Insects have a range of mouthparts, adapted to particular modes of feeding. The earliest insects had chewing mouthparts. Specialization has been for piercing and sucking, although a range of specializations exist, as these modes of feeding have evolved a number of times. In this page, the individual mouthparts are introduced for chewing insects. Specializations are described thereafter. Like most external features of arthropods, the mouthparts of hexapoda are derived. Insect mouthparts show a multitude of different functional mechanisms across the wide diversity of species considered insects, it is common for significant homology to be conserved, with matching structures formed from matching primordia, having the same evolutionary origin. On the other hand structures that physically are identical, share identical functionality as well, may not be homologous. Examples of chewing insects include dragonflies and beetles; some insects do not have chewing mouthparts as adults but do chew solid food when they feed while they still are larvae.
The moths and butterflies are major examples of such adaptations. A chewing insect has a pair of one on each side of the head; the mandibles are caudal to the anterior to the maxillae. The mandibles are the largest and most robust mouthparts of a chewing insect, it uses them to masticate food items. Two sets of muscles move the mandibles in the coronal plane: abductor muscles move insects' mandibles apart; this they do in opening and closing their jaws in feeding, but in using the mandibles as tools, or in fighting. In carnivorous chewing insects, the mandibles are serrated and knife-like, with piercing points. In herbivorous chewing insects mandibles tend to be broader and flatter on their opposing faces, as for example in caterpillars. In males of some species, such as of Lucanidae and some Cerambycidae, the mandibles are modified to such an extent that they do not serve any feeding function, but are instead used to defend mating sites from other males. In some ants and termites, the mandibles serve a defensive function.
In bull ants, the mandibles are toothed, used both as hunting appendages. In bees, that feed by use of a proboscis, the primary use of the mandibles is to manipulate and shape wax, many paper wasps have mandibles adapted to scraping and ingesting wood fibres. Situated beneath the mandibles, paired maxillae manipulate and, in chewing insects masticate, food; each maxilla consists of two parts, the proximal cardo, distal stipes. At the apex of each stipes are two lobes, the inner lacinia and outer galea. At the outer margin, the typical galea is a cupped or scoop-like structure, located over the outer edge of the labium. In non-chewing insects, such as adult Lepidoptera, the maxillae may be drastically adapted to other functions. Unlike the mandibles, but like the labium, the maxillae bear lateral palps on their stipites; these palps serve as organs of touch and taste in feeding, in inspection of potential foods. In chewing insects and abductor muscles extend from inside the cranium to within the bases of the stipites and cardines much as happens with the mandibles in feeding, in using the maxillae as tools.
To some extent the maxillae are more mobile than the mandibles, the galeae and palps can move up and down somewhat, in the sagittal plane, both in feeding and in working, for example in nest building by mud-dauber wasps. Maxillae in most insects function like mandibles in feeding, but they are more mobile and less sclerotised than mandibles, so they are more important in manipulating soft, liquid, or particulate food rather than cutting or crushing food such as material that requires the mandibles to cut or crush. Like the mandibles, maxillae are innervated by the sub-esopharyngeal ganglia; the labium is a quadrilateral structure, formed by paired, fused secondary maxillae. It is the major component of the floor of the mouth. Together with the maxillae, the labrum assists manipulation of food during mastication; the role of the labium in some insects however, is adapted to special functions. In these insects, the labium folds neatly beneath the head and thorax, but the insect can flick it out to snatch prey, inject venom to kill and digest the prey, to bear it back to the head, where the chewing mouthparts can demolish it and swallow the particles.
The labium is attached at the rear end of the structure called cibarium, its broad basal portion is divided into regions called the submentum, the proximal part, the mentum in the middle, the prementum, the distal section, furthest anterior. The prementum bears; these structures are homologous to the galea of maxillae. The labial palps borne on the sides of labium are the counterparts of maxillary pal
The proboscis monkey or long-nosed monkey, known as the bekantan in Indonesia, is a reddish-brown arboreal Old World monkey with an unusually large nose. It is endemic to the southeast Asian island of Borneo; this species co-exists with the Bornean orangutan. It belongs in the monotypic genus Nasalis. Proboscis monkeys belong to the subfamily Colobinae of the Old World monkeys; the two subspecies are: N. l. larvatus, which occupies the whole range of the species N. l. orientalis, restricted to north-east KalimantanHowever, the difference between the subspecies is small, not all authorities recognise N. l. orientalis. The proboscis monkey is a large species. Only the Tibetan macaque and a few of the gray langurs can rival its size. Sexual dimorphism is pronounced in the species. Males have a head-body length of 66 to 76.2 cm and weigh 16 to 22.5 kg, with a maximum known weight of 30 kg. Females measure 53.3 to 62 cm in head-and-body length and weigh 7 to 12 kg, with a maximum known mass of 15 kg.
