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47-572: The Mount Namsan belt is anchored by Mount Namsan, a mountain that was held sacred by the Silla people. Both Buddhist artifacts and artifacts related to Shamanism that predate the introduction of Buddhism to Korea have been found at this site. Buddhist artifacts include the ruins of 122 temples, 53 stone statues, 64 stone pagodas, and sixteen stone lanterns. Other notable sites include the Namsan Mountain Fortress (built in 591 CE),

94-429: A gram (around 0.02 oz). Some eggs laid by reptiles and most fish, amphibians, insects, and other invertebrates can be even smaller. Reproductive structures similar to the egg in other kingdoms are termed " spores ", or in spermatophytes " seeds ", or in gametophytes "egg cells". Several major groups of animals typically have readily distinguishable eggs. The most common reproductive strategy for fish

141-542: A green or blue ground colour, while protoporphyrin IX produces reds and browns as a ground colour or as spotting. Non-passerines typically have white eggs, except in some ground-nesting groups such as the Charadriiformes , sandgrouse and nightjars , where camouflage is necessary, and some parasitic cuckoos which have to match the passerine host's egg. Most passerines, in contrast, lay coloured eggs, even if there

188-436: A longer fetal development. Comparatively anatomically simple animals will be able to go through the full development and leave the egg in a form reminiscent of the adult animal. This is the situation found in hagfish and some snails . Animals with smaller size eggs or more advanced anatomy will still have a distinct larval stage, though the larva will be basically similar to the adult animal, as in lampreys , coelacanth and

235-519: A mural painting on birch bark saddle flap of a winged horse. This cluster of historic remains is centered around the ruins of Hwangnyongsa Temple and Bunhwangsa Temple. According to the excavated foundation stones, Hwangnyongsa was the largest temple ever built in Korea and covered 72,500 m. The Bunhwagsa Temple exists today at a fraction of its size. In the past, it was one of the most important Buddhist temples. A stone pagoda made from brick-like stones

282-403: A naked egg cell. Mesolecithal eggs have comparatively more yolk than the microlecithal eggs. The yolk is concentrated in one part of the egg (the vegetal pole ), with the cell nucleus and most of the cytoplasm in the other (the animal pole ). The cell cleavage is uneven, and mainly concentrated in the cytoplasma-rich animal pole. The larger yolk content of the mesolecithal eggs allows for

329-528: A roof was erected to protect the statues. The sitting stone statue of Buddha in the Mireuk valley, the sitting image of Bodhisattva carved into a stone wall at Sinseonam are two of the designated national treasures. In addition, there are sites of local significance, such as the sitting figure of Sakyamuni carved on a rock in Samneung Valley. This figure is about 7 metres high and about 5 metres wide. It

376-523: A shell and would dry out in the air. Even air-breathing amphibians lay their eggs in water, or in protective foam as with the Coast foam-nest treefrog, Chiromantis xerampelina . Bird eggs are laid by females and incubated for a time that varies according to the species; a single young hatches from each egg. Average clutch sizes range from one (as in condors ) to about 17 (the grey partridge ). Some birds lay eggs even when not fertilized (e.g. hens ); it

423-460: A warm and favorable temperature range while the embryo grows. When the embryo is adequately developed it hatches, i.e., breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark and was 30 cm × 14 cm × 9 cm (11.8 in × 5.5 in × 3.5 in) in size. Whale shark eggs typically hatch within

470-522: A white horse kneeling by Najeong well. When approaching the site to take a closer look, the horse disappeared, but he found an egg . From the egg hatched a boy who was chosen to become king at the age of 13. The Yangsanjae shrine was built in honour of a founder who lived in Seorabeol before the Silla kingdom was established. A famous site is the three stone Buddha statue of Bae-ri. The site features three Buddha figures carved into stone. More recently,

517-549: Is a popular ruin. It is believed to have had seven or nine stories but only three remain today. This portion of the property includes the ruins of the Myeonghwal mountain fortress (Myeonghwal Sanseong) situated on Mount Myeonghwal at Bomun Lake about 6 kilometres east of the downtown of Gyeongju. Namsan (Gyeongju) Namsan ( Korean : 남산 , "South Mountain") is a 494-meter peak in the heart of Gyeongju National Park , just south of Gyeongju , South Korea . The mountain

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564-414: Is known as oviparity , in which the female lays undeveloped eggs that are externally fertilized by a male. Typically large numbers of eggs are laid at one time (an adult female cod can produce 4–6 million eggs in one spawning) and the eggs are then left to develop without parental care. When the larvae hatch from the egg, they often carry the remains of the yolk in a yolk sac which continues to nourish

