''Chelonoidis niger'' (the

Galápagos tortoise 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 subsp ...

) is a tortoise species

endemic Endemism is the state of a species being found only 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 foun ...

to the

Galápagos Islands The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of sli ...

. It includes at least 14, and possibly up to 16,

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

. Only 12 subspecies now exist: one on each of the islands of

Santiago Santiago (, ; ), also known as Santiago de Chile (), is the capital and largest city of Chile and one of the largest cities in the Americas. It is located in the country's central valley and is the center of the Santiago Metropolitan Regi ...

, San Cristóbal, Pinzón, Española, and Fernandina; two on Santa Cruz; one on each of the five main volcanoes of the largest island,

Isabela Isabela may refer to: People with the given name * Isabela Boscov, Brazilian film critic * Isabela Corona (1913–1993), Mexican actress * Isabela Garcia (born 1967), Brazilian actress * Isabela Moraes (born 1980), Brazilian synchronized swimmer ...

(

Wolf The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a Canis, canine native to Eurasia and North America. More than thirty subspecies of Canis lupus, subspecies of ''Canis lupus'' have been recognized, includin ...

, Darwin,

Alcedo ''Alcedo'' is a genus of birds in the kingfisher subfamily Alcedininae. The genus was introduced by Carl Linnaeus in 1758 in the 10th edition of Systema Naturae, 10th edition of his ''Systema Naturae''. The type species is the common kingfisher ...

Sierra Negra Sierra Negra (also, and perhaps more properly, Cerro La Negra) is an extinct volcano located in the Mexico, Mexican state of Puebla, close to the border with Veracruz. At officially above sea level, it is the fifth-highest peak in Mexico. Sie ...

, and Cerro Azul); and one, '' abingdoni'' from Pinta Island, which is considered

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

as of June 24, 2012. The subspecies inhabiting

Floreana Island Floreana Island () is a southern island in Ecuador's Galápagos Archipelago. The island has an area of . It was formed by volcanic eruption. The island's highest point is Cerro Pajas at , which is also the highest point of the volcano like most ...

(''Chelonoidis niger niger'') is thought to have been hunted to extinction by 1850, only years after

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

's landmark visit of 1835 in which he saw carapaces but no live tortoises on the island; however, hybrid tortoises with ''C. n. niger'' ancestry still exist in the modern day. Biological taxonomy is not fixed, and placement of taxa is reviewed as a result of new research. The current categorization of subspecies of ''Chelonoidis niger'' is shown below. Also included are synonyms, which are now discarded duplicate or incorrect namings. Common names are given but may vary, as they have no set meaning. Prior to the 2000s, all members of this group were classified as subspecies in a single species, ''Chelonoidis niger''. From the 2000s until 2021, the individual subspecies were instead classified as distinct species. However, a 2021 study analyzing the level of divergence within the extinct West Indian ''Chelonoidis'' radiation and comparing it to 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 The Turtle Taxonomy Working Group (TTWG) is an informal working group of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group (TFTSG). It is composed of a number of leading turtle taxonomists, with varying participation by individual partici ...

and the

Reptile Database The Reptile Database is a scientific database that collects taxonomic information on all living reptile species (i.e. no fossil species such as dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared ...

List of subspecies

Disputed subspecies

References