Further adding to the dimorphism is the large nose or proboscis of the male, which can exceed 10.2 cm in length, hangs lower than the mouth. Theories for the extensive length of their nose suggest it may be sexual selection by the females, who prefer louder vocalisations, with the size of the nose increasing the volume of the call; the nose of the female is still large for a primate. The proboscis monkey has a long coat; the underfur is yellowish, or greyish to light-orange. Infants are born with a blue coloured face. By 8.5 months of age, the face has become cream coloured like the adults. The male has a red penis with a black scrotum. Both sexes have bulging stomachs. Many of the monkeys' toes are webbed. Proboscis monkeys live in groups composed of one adult male, some adult females and their offspring. All-male groups may exist; some individuals are solitary males. Monkey groups live in overlapping home ranges, with little territoriality, in a fission-fusion society, with groups gathering at sleeping sites as night falls.
There exist bands which arise when groups come together and slip apart yet sometimes groups may join to mate and groom. Groups gather during the day and travel together, but individuals only groom and play with those in their own group. One-male groups consist of 9 -- 19 individuals. One-male groups consist of three to 12 individuals, but can contain more. Serious aggression is uncommon among the monkeys but minor aggression does occur. Overall, members of the same bands are tolerant of each other. A linear dominance hierarchy exists between females. Males of one-male groups can stay in their groups for six to eight years. Replacements in the resident males appear to occur without serious aggression. Upon reaching adulthood, males join all-male groups. Females sometimes leave their natal groups to avoid infanticide or inbreeding, reduce competition for food, or elevation of their social status. Females become sexually mature at the age of five years, they experience sexual swelling, which involves the genitals becoming reddened.
At one site, matings take place between February and November, while births occur between March and May. Copulations tend to last for half a minute; the male will mount her from behind. Both sexes will encourage mating; when soliciting, both sexes will make pouted faces. In addition, males will sometimes vocalize and females will present their backsides and shake their head from side to side. Mating pairs are sometimes harassed by subadults. Proboscis monkeys may engage in mounting with no reproductive purpose, such as playful and same-sex mounting, females will attempt to initiate copulation after they have conceived. Gestation last 166–200 days or more. Females tend to give birth in the early morning; the mothers eat the placenta and lick their infants clean. The young are weaned at seven months old; the nose of a young male grows until reaching adulthood. The mother will allow other members of her group to hold her infant; when a resident male in a one-male group is replaced, the infants are at risk of infanticide.
Proboscis monkeys are known to make various vocalizations. When communicating the status of group, males will emit honks, they have a special honk emitted towards infants, used for reassurance. Males will produce alarm calls to signal danger. Both sexes give threat calls. In addition and immature individuals will emit so-called "female calls" when angry. Honks and snarls are made during low-intensity agonistic encounters. Nonvocal displays include leaping-branch shaking, bare-teeth open mouth threats and erection in males, made in the same situations; the proboscis monkey is endemic to the island of Borneo and can be found on all three nations that divide the island: Brunei and Malaysia. It is most common in coastal areas and along rivers; this species is restricted to lowland habitats. It favors dipterocarp and riverine forests, it can be found in swamp forests, stunted swamp forests, rubber forests, rubber plantations, limestone hill forests, nypa swamps, nibong swamps, tall swamp forests, tr
Humans are the only extant members of the subtribe Hominina. Together with chimpanzees and orangutans, they are part of the family Hominidae. A terrestrial animal, humans are characterized by their erect bipedal locomotion. Early hominins—particularly the australopithecines, whose brains and anatomy are in many ways more similar to ancestral non-human apes—are less referred to as "human" than hominins of the genus Homo. Several of these hominins used fire, occupied much of Eurasia, gave rise to anatomically modern Homo sapiens in Africa about 315,000 years ago. Humans began to exhibit evidence of behavioral modernity around 50,000 years ago, in several waves of migration, they ventured out of Africa and populated most of the world; the spread of the large and increasing population of humans has profoundly affected much of the biosphere and millions of species worldwide. Advantages that explain this evolutionary success include a larger brain with a well-developed neocortex, prefrontal cortex and temporal lobes, which enable advanced abstract reasoning, problem solving and culture through social learning.