611-425: Is likely to have arisen due to evolution via natural selection. In contrast, many hole-nesting birds have nearly spherical eggs. Many animals feed on eggs. For example, principal predators of the black oystercatcher 's eggs include raccoons , skunks , mink , river and sea otters , gulls , crows and foxes . The stoat ( Mustela erminea ) and long-tailed weasel ( M. frenata ) steal ducks' eggs. Snakes of

658-416: Is no need of cryptic colors. However, some have suggested that the protoporphyrin markings on passerine eggs actually act to reduce brittleness by acting as a solid-state lubricant. If there is insufficient calcium available in the local soil, the egg shell may be thin, especially in a circle around the broad end. Protoporphyrin speckling compensates for this, and increases inversely to the amount of calcium in

705-446: Is not uncommon for pet owners to find their lone bird nesting on a clutch of unfertilized eggs, which are sometimes called wind-eggs. The default colour of vertebrate eggs is the white of the calcium carbonate from which the shells are made, but some birds, mainly passerines , produce coloured eggs. The colour comes from pigments deposited on top of the calcium carbonate base; biliverdin and its zinc chelate , and bilirubin , give

752-486: Is the biggest sitting statue at Namsam. Cheongwansa is a historic temple. Namsan is not only known for the Silla remains, but also appreciated by visitors for its natural environment. 35°46′05″N 129°13′32″E  /  35.76806°N 129.22556°E  / 35.76806; 129.22556 Egg (biology) An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote ) and to incubate from it an embryo within

799-408: Is thought to act as a shock absorber, protecting the calcite shell from fracture during incubation, such as colliding with other eggs in the nest. Most bird eggs have an oval shape , with one end rounded and the other more pointed. This shape results from the egg being forced through the oviduct . Muscles contract the oviduct behind the egg, pushing it forward. The egg's wall is still shapeable, and

846-399: Is usually motile whereas the female gamete cell, the ovum , is generally larger and sessile . The male and female gametes combine to produce the zygote cell. In multicellular organisms, the zygote subsequently divides in an organised manner into smaller more specialised cells, so that this new individual develops into an embryo . In most animals, the embryo is the sessile initial stage of

893-405: Is within easy reach from the city and attracts a large number of domestic tourists. Namsan covers an area of about 8 km (north-south) by 12 km (east-west). Some 180 peaks are counted, of which Geumobong (468 m) and Gouibong (495 m) are the best-known. There are about 40 valleys. Namsan is home to many historic and cultural remains, and is now part of the historic area around Gyeongju that

940-750: The Poseokjeong Pavilion site (famous for its abalone-shaped watercourse), and the Seochulji Pond. Mount Namsan is famous for the various Buddhist images carved into the rocks and also show the progression and maturation of Silla sculpture during the Unified Silla period. The most famous example of these reliefs is the Buddha Rock. This bas-relief is located in the Tapgol Valley and consists of three walls decorated with

987-415: The coelacanths can reach a size of 9 cm (3.5 in) in diameter, and the young go through full development while in the uterus , living on the copious yolk. Animals are commonly classified by their manner of reproduction, at the most general level distinguishing egg-laying (Latin. oviparous ) from live-bearing (Latin. viviparous ). These classifications are divided into more detail according to

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1034-594: The planula , and either develops directly into the adult animals or forms new adult individuals through a process of budding . Microlecithal eggs require minimal yolk mass. Such eggs are found in flatworms , roundworms , annelids , bivalves , echinoderms , the lancelet and in most marine arthropods . In anatomically simple animals, such as cnidarians and flatworms, the fetal development can be quite short, and even microlecithal eggs can undergo direct development. These small eggs can be produced in large numbers. In animals with high egg mortality, microlecithal eggs are

1081-411: The salamanders . Eggs with a large yolk are called macrolecithal. The eggs are usually few in number, and the embryos have enough food to go through full fetal development in most groups. Macrolecithal eggs are only found in selected representatives of two groups: Cephalopods and vertebrates . Macrolecithal eggs go through a different type of development than other eggs. Due to the large size of

1128-479: The 7th and 10th century. 12 of these relicts are designated national treasures. The concentration of remains is particularly high at the foothills west of Namsan. The remains are thought to reflect the rise and fall of the Silla kingdom. Najeong Well is the mystic birthplace of King Park Hyeokgeose , founder of the Silla dynasty. Only a small stone with inscriptions remains of this site. According to legend, one day in 69 BC Seobeol—chieftain of Goheo village—spotted

