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83-516: Testudo (which meant " tortoise " in classical Latin) may refer to: Battering ram , an armored siege engine with metal plating on the top to protect from missiles fired from above Chevrolet Testudo , a concept car designed and built by Bertone on a Chevrolet Corvair unibody chassis Steel Testudo or the Nationalist-Socialist Party of Romania, 1930s political party Testudo (mascot) ,

166-468: A 13th subspecies ( C. n. abingdonii ) had only a single known living individual, kept in captivity and nicknamed Lonesome George until his death in June 2012. Two other subspecies, C. n. niger (the type subspecies of Galápagos tortoise) from Floreana Island and an undescribed subspecies from Santa Fe Island are known to have gone extinct in the mid-late 19th century. Conservation efforts, beginning in

249-614: A South American ancestor, while the Indian Ocean tortoises derived from ancestral populations on Madagascar. At the end of the 19th century, Georg Baur and Walter Rothschild recognised five more populations of Galápagos tortoise. In 1905–06, an expedition by the California Academy of Sciences , with Joseph R. Slevin in charge of reptiles, collected specimens which were studied by Academy herpetologist John Van Denburgh . He identified four additional populations, and proposed

332-625: A female spur-thighed tortoise , lived to be about 165 years old. For 38 years, she was carried as a mascot aboard various ships in Britain's Royal Navy . Then in 1892, at age 53, she retired to the grounds of Powderham Castle in Devon . Up to the time of her death in 2004, she was believed to be the United Kingdom's oldest resident. Jonathan , a Seychelles giant tortoise living on the island of St Helena , may be as old as 192 years. DNA analysis of

415-631: A greater chance of surviving the journey over water from the mainland as they can hold their heads a greater height above the water level and have a smaller surface area/volume ratio , which reduces osmotic water loss. Their significant water and fat reserves would allow the tortoises to survive long ocean crossings without food or fresh water, and to endure the drought-prone climate of the islands. A larger size allowed them to better tolerate extremes of temperature due to gigantothermy . Fossil giant tortoises from mainland South America have been described that support this hypothesis of gigantism that pre-existed

498-618: A large unprotected gap remains over the neck, evidence of the lack of predation during the evolution of this structure. Larger islands with humid highlands over 800 m (2,600 ft) in elevation, such as Santa Cruz, have abundant vegetation near the ground. Tortoises native to these environments tend to have domed shells and are larger, with shorter necks and limbs. Saddleback tortoises originate from small islands less than 500 m (1,600 ft) in elevation with dry habitats (e.g. Española and Pinzón) that are more limited in food and other resources. Two lineages of Galápagos tortoises possess

581-410: A longer, more protruding neck plate than their female counterparts, while in others, the claws are longer on the females. The male plastron is curved inwards to aid reproduction. The easiest way to determine the sex of a tortoise is to look at the tail. The females, as a general rule, have smaller tails, dropped down, whereas the males have much longer tails which are usually pulled up and to the side of

664-453: A more specific term for slow-moving terrestrial species. General American usage agrees; turtle is often a general term; tortoise is used only in reference to terrestrial turtles or, more narrowly, only those members of Testudinidae, the family of modern land tortoises; and terrapin may refer to turtles that are small and live in fresh and brackish water, in particular the diamondback terrapin ( Malaclemys terrapin ). In America, for example,

747-416: A source of nutrition for the first three to seven days until they have the strength and mobility to find food. Juvenile tortoises often require a different balance of nutrients than adults, so may eat foods which a more mature tortoise would not. For example, the young of a strictly herbivorous species commonly will consume worms or insect larvae for additional protein. The number of concentric rings on

830-499: Is a member of the team making this classification. Pinzón Island When it was discovered that the central, small island of Pinzón had only 100–200 very old adults and no young tortoises had survived into adulthood for perhaps more than 70 years, the resident scientists initiated what would eventually become the Giant Tortoise Breeding and Rearing Program. Over the next 50 years, this program resulted in major successes in