Humans use tools better than any other animal. Humans uniquely use such systems of symbolic communication as language and art to express themselves and exchange ideas, organize themselves into purposeful groups. Humans create complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established an wide variety of values, social norms, rituals, which together undergird human society. Curiosity and the human desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, mythology, religion and numerous other fields of knowledge. Though most of human existence has been sustained by hunting and gathering in band societies many human societies transitioned to sedentary agriculture some 10,000 years ago, domesticating plants and animals, thus enabling the growth of civilization; these human societies subsequently expanded, establishing various forms of government and culture around the world, unifying people within regions to form states and empires.
The rapid advancement of scientific and medical understanding in the 19th and 20th centuries permitted the development of fuel-driven technologies and increased lifespans, causing the human population to rise exponentially. The global human population was estimated to be near 7.7 billion in 2015. In common usage, the word "human" refers to the only extant species of the genus Homo—anatomically and behaviorally modern Homo sapiens. In scientific terms, the meanings of "hominid" and "hominin" have changed during the recent decades with advances in the discovery and study of the fossil ancestors of modern humans; the clear boundary between humans and apes has blurred, resulting in now acknowledging the hominids as encompassing multiple species, Homo and close relatives since the split from chimpanzees as the only hominins. There is a distinction between anatomically modern humans and Archaic Homo sapiens, the earliest fossil members of the species; the English adjective human is a Middle English loanword from Old French humain from Latin hūmānus, the adjective form of homō "man."
The word's use as a noun dates to the 16th century. The native English term man can refer to the species as well as to human males, or individuals of either sex; the species binomial "Homo sapiens" was coined by Carl Linnaeus in his 18th-century work Systema Naturae. The generic name "Homo" is a learned 18th-century derivation from Latin homō "man," "earthly being"; the species-name "sapiens" means "wise" or "sapient". Note that the Latin word homo refers to humans of either gender, that "sapiens" is the singular form; the genus Homo evolved and diverged from other hominins in Africa, after the human clade split from the chimpanzee lineage of the hominids branch of the primates. Modern humans, defined as the species Homo sapiens or to the single extant subspecies Homo sapiens sapiens, proceeded to colonize all the continents and larger islands, arriving in Eurasia 125,000–60,000 years ago, Australia around 40,000 years ago, the Americas around 15,000 years ago, remote islands such as Hawaii, Easter Island and New Zealand between the years 300 and 1280.
The closest living relatives of humans are gorillas. With the sequencing of the human and chimpanzee genomes, current estimates of similarity between human and chimpanzee DNA sequences range between 95% and 99%. By using the technique called a molecular clock which estimates the time required for the number of divergent mutations to accumulate between two lineages, the approximate date for the split between lineages can be calculated; the gibbons and orangutans were the first groups to split from the line leading to the h
Micropterigoidea is the superfamily of "mandibulate archaic moths", all placed in the single family Micropterigidae, containing about 20 living genera. They are considered the most primitive extant lineage of Lepidoptera. Micropterix Hübner, 1825 Epimartyria Walsingham, 1898 Issikiomartyria Hashimoto, 2006 Kurokopteryx Hashimoto, 2006 Micropardalis Meyrick, 1912 Neomicropteryx Issiki, 1931 Palaeomicra Meyrick, 1888 Palaeomicroides Issiki, 1931 Paramartyria Issiki, 1931 Vietomartyria Mey, 1997 Sabatinca Walker, 1863 Agrionympha Meyrick, 1921 Hypomartyria Kristensen & Nielsen 1982 Squamicornia Kristensen & Nielsen, 1982 Austromartyria Gibbs, 2010 Tasmantrix Gibbs, 2010 Zealandopterix Gibbs, 2010 Aureopterix Gibbs, 2010 Nannopterix Gibbs, 2010 †Auliepterix Kozlov, 1989 †Palaeolepidopterix Kozlov, 1989 †Palaeosabatinca Kozlov, 1989 †Parasabatinca Whalley, 1978 †Baltimartyria Skalski, 1995 †Moleropterix Engel & Kinzelbach, 2008 Kristensen, N. P. and E. S. Nielsen. 1979. A new subfamily of micropterigid moths from South America.
