The Chaco tortoise (''Chelonoidis chilensis''), also known commonly as the Argentine tortoise, the Patagonian tortoise, or the southern wood tortoise, is a
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
tortoise
Tortoises ( ) 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 is generally hard, and like o ...
in the
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Testudinidae
Tortoises ( ) 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 is generally hard, and like ot ...
. The species is
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
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
.
Geographic range
The Chaco tortoise is mainly found in
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
, but also in
Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...
and
Paraguay
Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...
, 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 (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...
for this species, ''Chelonoidis chilensis'', is misleading because it is not native to
Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
. It occurs mainly in Argentina, Bolivia and neighboring Paraguay. When the species was first described by
Gray
Grey (more frequent in British English) or gray (more frequent in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning that it has no chroma. It is the color of a cloud-covered s ...
in 1870, he mistakenly thought that
Mendoza was in Chile instead of Argentina (
the city was transfer in 1776), thus the misnomer.
Sclater
Philip Lutley Sclater (4 November 1829 – 27 June 1913) was an English lawyer and zoologist. In zoology, he was an expert ornithologist, and identified the main zoogeographic regions of the world. He was Secretary of the Zoological Society ...
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 theoretical field studying nomenclature is sometimes referred to as ''onymology'' or ''taxonymy'' ). The principl ...
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 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 tortoises, the unde ...
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'' "Scutum (shield), 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 Bird anatomy#Scales, birds. The ter ...
. 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
The turtle shell is a shield for the ventral and dorsal parts of turtles (the Order (biology), order Testudines), completely enclosing all the turtle's vital organs and in some cases even the head. It is constructed of modified bony elements such ...
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, b ...
.
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 Specific name may refer to:
* in Database management systems, a system-assigned name that is unique within a particular database
In taxonomy, either of these two meanings, each with its own set of rules:
* Specific name (botany), the two-part (bino ...
(or subspecific name
In biology, trinomial nomenclature is the system of names for taxa below the rank of species. These names have three parts. The usage is different in zoology and botany.
In zoology
In zoological nomenclature, a trinomen (), trinominal name, or ...
), ''donosobarrosi'', is in honor of Chilean herpetologist Roberto Donoso-Barros
Roberto Donoso-Barros (October 5, 1921 – August 2, 1975) was a Chilean zoologist, naturalist, and herpetologist. Jaime Péfaur listed his birth year as 1922.
Early life and education
Donoso-Barros was born in Santiago, Chile. He attended the ...
,[ 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.
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