1175-413: The adult body, and by the yolk which the egg provides to nourish the embryo. Vertebrate eggs can be classified by the relative amount of yolk . Simple eggs with little yolk are called microlecithal , medium-sized eggs with some yolk are called mesolecithal , and large eggs with a large concentrated yolk are called macrolecithal . This classification of eggs is based on the eggs of chordates , though

1222-540: The air. Often the sex of the developing embryo is determined by the temperature of the surroundings, with cooler temperatures favouring males. Not all reptiles lay eggs; some are viviparous ("live birth"). Dinosaurs laid eggs, some of which have been preserved as petrified fossils. Among mammals, early extinct species laid eggs, as do platypuses and echidnas (spiny anteaters). Platypuses and two genera of echidna are Australian monotremes . Marsupial and placental mammals do not lay eggs, but their unborn young do have

1269-407: The basic principle extends to the whole animal kingdom . Small eggs with little yolk are called microlecithal. The yolk is evenly distributed, so the cleavage of the egg cell cuts through and divides the egg into cells of fairly similar sizes. In sponges and cnidarians , the dividing eggs develop directly into a simple larva, rather like a morula with cilia . In cnidarians, this stage is called

1316-492: The biological sense. In placental mammals , the egg itself is void of yolk, but develops an umbilical cord from structures that in reptiles would form the yolk sac. Receiving nutrients from the mother, the fetus completes the development while inside the uterus. Eggs are common among invertebrates , including insects , spiders , mollusks , and crustaceans . All sexually reproducing life, including both plants and animals, produces gametes . The male gamete cell, sperm ,

1363-404: The cells of incipient multicellular organisms. The cycle of the egg's formation is started by the gamete ovum being released ( ovulated ) and egg formation being started. The finished egg is then ovipositioned and eventual egg incubation can start. Scientists often classify animal reproduction according to the degree of development that occurs before the new individuals are expelled from

1410-401: The complex tissues that identify amniotes. The eggs of the egg-laying mammals (the platypus and the echidnas ) are macrolecithal eggs very much like those of reptiles . The eggs of marsupials are likewise macrolecithal, but rather small, and develop inside the body of the female, but do not form a placenta . The young are born at a very early stage, and can be classified as a " larva " in

1457-476: The crowded cliff ledges on which they breed. Yolks of birds' eggs are yellow from carotenoids , it is affected by their living conditions and diet. Bird eggshells are diverse. For example: Tiny pores in bird eggshells allow the embryo to breathe. The domestic hen 's egg has around 7000 pores. Some bird eggshells have a coating of vaterite spherules , which is a rare polymorph of calcium carbonate. In Greater Ani Crotophaga major this vaterite coating

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1504-460: The egg until the embryo has become an animal fetus that can survive on its own, at which point the animal hatches. Most arthropods , vertebrates (excluding live-bearing mammals ), and mollusks lay eggs, although some, such as scorpions , do not. Reptile eggs, bird eggs , and monotreme eggs are laid out of water and are surrounded by a protective shell , either flexible or inflexible. Eggs laid on land or in nests are usually kept within

1551-477: The famous Cheomseongdae Observatory. This belt consists of three groups of royal tombs. Most of the tumuli are shaped like domes or mounds of earth. However, some are shaped like gourds or half-moons. Excavated tombs reveal wooden coffins covered with gravel and rich grave goods of gold, glass, and quality ceramics. A famous example of a tomb in this park is the Heavenly Horse Tomb which contained

1598-650: The genera Dasypeltis and Elachistodon specialize in eating eggs. Brood parasitism occurs in birds when one species lays its eggs in the nest of another. In some cases, the host's eggs are removed or eaten by the female, or expelled by her chick. Brood parasites include the cowbirds and many Old World cuckoos . Like amphibians, amniotes are air-breathing vertebrates , but they have complex eggs or embryos , including an amniotic membrane . Amniotes include reptiles (including dinosaurs and their descendants, birds) and mammals. Reptile eggs are often rubbery and are always initially white. They are able to survive in

1645-612: The images of Buddha and his disciples. Tumuli of the Silla kings dating from the 2nd century until the 10th century are also found at this belt. The main attractions of this portion of the Gyeongju Historic Areas are the ruins of Banwolseong (Half-moon Palace/Fortress), the Gyerim forest, the ruins and reconstructions of the pavilions at the artificial Anapji Pond, the ruins of the Imhaejeon Palace, and