A contribution to the morphology and phylogeny of the Micropterigidae, with a generic catalogue of the family. Steenstrupia 5:69-147. Kristensen, N. P.. The non-Glossatan Moths. Ch. 4, pp. 41–49 in Kristensen, N. P.. Lepidoptera and Butterflies. Volume 1: Evolution and Biogeography. Handbuch der Zoologie. Eine Naturgeschichte der Stämme des Tierreiches / Handbook of Zoology. A Natural History of the phyla of the Animal Kingdom. Band / Volume IV Arthropoda: Insecta Teilband / Part 35: 491 pp. Walter de Gruyter, New York. O'Toole, Christopher. 2002. Firefly Encyclopedia of Insects and Spiders. ISBN 1-55297-612-2. Tree of Life Microleps U. S. A. Nearctic Watson, L. and Dallwitz, M. J. 2003 onwards. British insects: the families of Lepidoptera. Version: 29 December 2011 Detailed description and figures including wing venation
Elephant seals are large, oceangoing earless seals in the genus Mirounga. The two species, the northern elephant seal and the southern elephant seal, were both hunted to the brink of extinction by the end of the 19th century, but the numbers have since recovered; the northern elephant seal, somewhat smaller than its southern relative, ranges over the Pacific coast of the U. S. Canada and Mexico; the most northerly breeding location on the Pacific Coast is at Race Rocks, at the southern tip of Vancouver Island in the Strait of Juan de Fuca. The southern elephant seal is found in the Southern Hemisphere on islands such as South Georgia and Macquarie Island, on the coasts of New Zealand, South Africa, Argentina in the Peninsula Valdés. In southern Chile, there is a small colony of 120 animals at Jackson Bay, Admiralty Sound, Tierra del Fuego; the oldest known unambiguous elephant seal fossils are fragmentary fossils of an unnamed member of the tribe Miroungini described from the late Pliocene Petane Formation of New Zealand.
Teeth identified as representing an unnamed species of Mirounga have been found in South Africa, dated to the Miocene epoch. Elephant seals breed annually and are faithful to colonies that have established breeding areas. Elephant seals are marine mammals classified under the order Pinnipedia, which in Latin, means feather or fin footed. Elephant seals are considered true seals, fall under the family Phocidae. Phocids are characterized by having reduced limbs; the reduction of their limbs helps them be more streamlined and move in the water. However, it makes navigating on land a bit difficult because they cannot turn their hind flippers forward to walk like the Otariids. In addition, the hind flipper of elephant seals have a lot of surface area, which helps propel them in the water. Elephant seals spend the majority of their time underwater in search of food, can cover 60 miles a day when they head out to sea; when elephant seals are born, they can reach lengths up to 4 feet. Sexual dimorphism is prominently seen in elephant seals due to the fact that male elephant seals can weigh up to 10 times more than females.
The large proboscis, considered a secondary sexual characteristic, helps males assert dominance during mating season. Elephant seals take their name from the large proboscis of the adult male, which resembles an elephant's trunk; the bull's proboscis is used in producing extraordinarily loud roaring noises during the mating season. More however, the nose acts as a sort of rebreather, filled with cavities designed to reabsorb moisture from their exhalations; this is important during the mating season when the seals do not leave the beach to feed, must conserve body moisture as there is no incoming source of water. They are colossally large in comparison with other pinnipeds, with southern elephant seal bulls reaching a length of 5 m and a weight of 3,000 kg, are much larger than the adult females, with some exceptionally large males reaching up to 6 m in length and weighing 4,000 kg. Northern elephant seal bulls reach the heaviest weigh about 2,500 kg; the northern and southern elephant seal can be distinguished by looking at various external features.
On average, the southern elephant seal tends to be larger than the northern species. Adult male elephant seals belonging to the northern species tend to have a larger proboscis, thick chest area with a red coloration compared to the southern species. Females do not have the large proboscis and can be distinguished between species by looking at their nose characteristics. Southern females tend to have a smaller, blunt nose compared to northern females. Elephant seals spend up to 80% of their lives in the ocean, they can hold their breath for more than 100 minutes – longer than any other noncetacean mammal. Elephant seals dive to 1,550 m beneath the ocean's surface; the average depth of their dives is about 300 to 600 m for around 20 minutes for females and 60 minutes for males, as they search for their favorite foods, which are skates, squid, eels, small sharks and large fish. Their stomachs often contain gastroliths, they spend only brief amounts of time at the surface to rest in between dives.
