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Santiago Island (Galápagos)
Santiago Island () is one of the Galápagos Islands. It is also known as San Salvador, named after the first island discovered by Columbus in the Caribbean Sea (see San Salvador Island), or as James Island. The island, which consists of two overlapping volcanoes, has an area of and a maximum altitude of , atop the northwestern shield volcano. The volcano in the island's southeast erupted along a linear fissure, and is much lower. The oldest lava flows on the island date back to 750,000 years ago. Geology Santiago Island was formed from a shield volcano eponymously named Santiago. The low, flat summits of the volcano allowed the low-viscosity lava to flow for large distances from the source vents. The volcanic origin of the island has led it to be dotted with holocene pyroclastic rock that can be found across the island. On the eastern and western sides of the island, tuff cones, formed from the rapid interaction of hot lava and water, are visible. The summit of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galápagos Islands
The Galápagos Islands (Spanish: , , ) are an archipelago of volcanic islands. They are distributed on each side of the equator in the Pacific Ocean, surrounding the centre of the Western Hemisphere, and are part of the Republic of Ecuador. Located west of continental Ecuador, the islands are known for their large number of endemic species that were studied by Charles Darwin during the second voyage of HMS ''Beagle''. His observations and collections contributed to the inception of Darwin's theory of evolution by means of natural selection. The Galápagos Islands and their surrounding waters form the Galápagos Province of Ecuador, the Galápagos National Park, and the Galápagos Marine Reserve. The principal language on the islands is Spanish. The islands have a population of slightly over 25,000. The first recorded visit to the islands happened by chance in 1535, when Fray Tomás de Berlanga, the Bishop of Panamá, was surprised to find this undiscovered land on a vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Rock
Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroclasts. Pyroclastic rocks are a type of volcaniclastic deposit, which are deposits made predominantly of volcanic particles. 'Phreatic' pyroclastic deposits are a variety of pyroclastic rock that forms from volcanic steam explosions and they are entirely made of accidental clasts. 'Phreatomagmatic' pyroclastic deposits are formed from explosive interaction of magma with groundwater. Unconsolidated accumulations of pyroclasts are described as tephra. Tephra may become lithified to a pyroclastic rock by cementation or chemical reactions as the result of the passage of hot gases (fumarolic alteration) or groundwater (e.g. hydrothermal alteration and diagenesis) and burial, or, if it is emplaced at temperatures so hot that the soft glassy pyrocl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended from a common ancestor is now generally accepted and considered a fundamental concept in science. In a joint publication with Alfred Russel Wallace, he introduced his scientific theory that this branching pattern of evolution resulted from a process he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding. Darwin has been described as one of the most influential figures in human history and was honoured by burial in Westminster Abbey. Darwin's early interest in nature led him to neglect his medical education at the University of Edinburgh; instead, he helped to investigate marine invertebrates. His studies at the University of Cambridge's Christ's Col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microlophus
''Microlophus'' is a genus of tropidurid lizards native to South America. Around 20 species are recognized and 10 of these are endemic to the Galápagos Islands, where they are commonly known as lava lizardsBenavides E, Baum R, Snell HM, Snell HL, Sites JW Jr (2009)"Island Biogeography of Galápagos Lava Lizards (Tropiduridae: ''Microlophus''): Species Diversity and Colonization of the Archipelago". (.pdf) ''Evolution'' 63 (6): 1606–1626. (they are sometimes placed in ''Tropidurus'' instead). The remaining, which often are called Pacific iguanas, are found in the Andes and along the Pacific coasts of Chile, Peru, and Ecuador. The distribution of the lava lizards and their variations in shape, colour, and behaviour show the phenomenon of adaptive radiation so typical of the inhabitants of this archipelago. One species occurs on all the central and western islands, which were perhaps connected during periods of lower sea levels, while one species each occurs on six other more pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rice Rat
Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of the family Cricetidae. It includes about 120 species in about thirty genera,Weksler et al., 2006, table 1 distributed from the eastern United States to the southernmost parts of South America, including many offshore islands. It is part of the clade Oryzomyalia, which includes most of the South American Sigmodontinae. The name ''Oryzomyini'' derives from that of its type genus, '' Oryzomys'', which means "rice rat" or "rice mouse". Many species are also known as rice rats. Taxonomy Contents of Oryzomyini An oryzomyine group was first envisaged by Oldfield Thomas in the early 20th century. He defined it to include pentalophodont species, which have a mesoloph(id) on the upper and lower molars, with a long palate (extending past the third molars). Thomas included '' Oligoryzomys'', ''Oecomys'', and '' Oryzomys'' (which included many species now in other genera), as well as '' Rhagomys'', which is currently class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bottlenose Dolphin
Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the common bottlenose dolphin (''Tursiops truncatus'') and the Indo-Pacific bottlenose dolphin (''Tursiops aduncus''). Others, like the Burrunan dolphin (''Tursiops (aduncus) australis''), may be alternately considered their own species or be subspecies of ''T. aduncus''. Bottlenose dolphins inhabit warm and temperate seas worldwide, being found everywhere except for the Arctic and Antarctic Circle regions. Their name derives from the Latin ''tursio'' (dolphin) and ''truncatus'' for their characteristic truncated teeth. Numerous investigations of bottlenose dolphin intelligence have been conducted, examining mimicry, use of artificial language, object categorization, and self-recognition. They can use tools (sponging; using marine sponges to forage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galápagos Land Iguana
The Galápagos land iguana (''Conolophus subcristatus'') is a very large species of lizard in the family Iguanidae. It is one of three species of the genus ''Conolophus''. It is endemic to the Galápagos Islands, in the dry lowlands of the islands of Fernandina, Isabela, Santa Cruz, North Seymour, Baltra, and South Plaza. Taxonomy The land iguanas in the Galápagos vary in morphology and coloration among different populations. In addition to the relatively widespread and well-known Galápagos land iguana (''C. subcristatus''), there are two other species of ''Conolophus'': the Galápagos pink land iguana (''C. marthae'') from northern Isabela Island and the Santa Fe land iguana (''C. pallidus'') from Santa Fe Island. Based on mtDNA, land iguanas and marine iguanas diverged about 8–10 million years ago. Within the land iguana genus, the oldest split based on mtDNA, about 5.7 million years old, is between ''C. subcristatus'' and ''C. marthae''. A more recent study that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Iguana
The marine iguana (''Amblyrhynchus cristatus''), also known as the sea iguana, saltwater iguana, or Galápagos marine iguana, is a species of iguana found only on the Galápagos Islands (Ecuador). Unique among modern lizards, it is a marine reptile that has the ability to forage in the sea for algae, which makes up almost all of its diet. Marine iguanas are the only extant lizard that spends time in a marine environment. Large males are able to dive to find this food source, while females and smaller males feed during low tide in the intertidal zone. They mainly live in colonies on rocky shores where they bask after visiting the relatively cold water or intertidal zone, but can also be seen in marshes, mangrove swamps and beaches. Large males defend territories for a short period, but smaller males have other breeding strategies. After mating, the female digs a nest hole in the soil where she lays her eggs, leaving them to hatch on their own a few months later. Marine iguanas vary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grapsus Grapsus
''Grapsus grapsus'' is one of the most common crabs along the western coast of the Americas. It is known as the red rock crab, or, along with crabs such as ''Percnon gibbesi'', as the Sally Lightfoot crab. Distribution ''Grapsus grapsus'' is found along the Pacific coast of Mexico, Central America, and South America (as far south as northern Peru), and on nearby islands, including the Galápagos Islands. It is also found along the Atlantic coast of South America, but is replaced in the eastern Atlantic Ocean ( Ascension Island and West Africa) by its congener ''Grapsus adscensionis''. Description ''Grapsus grapsus'' is a typically shaped crab, with five pairs of legs, the front two bearing small, blocky, symmetrical chelae (claws). The other legs are broad and flat, with only the tips touching the substrate. The crab's round, flat carapace is slightly longer than . Young ''G. grapsus'' are black or dark brown in colour and are camouflaged well on the black lava coasts of vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galápagos Sea Lion
The Galápagos sea lion (''Zalophus wollebaeki'') is a species of sea lion that lives and breeds on the Galápagos Islands and, in smaller numbers, on Isla de la Plata (Ecuador). Being fairly social, they are often spotted sun-bathing on sandy shores or rock groups, or gliding through the surf. They are the smallest sea lion species. Taxonomy This species was first described by E. Sivertsen in 1953. It has been considered a subspecies of ''Zalophus californianus'' (called ''Z. c. wollebaeki'') by many authors. But recent genetic data supports ''Z. wollebaeki'' as a separate species. The species belongs to the family Otariidae and genus '' Zalophus''. Physical characteristics Slightly smaller than their Californian relatives, Galápagos sea lions range from in length and weigh between , with the males averaging larger than females. Adult males also tend to have a thicker, more robust neck, chest, and shoulders in comparison to their slender abdomen. Females, by contra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galápagos Fur Seal
The Galápagos fur seal (''Arctocephalus galapagoensis'') is one of eight seals in the genus ''Arctocephalus'' and one of nine seals in the subfamily '' Arctocephalinae.'' It is the smallest of all of the eared seals. They are endemic to the Galápagos Islands in the eastern Pacific. The total estimated population as of 1970 was said to be about 30,000, although the population has been said to be on the decline since the 1980s due to environmental factors such as pollution, disease, invasive species, and their limited territory. Due to the population having been historically vulnerable to hunting, the Galápagos fur seal has been protected by the Ecuadorian government since 1934 Description Galápagos fur seals are the smallest otariids. They are born with a black natal coat that they molt to reveal a lighter brown coat before becoming adults. Of the otariids, Galápagos fur seals display the least amount of sexual dimorphism. The males are up to 2x heavier than the females an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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