913-435: Is detrimental in herbivorous species, and has been associated with shell deformities and other medical problems. Different tortoise species vary greatly in their nutritional requirements. Communication in tortoises is different from many other reptiles. Because they are restricted by their shell and short limbs, visual communication is not a strong form of communication in tortoises. Tortoises use olfactory cues to determine

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996-402: Is different from Wikidata All article disambiguation pages All disambiguation pages Tortoise Tortoises ( / ˈ t ɔːr t ə s . ɪ z / TOR -təs-iz ) are reptiles of the family Testudinidae of the order Testudines ( Latin for "tortoise"). Like other turtles , tortoises have a shell to protect from predation and other threats. The shell in tortoises

1079-506: Is extensive with the Aldabra giant tortoise , however taken as a subspecies, the Galápagos tortoise seems to average slightly larger, with weights in excess of 185 kg (408 lb) being slightly more commonplace. Weights in the larger bodied subspecies range from 272 to 317 kg (600 to 699 lb) in mature males and from 136 to 181 kg (300 to 399 lb) in adult females. However,

1162-636: Is generally hard, and like other members of the suborder Cryptodira , they retract their necks and heads directly backward into the shell to protect them. Tortoises can vary in size with some species, such as the Galápagos giant tortoise , growing to more than 1.2 metres (3.9 ft) in length, whereas others like the Speckled cape tortoise have shells that measure only 6.8 centimetres (2.7 in) long. Several lineages of tortoises have independently evolved very large body sizes in excess of 100 kg, including

1245-437: Is the largest living species of tortoise, and can weigh up to 417 kg (919 lb). They are also the largest extant terrestrial cold-blooded animals ( ectotherms ). With lifespans in the wild of over 100 years, it is one of the longest-lived vertebrates . Captive Galapagos tortoises can live up to 177 years. For example, a captive individual, Harriet , lived for at least 175 years. Spanish explorers, who discovered

1328-406: Is thought to have also been caused by predation by humans or human ancestors, as the tortoises themselves have no natural predators. Tortoise populations on at least three islands have become extinct in historical times due to human activities. Specimens of these extinct taxa exist in several museums and also are being subjected to DNA analysis. 12 subspecies of the original 14–15 survive in the wild;

1411-621: Is used to refer to a larger group of semiaquatic turtles than the restricted meaning in America. Australian usage is different from both American and British usage. Land tortoises are not native to Australia, and traditionally freshwater turtles have been called "tortoises" in Australia. Some Australian experts disapprove of this usage—believing that the term tortoises is "better confined to purely terrestrial animals with very different habits and needs, none of which are found in this country"—and promote

1494-1009: The Bahamas , the Greater Antilles (including Cuba and Hispaniola ), the Lesser Antilles , the Canary Islands , Malta , the Seychelles , the Mascarene Islands (including Mauritius and Reunion ), and Madagascar . Most of these tortoises were wiped out by human arrival. Many of these giant tortoises are not closely related (belonging to different genera such as Megalochelys , Chelonoidis , Centrochelys , Aldabrachelys , Cylindraspis , and Hesperotestudo ), but are thought to have independently evolved large body size through convergent evolution . Giant tortoises are notably absent from Australasia and many south Pacific islands, but

1577-723: The Galapagos giant tortoise and the Aldabra giant tortoise . They are usually diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals. Tortoises are the longest-living land animals in the world, although the longest-living species of tortoise is a matter of debate. Galápagos tortoises are noted to live over 150 years, but an Aldabra giant tortoise named Adwaita may have lived an estimated 255 years. In general, most tortoise species can live 80–150 years. Tortoises are placid and slow-moving, with an average walking speed of 0.2–0.5 km/h. Differences exist in usage of

1660-574: The Seychelles , and four from the Mascarenes . Günther hypothesized that all the giant tortoises descended from a single ancestral population which had spread by sunken land bridges . This hypothesis was later disproven by the understanding that the Galápagos, the atolls of Seychelles, and the Mascarene islands are all of recent volcanic origin and have never been linked to a continent by land bridges. Galápagos tortoises are now thought to have descended from

