mesozoic mammals. Besides soft-tissues, ''Spinolestes'' is also remarkable for its xenarthrous vertebrae, converge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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