1692-494: The individual life cycle, and is followed by the emergence (that is, the hatching) of a motile stage. The zygote or the ovum itself or the sessile organic vessel containing the developing embryo may be called the egg. A recent proposal suggests that the phylotypic animal body plans originated in cell aggregates before the existence of an egg stage of development . Eggs, in this view, were later evolutionary innovations , selected for their role in ensuring genetic uniformity among

1739-411: The larvae for a few days as they learn how to swim. Once the yolk is consumed, there is a critical point after which they must learn how to hunt and feed or they will die. A few fish, notably the rays and most sharks use ovoviviparity in which the eggs are fertilized and develop internally. However, the larvae still grow inside the egg consuming the egg's yolk and without any direct nourishment from

1786-418: The mother also providing direct nourishment. The eggs of fish and amphibians are jellylike. Cartilaginous fish (sharks, skates, rays, chimaeras) eggs are fertilized internally and exhibit a wide variety of both internal and external embryonic development. Most fish species spawn eggs that are fertilized externally, typically with the male inseminating the eggs after the female lays them. These eggs do not have

1833-409: The mother. At 1.5 kg (3.3 lb) and up to 17.8 cm × 14 cm (7.0 in × 5.5 in), the ostrich egg is the largest egg of any living bird, though the extinct elephant bird and some non-avian dinosaurs laid larger eggs. The bee hummingbird produces the smallest known bird egg, which measures between 6.35–11.4 millimetres (0.250–0.449 in) long and weighs half of

1880-432: The mother. The mother then gives birth to relatively mature young. In certain instances, the physically most developed offspring will devour its smaller siblings for further nutrition while still within the mother's body. This is known as intrauterine cannibalism . In certain scenarios, some fish such as the hammerhead shark and reef shark are viviparous , with the egg being fertilized and developed internally, but with

1927-421: The norm, as in bivalves and marine arthropods. However, the latter are more complex anatomically than e.g. flatworms, and the small microlecithal eggs do not allow full development. Instead, the eggs hatch into larvae , which may be markedly different from the adult animal. In placental mammals, where the embryo is nourished by the mother throughout the whole fetal period, the egg is reduced in size to essentially

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1974-413: The pointed end develops at the back. . One hypothesis is that long, pointy eggs are an incidental consequence of having a streamlined body typical of birds with strong flying abilities; flight narrows the oviduct, which changes the type of egg a bird can lay. Cliff-nesting birds often have highly conical eggs. They are less likely to roll off, tending instead to roll around in a tight circle; this trait

2021-568: The small size of the eggs does not allow for direct development, and the eggs hatch to a larval stage ("fry"). In terrestrial animals with macrolecithal eggs, the large volume to surface ratio necessitates structures to aid in transport of oxygen and carbon dioxide, and for storage of waste products so that the embryo does not suffocate or get poisoned from its own waste while inside the egg, see amniote . In addition to bony fish and cephalopods, macrolecithal eggs are found in cartilaginous fish , reptiles , birds and monotreme mammals. The eggs of

2068-416: The soil. For the same reason, later eggs in a clutch are more spotted than early ones as the female's store of calcium is depleted. The color of individual eggs is also genetically influenced, and appears to be inherited through the mother only, suggesting that the gene responsible for pigmentation is on the sex-determining W chromosome (female birds are WZ, males ZZ). It used to be thought that color

2115-432: The yolk, the cell division can not split up the yolk mass. The fetus instead develops as a plate-like structure on top of the yolk mass, and only envelopes it at a later stage. A portion of the yolk mass is still present as an external or semi-external yolk sac at hatching in many groups. This form of fetal development is common in bony fish , even though their eggs can be quite small. Despite their macrolecithal structure,

2162-581: Was added to the UNESCO list of World Heritage in 2000. Namsan is home to many remains from the Silla period, including some tombs of Silla rulers. There are hundreds of remains scattered around the mountain. Poseokjeong is one of the most famous of these sites, lying at the foot of Namsan. Other remains include Korean Buddhist art, sculptures, about 80 carved reliefs, about 60 stone pagodas and remains of about 100 temples and palaces mostly built between

2209-456: Was applied to the shell immediately before laying, but subsequent research shows that coloration is an integral part of the development of the shell, with the same protein responsible for depositing calcium carbonate, or protoporphyrins when there is a lack of that mineral. In species such as the common guillemot , which nest in large groups, each female's eggs have very different markings, making it easier for females to identify their own eggs on

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