1743-405: The carapace and plastron . The plastron of a female tortoise often has a noticeable V-shaped notch below the tail which facilitates passing the eggs. Upon completion of the incubation period, a fully formed hatchling uses an egg tooth to break out of its shell. It digs to the surface of the nest and begins a life of survival on its own. They are hatched with an embryonic egg sac which serves as

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1826-461: The genomes of the long-lived tortoises, Lonesome George , the iconic last member of Chelonoidis abingdonii , and the Aldabra giant tortoise Aldabrachelys gigantea led to the detection of lineage-specific variants affecting DNA repair genes that might contribute to their long lifespan. Many species of tortoises are sexually dimorphic , though the differences between males and females vary from species to species. In some species, males have

1909-512: The second voyage of the Beagle in 1835, contributed to the development of his theory of evolution . Tortoise numbers declined from over 250,000 in the 16th century to a low of around 15,000 in the 1970s. This decline was caused by overexploitation of the subspecies for meat and oil, habitat clearance for agriculture, and introduction of non-native animals to the islands, such as rats, goats, and pigs. The extinction of most giant tortoise lineages

1992-421: The 17th century, Francesco Redi performed an experiment that involved removing the brain of a land tortoise, which then proceeded to live six months. Freshwater tortoises, when subjected to the same experiment, continued similarly, but did not live so long. Redi also cut the head off a tortoise entirely, and it lived for 23 days. Tortoises are found from southern North America to southern South America, around

2075-770: The 19th century had resulted in the complete eradication of all young tortoises. Black rats had been eating both tortoise eggs and hatchlings, effectively destroying the future of the tortoise population. Only the longevity of giant tortoises allowed them to survive until the Galápagos National Park, Island Conservation , Charles Darwin Foundation, the Raptor Center, and Bell Laboratories removed invasive rats in 2012. In 2013, heralding an important step in Pinzón tortoise recovery, hatchlings emerged from native Pinzón tortoise nests on

2158-465: The 19th century, and other giant tortoise radiations such as a Centrochelys radiation on the Canary Islands and another Chelonoidis radiation in the Caribbean were driven to extinction prior to that. The Galápagos Islands were discovered in 1535, but first appeared on the maps, of Gerardus Mercator and Abraham Ortelius , around 1570. The islands were named "Insulae de los Galopegos" (Islands of

2241-529: The 20th century, have resulted in thousands of captive-bred juveniles being released onto their ancestral home islands, and the total number of the subspecies is estimated to have exceeded 19,000 at the start of the 21st century. Despite this rebound, all surviving subspecies are classified as Threatened by the International Union for Conservation of Nature . The Galápagos tortoises are one of two insular radiations of giant tortoises that still survive to

2324-481: The Cerro Fatal tortoises were described as a distinct taxon, donfaustoi . Prior to the identification of this subspecies through genetic analysis, it was noted that there existed differences in shells between the Cerro Fatal tortoises and other tortoises on Santa Cruz. By classifying the Cerro Fatal tortoises into a new taxon, greater attention can be paid to protecting its habitat, according to Adalgisa Caccone, who

2407-801: The Galápagos radiation found that the level of divergence within both clades may have been significantly overestimated, and supported once again reclassifying all Galápagos tortoises as subspecies of a single species, C. niger . This was followed by the Turtle Taxonomy Working Group and the Reptile Database later that year. The taxonomic status of the various races is not fully resolved. C. n. nigra ( nominate subspecies ) C. n. abingdoni C. n. becki C. n. chathamensis C. n. darwini C. n. duncanensis C. n. hoodensis C. n. phantastica C. n. porteri C. n. vicina Modern DNA methods have revealed new information on

2490-481: The Galápagos tortoise was considered to belong to the genus Geochelone , known as 'typical tortoises' or 'terrestrial turtles'. In the 1990s, subgenus Chelonoidis was elevated to generic status based on phylogenetic evidence which grouped the South American members of Geochelone into an independent clade (branch of the tree of life ). This nomenclature has been adopted by several authorities. Within

2573-464: The Galápagos tortoises as a separate subspecies, which they named Testudo nigrita ("black tortoise"). The first systematic survey of giant tortoises was by the zoologist Albert Günther of the British Museum , in 1875. Günther identified at least five distinct populations from the Galápagos, and three from the Indian Ocean islands. He expanded the list in 1877 to six from the Galápagos, four from

