The Chaco tortoise (''Chelonoidis chilensis''), also known commonly as the Argentine tortoise, the Patagonian tortoise, or the southern wood tortoise, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
tortoise
Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a turtle shell, shell to protect from predation and other threats. The shell in tortoises is generally hard, ...
in the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Testudinidae. The species is
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 elsew ...
to
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
.
Geographic range
The Chaco tortoise is mainly found in
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
, but also in
Bolivia
, image_flag = Bandera de Bolivia (Estado).svg
, flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center
, flag_alt2 = 7 × 7 square p ...
and
Paraguay
Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...
, mainly within the Chaco and Monte ecoregions. Its distribution is mainly limited by temperature-related variables, and precipitation in the reproductive period.
Taxonomy
The
scientific name
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
for this species, ''Chelonoidis chilensis'', is misleading because it is not native to
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
. It occurs mainly in Argentina, Bolivia and neighboring Paraguay. When the species was first described by
Gray
Grey (more common in British English) or gray (more common in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning literally that it is "without color", because it can be composed o ...
in 1870, he mistakenly thought that
Mendoza was in Chile instead of Argentina (
the city was transfer in 1776), thus the misnomer.
Sclater corrected Gray's mistake in the same year. However, the rules of
nomenclature
Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. The principles of naming vary from the relatively informal naming conventions, conventions of everyday speech to the i ...
give precedence to the name ''chilensis'', even though it was based on an erroneous assumption, and the name has persisted.
Description
The
carapace
A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...
of ''C. chilensis'' can measure up to 43.3 cm (but usually less than 25 cm) in a straight line, and may be either totally yellowish brown or have dark-brown to black rings surrounding a tan center on each
scute
A scute or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterior po ...
. Specimens found farther south tend to be much larger than those found in farther north populations. The rim of the shell is slightly serrated and has a dark wedge of pigment at the back edge of each scute. The
plastron may be uniformly yellowish-brown or have a dark triangular wedge along the seams of each scute. The head, limbs and tail are greyish to yellowish-brown, with the front of each forelimb covered with large, angular scales and each thigh featuring several enlarged
tubercles
In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal.
In plants
A tubercle is generally a wart-like projection ...
.
Diet
Like all tortoise species, the Chaco tortoise is primarily herbivorous, consuming grasses, shrubs, fruits, and cactus pads.
Species status
There is only one recognized species.
[ However, some researchers believe ''C. chilensis'' should be divided into three species: ''C. chilensis'', ''C. petersi'', and ''C. donosobarrosi''. Some support ''C. donosobarrosi'' as a subspecies (''C. chilensis donosobarrosi''). There is research to indicate that it may qualify as a separate species, while ''C. petersi'' may just be a variant of ''C. chilensis'', the variances being clinal variations in adjacent populations.][ Historically, these have been viewed as separate taxa, with little work done to confirm or deny it. Subsequent molecular analysis has found little to no genetic variation.
]
Etymology
The specific name (or subspecific name
In zoological nomenclature, a subspecific name is the third part of a trinomen. In zoology there is only one rank below that of species, namely "subspecies".
In botanical nomenclature, there are several levels of subspecific names, such as ''vari ...
), ''donosobarrosi'', is in honor of Chilean herpetologist Roberto Donoso-Barros
Roberto Donoso-Barros (October 5, 1921 – August 2, 1975) was a Chilean botanist, naturalist, and herpetologist.
Early life and education
Donoso-Barros was born in Santiago, Chile. He attended the University of Chile in Santiago, earning hi ...
,[ Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Geochelone donosobarrosi'', p. 74).] and ''petersi'' is in honor of American herpetologist James A. Peters
James Arthur Peters (July 13, 1922 – December 18, 1972) was an American herpetologists and zoogeographer.
He was born in Durant, Iowa; raised in Greenup, Illinois. He studied at the University of Michigan and obtained his Ph.D. in biology i ...
.
References
;Bibliography
*
* Boulenger GA (1889). ''Catalogue of the Chelonians, Rhynchocephalians, and Crocodiles in the British Museum (Natural History). New Edition.'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). x + 311 pp. + Plates I-III. ("''Testudo argentina''", p. 159).
* Gray JE (1870). "Notice of a new Chilian icTortoise (''Testudo chilensis'')". ''Ann. Mag. Nat. Hist., Fourth Series'' 6: 190. ''Testudo (Gopher) chilensis''", new species
{{Taxonbar, from1=Q5066111, from2=Q1074424
Chelonoidis
Reptiles of Argentina
Reptiles of Bolivia
Reptiles of Paraguay
Reptiles described in 1870
Taxa named by John Edward Gray