Females tend to dive a bit deeper due to their prey source. Elephant seals are shielded from extreme cold more so than by fur, their hair and outer layers of skin molt in large patches. The skin has to be regrown by blood vessels reaching through the blubber; when molting occurs, the seal is susceptible to the cold, must rest on land, in a safe place called a "haul out". Northern males and young adults haul out during June to July to molt. Elephant seals have a large volume of blood, allowing them to hold a large amount of oxygen for use when diving, they have large sinuses in their abdomens to hold blood and can store oxygen in their muscles with increased myoglobin concentrations in muscle. In addition, they have a larger proportion of oxygen-carrying red blood cells; these adaptations allow elephant seals to dive to such depths and remain underwater for up to two hours. Elephant seals are able to slow down their heartbeat and divert blood f
In teratology, proboscis is a blind-ended, tubelike structure located in the middle of the face. Proboscis formation are classified in four general types: holoprosencephalic proboscis, lateral nasal proboscis, supernumerary proboscis, disruptive proboscis. Holoprosencephalic proboscis is found in holoprosencephaly. In cyclopia or ethmocephaly, proboscis is an abnormally formed nose. In cyclopia, a single eye in the middle of the face is associated with arrhinia and with proboscis formation above the eye. In ethmocephaly, two separate hypoteloric eyes are associated with arrhinia and proboscis formation above the eye. In cebocephaly, no proboscis formation occurs. Lateral nasal proboscis is a tubular proboscis-like structure and represents incomplete formation of one side of the nose; the olfactory bulb is rudimentary on the side involved in the malformation. The tear duct, nasal bone, nasal cavity, maxillary sinus, ethmoidal sinuses, another nasal structure known as the cribriform plate cells are missing on this side as well.
Ocular hypertelorism may be present. The proboscis lateralis is a rare nasal anomaly. Supernumerary proboscis is found when both nostrils are formed and there is a proboscis in addition to it. Accessory proboscis arise from a supernumerary olfactory placode. Disruptive proboscis occur if an hamartoneoplastic lesion arises in the prosencephalon of the embryo in its early stages of development. John M. Guerrero, Martin S. Cogen, David R. Kelly, Brian J. Wiatrak. Proboscis Lateralis. Arch Ophthalmol. 2001. I Kjaer, JW Keeling; the midline craniofacial skeleton in holoprosencephalic fetuses. Journal of medical genetics, 1991 S Acarturk, K Kivanc, E Atilla. Proboscis lateralis: evaluation of the anomaly and a review of two cases. Plastic and Reconstructive Surgery, June 2006 UH Vyas, SC Raibagkar, HJ Vora. Proboscis lateralis-A 17 years follow up, a case report. Indian J Plastic Surg January–June 2003 Vol 36 Issue 1
Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal refers only to non-human animals; the study of non-human animals is known as zoology. Most living animal species are in the Bilateria, a clade whose members have a bilaterally symmetric body plan; the Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes and molluscs—and the deuterostomes, containing the echinoderms and chordates.
Life forms interpreted. Many modern animal phyla became established in the fossil record as marine species during the Cambrian explosion which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified. Aristotle divided animals into those with those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between animal taxa. Humans make use of many other animal species for food, including meat and eggs. Dogs have been used in hunting, while many aquatic animals are hunted for sport.
Non-human animals have appeared in art from the earliest times and are featured in mythology and religion. The word "animal" comes from the Latin animalis, having soul or living being; the biological definition includes all members of the kingdom Animalia. In colloquial usage, as a consequence of anthropocentrism, the term animal is sometimes used nonscientifically to refer only to non-human animals. Animals have several characteristics. Animals are eukaryotic and multicellular, unlike bacteria, which are prokaryotic, unlike protists, which are eukaryotic but unicellular. Unlike plants and algae, which produce their own nutrients animals are heterotrophic, feeding on organic material and digesting it internally. With few exceptions, animals breathe oxygen and respire aerobically. All animals are motile during at least part of their life cycle, but some animals, such as sponges, corals and barnacles become sessile; the blastula is a stage in embryonic development, unique to most animals, allowing cells to be differentiated into specialised tissues and organs.
All animals are composed of cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. During development, the animal extracellular matrix forms a flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible; this may be calcified, forming structures such as shells and spicules. In contrast, the cells of other multicellular organisms are held in place by cell walls, so develop by progressive growth. Animal cells uniquely possess the cell junctions called tight junctions, gap junctions, desmosomes. With few exceptions—in particular, the sponges and placozoans—animal bodies are differentiated into tissues; these include muscles, which enable locomotion, nerve tissues, which transmit signals and coordinate the body. There is an internal digestive chamber with either one opening or two openings. Nearly all animals make use of some form of sexual reproduction, they produce haploid gametes by meiosis.
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement, it first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm develops between them; these germ layers differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. In some species, such as the splendid fairywren, females benefit by mating with multiple males, thus producing more offspring of higher genetic quality; some animals are capable of asexual reproduction, which results