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2656-484: The Mediterranean basin, across Eurasia to Southeast Asia, in sub-Saharan Africa, Madagascar, and some Pacific islands. They are absent from Australasia . They live in diverse habitats, including deserts, arid grasslands, and scrub to wet evergreen forests, and from sea level to mountains. Most species, however, occupy semiarid habitats. Many large islands are or were characterized by species of giant tortoises . Part of

2739-504: The San Diego Zoo and joined the breeding group. After 40 years' work reintroducing captive animals, a detailed study of the island's ecosystem has confirmed it has a stable, breeding population. Where once 15 were known, now more than 1,000 giant tortoises inhabit the island of Española. One research team has found that more than half the tortoises released since the first reintroductions are still alive, and they are breeding well enough for

2822-456: The Sierra Negra volcano, which was the first of the island's volcanoes to form. The tortoises then spread north to each newly created volcano, resulting in the populations living on Volcan Alcedo and then Volcan Darwin. Recent genetic evidence shows that these two populations are genetically distinct from each other and from the population living on Sierra Negra ( C. guentheri ) and therefore form

2905-691: The Tortoises) in reference to the giant tortoises found there. Initially, the giant tortoises of the Indian Ocean and those from the Galápagos were thought to be the same subspecies. Naturalists thought that sailors had transported the tortoises there. In 1676, the pre-Linnaean authority Claude Perrault referred to both subspecies as Tortue des Indes . In 1783, Johann Gottlob Schneider classified all giant tortoises as Testudo indica ("Indian tortoise"). In 1812, August Friedrich Schweigger named them Testudo gigantea ("gigantic tortoise"). In 1834, André Marie Constant Duméril and Gabriel Bibron classified

2988-522: The archipelago, 14-15 subspecies of Galápagos tortoises have been identified, although only 12 survive to this day. Five are found on separate islands; five of them on the volcanoes of Isabela Island . Several of the surviving subspecies are seriously endangered. A 13th subspecies, C. n. abingdonii from Pinta Island , is extinct since 2012. The last known specimen, named Lonesome George , died in captivity on 24 June 2012; George had been mated with female tortoises of several other subspecies, but none of

3071-420: The average incubation period are between 100 and 160.0 days. Egg-laying typically occurs at night, after which the mother tortoise covers her clutch with sand, soil, and organic material. The eggs are left unattended, and depending on the species, take from 60 to 120 days to incubate. The size of the egg depends on the size of the mother and can be estimated by examining the width of the cloacal opening between

3154-610: The back legs four. The discoverer of the Galápagos Islands, Fray Tomás de Berlanga, Bishop of Panama, wrote in 1535 of "such big tortoises that each could carry a man on top of himself." Naturalist Charles Darwin remarked after his trip three centuries later in 1835, "These animals grow to an immense size ... several so large that it required six or eight men to lift them from the ground". The largest recorded individuals have reached weights of over 400 kg (880 lb) and lengths of 1.87 meters (6.1 ft). Size overlap

3237-488: The carapace, much like the cross-section of a tree , can sometimes give a clue to how old the animal is, but, since the growth depends highly on the accessibility of food and water, a tortoise that has access to plenty of forage (or is regularly fed by its owner) with no seasonal variation will have no noticeable rings. Moreover, some tortoises grow more than one ring per season, and in some others, due to wear, some rings are no longer visible. Tortoises generally have one of

3320-587: The care of the Tongan royal family until its death by natural causes on May 19, 1965, at the age of 188. The Alipore Zoo in India was the home to Adwaita , which zoo officials claimed was the oldest living animal until its death on March 23, 2006. Adwaita (also spelled Addwaita) was an Aldabra giant tortoise brought to India by Lord Wellesley, who handed it over to the Alipur Zoological Gardens in 1875 when

3403-443: The colonization of islands. Galápagos tortoises possess two main shell forms that correlate with the biogeographic history of the subspecies group. They exhibit a spectrum of carapace morphology ranging from "saddleback" (denoting upward arching of the front edge of the shell resembling a saddle) to "domed" (denoting a rounded convex surface resembling a dome). When a saddleback tortoise withdraws its head and forelimbs into its shell,

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3486-446: The common terms turtle , tortoise, and terrapin , depending on the variety of English being used; usage is inconsistent and contradictory. These terms are common names and do not reflect precise biological or taxonomic distinctions. The American Society of Ichthyologists and Herpetologists uses "turtle" to describe all species of the order Testudines, regardless of whether they are land-dwelling or sea-dwelling, and uses "tortoise" as

3569-528: The constellation of Pisces See also [ edit ] Tortoise (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Testudo . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Testudo&oldid=997614195 " Category : Disambiguation pages Hidden categories: Short description

3652-467: The differences between the populations (sometimes called races ) from different islands and volcanoes, captive collections in zoos were indiscriminately mixed. Fertile offspring resulted from pairings of animals from different races. However, captive crosses between tortoises from different races have lower fertility and higher mortality than those between tortoises of the same race, and captives in mixed herds normally direct courtship only toward members of

3735-750: The distantly related meiolaniid turtles are thought to have filled the same niche. Giant tortoises are also known from the Oligocene - Pliocene of mainland North America , South America , Europe , Asia , and Africa , but are all now extinct, which is also attributed to human activity. Tortoises are generally considered to be strict herbivores , feeding on grasses, weeds, leafy greens, flowers, and some fruits. However, hunting and eating of birds has been observed on occasion. Pet tortoises typically require diets based on wild grasses, weeds, leafy greens and certain flowers. Certain species consume worms or insects and carrion in their normal habitats. Too much protein

3818-496: The dominant large herbivores on many islands due to their low metabolic rate and reduced need for fresh water compared to mammals. Today there are only two living species of giant tortoises, the Aldabra giant tortoise on Aldabra Atoll and the dozen subspecies of Galapagos giant tortoise found on the Galapagos Islands . However, until recently giant tortoises could be found on nearly every major island group, including

3901-413: The eggs from these pairings hatched. The subspecies inhabiting Floreana Island ( C. niger ) is thought to have been hunted to extinction by 1850, only 15 years after Charles Darwin 's landmark visit of 1835, when he saw shells, but no live tortoises there. However, recent DNA testing shows that an intermixed, non-native population currently existing on the island of Isabela is of genetic resemblance to

3984-419: The existence of 15 subspecies. Van Denburgh's list still guides the taxonomy of the Galápagos tortoise, though now 10 populations are thought to have existed. The current specific designation of niger , formerly feminized to nigra ("black"— Quoy & Gaimard , 1824b ) was resurrected in 1984 after it was discovered to be the senior synonym (an older taxonomic synonym taking historical precedence) for

4067-413: The extinct subspecies of Floreana ( C. n. niger )—a subspecies known only from subfossil remains. Some tortoises from Isabela were found to be a partial match for the genetic profile of Floreana specimens from museum collections, possibly indicating the presence of hybrids from a population transported by humans from Floreana to Isabela, resulting either from individuals deliberately transported between

4150-585: The island and the Galápagos National Park successfully returned 118 hatchlings to their native island home. Partners returned to Pinzón Island in late 2014 and continued to observe hatchling tortoises (now older), indicating that natural recruitment is occurring on the island unimpeded. They also discovered a snail subspecies new to science. These exciting results highlight the conservation value of this important management action. In early 2015, after extensive monitoring, partners confirmed that Pinzón and Plaza Sur Islands are now both rodent-free. Española Island On

4233-419: The island for a long time after its sighting, leading to suggestions that the specimen was an artificial introduction from elsewhere. Fernandina has neither human settlements nor feral mammals, so if this subspecies ever did exist, its extinction would have been by natural means, such as volcanic activity. Nevertheless, there have occasionally been reports from Fernandina. In 2019, an elderly female specimen

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4316-587: The islands in the 16th century, named them after the Spanish galápago , meaning "tortoise". Galápagos tortoises are native to seven of the Galápagos Islands . Shell size and shape vary between subspecies and populations. On islands with humid highlands, the tortoises are larger, with domed shells and short necks; on islands with dry lowlands, the tortoises are smaller, with "saddleback" shells and long necks. Charles Darwin 's observations of these differences on

4399-511: The islands, or from individuals thrown overboard from ships to lighten the load. Nine Floreana descendants have been identified in the captive population of the Fausto Llerena Breeding Center on Santa Cruz; the genetic footprint was identified in the genomes of hybrid offspring. This allows the possibility of re-establishing a reconstructed subspecies from selective breeding of the hybrid animals. Furthermore, individuals from

4482-454: The limited evidence of bone fragments (but no shells, the most durable part) of 14 individuals, old eggs, and old dung found on the island in 1905–06. The island has never been inhabited by man nor had any introduced predators, but reports have been made of whalers hauling tortoises off the island. Later genetic studies of the bone fragments indicate that the Santa Fe subspecies was distinct, and

4565-409: The linking of nigra with the extinct Floreana subspecies. Later, Pritchard deemed it convenient to accept this designation, despite its tenuousness, for minimal disruption to the already confused nomenclature of the subspecies. The even more senior subspecies synonym of californiana ("californian" – Quoy & Gaimard , 1824a ) is considered a nomen oblitum ("forgotten name"). Previously,

4648-543: The longest lifespans of any animal, and some individuals are known to have lived longer than 150 years. Because of this, they symbolize longevity in some cultures, such as Chinese culture . The oldest tortoise ever recorded, and one of the oldest individual animals ever recorded, was Tu'i Malila , which was presented to the Tongan royal family by the British explorer James Cook shortly after its birth in 1777. Tu'i Malila remained in

4731-540: The mascot of University of Maryland, College Park Testudo (genus) , a genus in the tortoise family of turtles Testudo formation , a Roman military tactic which involved a formation of soldiers using their shields to form a tortoise-shell-like protective cover against enemy weapons Testudo, the Latin variant of the Greek chelys harp, involving a sound-box made from a tortoise shell Testudo, an obsolete constellation now in

4814-416: The members of the genus Terrapene dwell on land, yet are referred to as box turtles rather than tortoises. British usage, by contrast, tends not to use "turtle" as a generic term for all members of the order, and also applies the term "tortoises" broadly to all land-dwelling members of the order Testudines, regardless of whether they are actually members of the family Testudinidae. In Britain, terrapin

4897-467: The modern day; the other is Aldabrachelys gigantea of Aldabra and the Seychelles in the Indian Ocean , 700 km (430 mi) east of Tanzania . While giant tortoise radiations were common in prehistoric times, humans have wiped out the majority of them worldwide; the only other radiation of tortoises to survive to historic times, Cylindraspis of the Mascarenes , was driven to extinction by

4980-431: The population to progress onward, unaided. In January 2020, it was widely reported that Diego, a 100-year-old male tortoise, resurrected 40% of the tortoise population on the island and is known as the "Playboy Tortoise". Fernandina Island The C. n. phantasticus subspecies from Fernandina was originally known from a single specimen—an old male from the voyage of 1905–06. No other tortoises or remains were found on

5063-434: The rear shell. The brain of a tortoise is extremely small. Red-footed tortoises, from Central and South America, do not have an area in the brain called the hippocampus , which relates to emotion, learning, memory and spatial navigation. Studies have shown that red-footed tortoises may rely on an area of the brain called the medial cortex for emotional actions, an area that humans use for actions such as decision making. In

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5146-403: The reason for this is that tortoises are good at oceanic dispersal . Despite being unable to swim, tortoises are able to survive long periods adrift at sea because they can survive months without food or fresh water. Tortoises have been known to survive oceanic dispersals of more than 740 km. Once on islands tortoises faced few predators or competitors and could grow to large sizes and become

5229-481: The recovery of giant tortoise populations throughout the archipelago. In 1965, the first tortoise eggs collected from natural nests on Pinzón Island were brought to the Charles Darwin Research Station, where they would complete the period of incubation and then hatch, becoming the first young tortoises to be reared in captivity. The introduction of black rats onto Pinzón sometime in the latter half of

5312-468: The regions of Cerro Montura, Cerro Fatal, and La Caseta. Although traditionally grouped into a single subspecies ( C. n. porteri ), the lineages are all more closely related to tortoises on other islands than to each other: Cerro Montura tortoises are most closely related to C. n. duncanensis from Pinzón, Cerro Fatal to C. n. chathamensis from San Cristóbal, and La Caseta to the four southern races of Isabela as well as Floreana tortoises. In 2015,

5395-407: The relationships between the subspecies: Isabela Island The five populations living on the largest island, Isabela, are the ones that are the subject of the most debate as to whether they are true subspecies or just distinct populations of a subspecies. It is widely accepted that the population living on the northernmost volcano, Volcan Wolf, is genetically independent from the four populations to

5478-404: The same race. The valid scientific names of each of the individual populations are not universally accepted, and some researchers still consider each subspecies to be distinct species. Prior to 2021, all subspecies were classified as distinct species from one another, but a 2021 study analyzing the level of divergence within the extinct West Indian Chelonoidis radiation and comparing it to

5561-544: The search for an appropriate mate for Lonesome George , which had been penned with females from Isabela. Hope was bolstered by the discovery of a C. n. abingdonii hybrid male in the Volcán Wolf population on northern Isabela, raising the possibility that more undiscovered living Pinta descendants exist. Santa Cruz Island Mitochondrial DNA studies of tortoises on Santa Cruz show up to three genetically distinct lineages found in nonoverlapping population distributions around

5644-963: The sex of other tortoises so that they can find a potential mate. Tactile communication is important in tortoises during combat and courtship. In both combat and courtship, tortoises use ramming to communicate with other individuals. This species list largely follows Turtle Taxonomy Working Group (2021) and the Turtle Extinctions Working Group (2015). Family Testudinidae Batsch 1788 A molecular phylogeny of tortoises, following Le et al. (2006: 525): Ergilemys Manouria Gopherus Indotestudo Testudo Malacochersus Centrochelys sulcata Geochelone platynota Geochelone elegans Chersina Homopus Stigmochelys Psammobates Aldabrachelys Pyxis Astrochelys radiata Astrochelys yniphora Kinixys Chelonoidis A separate phylogeny via mtDNA analysis

5727-442: The shells of these slow-moving animals. Tortoises keep a characteristic scute (shell segment) pattern on their shells throughout life, though the annual growth bands are not useful for determining age because the outer layers are worn off with time. A tortoise can withdraw its head, neck, and fore limbs into its shell for protection. The legs are large and stumpy, with dry, scaly skin and hard scales . The front legs have five claws,

5810-554: The size is variable across the islands and subspecies; those from Pinzón Island are relatively small with a maximum known weight of 76 kg (168 lb) and carapace length of approximately 61 cm (24 in) compared to 75 to 150 cm (30 to 59 in) range in tortoises from Santa Cruz Island . The tortoises' gigantism was probably a trait useful on continents that was fortuitously helpful for successful colonisation of these remote oceanic islands rather than an example of evolved insular gigantism . Large tortoises would have

5893-496: The south and is therefore a separate subspecies. It is thought to be derived from a different colonization event than the others. A colonization from the island of Santiago apparently gave rise to the Volcan Wolf subspecies ( C. n. becki ) while the four southern populations are believed to be descended from a second colonization from the more southerly island of Santa Cruz. Tortoises from Santa Cruz are thought to have first colonized

5976-429: The southern island of Española, only 14 adult tortoises were found, two males and 12 females. The tortoises apparently were not encountering one another, so no reproduction was occurring. Between 1963 and 1974, all 14 adult tortoises discovered on the island were brought to the tortoise center on Santa Cruz and a tortoise breeding program was initiated. In 1977, a third Española male tortoise was returned to Galapagos from

6059-644: The subspecies C. n. vandenburghi (Alcedo) and C. n. microphyes (Darwin). The fifth population living on the southernmost volcano ( C. n. vicina ) is thought to have split off from the Sierra Negra population more recently and is therefore not as genetically different as the other two. Isabela is the most recently formed island tortoises inhabit, so its populations have had less time to evolve independently than populations on other islands, but according to some researchers, they are all genetically different and should each be considered as separate subspecies. Floreana Island Phylogenetic analysis may help to "resurrect"

6142-414: The subspecies native to Floreana, suggesting that C. niger has not gone entirely extinct. The existence of the C. n. phantastica subspecies of Fernandina Island was disputed, as it was described from a single specimen that may have been an artificial introduction to the island; however, a live female was found in 2019, likely confirming the subspecies' validity. Prior to widespread knowledge of

6225-426: The subspecies on the islands of San Cristóbal ( C. n. chathamensis ) and Española ( C. n. hoodensis ) which lie over 300 km (190 mi) away, rather than that on the neighbouring island of Isabela as previously assumed. This relationship is attributable to dispersal by the strong local current from San Cristóbal towards Pinta. This discovery informed further attempts to preserve the C. n. abingdonii lineage and

6308-461: The subspecies possibly are still extant. Genetic analysis from a sample of tortoises from Volcan Wolf found 84 first-generation C. n. niger hybrids, some less than 15 years old. The genetic diversity of these individuals is estimated to have required 38 C. n. niger parents, many of which could still be alive on Isabela Island. Pinta Island The Pinta Island subspecies ( C. n. abingdonii , now extinct) has been found to be most closely related to

6391-443: The then commonly used subspecies name of elephantopus ("elephant-footed" – Harlan , 1827 ). Quoy and Gaimard's Latin description explains the use of nigra: "Testudo toto corpore nigro" means "tortoise with completely black body". Quoy and Gairmard described nigra from a living specimen, but no evidence indicates they knew of its accurate provenance within the Galápagos – the locality was in fact given as California. Garman proposed

6474-410: The use of the term "freshwater turtle" to describe Australia's primarily aquatic members of the order Testudines because it avoids misleading use of the word "tortoise" and also is a useful distinction from marine turtles. Most species of tortoises lay small clutch sizes, seldom exceeding 20 eggs, and many species have clutch sizes of only 1–2 eggs. Incubation is characteristically long in most species,

6557-655: The zoo was set up. West Bengal officials said records showed Adwaita was at least 150 years old, but other evidence pointed to 250. Adwaita was said to be the pet of Robert Clive . Harriet was a resident at the Australia Zoo in Queensland from 1987 to her death in 2006; she was believed to have been brought to England by Charles Darwin aboard the Beagle and then on to Australia by John Clements Wickham . Harriet died on June 23, 2006, just shy of her 176th birthday. Timothy ,

6640-474: Was finally discovered on Fernandina and transferred to a breeding center, and trace evidence found on the expedition indicates that more individuals likely exist in the wild. It has been theorized that the rarity of the subspecies may be due to the harsh habitat it survives in, such as the lava flows that are known to frequently cover the island. The extinct Santa Fe subspecies has not yet been described and thus has no binomial name , having been identified from

6723-433: Was found by Kehlmaier et al. (2021): Gal%C3%A1pagos tortoise 12 extant subspecies, 2 extinct subspecies See section The Galápagos tortoise or Galápagos giant tortoise ( Chelonoidis niger ) is a very large species of tortoise in the genus Chelonoidis (which also contains three smaller species from mainland South America ). The species comprises 15 subspecies (13 extant and 2 extinct ). It

6806-499: Was most closely related to C. n. hoodensis . A population of C. n. hoodensis has since been reintroduced to and established on the island to fill in the ecological role of the Santa Fe tortoise. Subspecies of doubtful existence The purported Rábida Island subspecies ( C. n. wallacei ) was described from a single specimen collected by the California Academy of Sciences in December 1905, which has since been lost. This individual

6889-418: Was probably an artificial introduction from another island that was originally penned on Rábida next to a good anchorage, as no contemporary whaling or sealing logs mention removing tortoises from this island. The tortoises have a large bony shell of a dull brown or grey color. The plates of the shell are fused with the ribs in a rigid protective structure that is integral to the skeleton. Lichens can grow on

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