Trachylepis tschudii
Encyclopedia

Trachylepis tschudii is an enigmatic skink
Skink
Skinks are lizards belonging to the family Scincidae. Together with several other lizard families, including Lacertidae , they comprise the superfamily or infraorder Scincomorpha...

, purportedly from Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

. First described in 1845 on the basis of a single specimen, it may be the same as the Noronha skink
Noronha skink
The Noronha skink is a species of skink from the island of Fernando de Noronha off northeastern Brazil. It is covered with dark and light spots on the upperparts and is usually about 7 to 10 cm in length. The tail is long and muscular, but breaks off easily...

 (T. atlantica) from Fernando de Noronha
Fernando de Noronha
Fernando de Noronha is an archipelago of 21 islands and islets in the Atlantic Ocean, offshore from the Brazilian coast. The main island has an area of and had a population of 3,012 in the year 2010...

, off northeastern Brazil. T. tschudii represents one of two doubtful records of the otherwise African genus Trachylepis
Trachylepis
Trachylepis is a skink genus in the subfamily Lygosominae found mainly in Africa. Its members were formerly included in the "wastebin taxon" Mabuya, and for some time in Euprepis. As defined today, Trachylepis contains the clade of Afro-Malagasy mabuyas. The genus also contains a species from the...

on mainland South America; the other is T. maculata
Trachylepis maculata
Trachylepis maculata is a species of skink in the genus Trachylepis recorded from Demerara in Guyana, northern South America. It is placed in the genus Trachylepis, which is otherwise mostly restricted to Africa, and its type locality may be in error. It is an unstriped, olive-brown, grayish...

from Guyana.

The only specimen, the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

, is mostly brownish above, with dark and light spots, and white below. The snout-to-vent length is 83 mm (3.3 in). Several features of the scale
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...

s align it with Trachylepis over the related American genus Mabuya.

Taxonomy

In 1845, Swiss zoologist Johann Jakob von Tschudi
Johann Jakob von Tschudi
Johann Jakob von Tschudi was a Swiss naturalist and explorer.Tschudi was born in Glarus, and studied natural sciences and medicine at the universities of Neuchâtel, Leiden and Paris. In 1838 he travelled to Peru, where he remained for five years exploring and collecting plants in the Andes...

 described the new species Trachylepis (Xystrolepis) punctata among other species he had collected in Peru. The species was recorded as being from the "forest region" (Amazonia) of Peru and was known from a single specimen, the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

. In 1887, G.A. Boulenger placed it at an uncertain position within the genus Mabuia
Mabuya
Mabuya is a genus of long-tailed skinks nowadays restricted to species from the Americas. The American mabuyas are primarily carnivorous, though many are omnivorous. Formerly, many Old World species were placed here, as Mabuya was a kind of "wastebasket taxon"...

, which included Tschudi's Trachylepis. In a 1907 reappraisal of some of Tschudi's reptiles and amphibians, J. Roux redescribed punctata under the name "Mabuia punctata", but did not comment on its affinities. In 1935, E.R. Dunn reviewed some American Mabuya and commented that he was unable to tell the identity of punctata, but that it probably was not a true Mabuya.

Writing in 1946, H. Travassos considered Tschudi's punctata to be identical to the Noronha skink
Noronha skink
The Noronha skink is a species of skink from the island of Fernando de Noronha off northeastern Brazil. It is covered with dark and light spots on the upperparts and is usually about 7 to 10 cm in length. The tail is long and muscular, but breaks off easily...

 (then known as Mabuya punctata), a species otherwise known only from Fernando de Noronha
Fernando de Noronha
Fernando de Noronha is an archipelago of 21 islands and islets in the Atlantic Ocean, offshore from the Brazilian coast. The main island has an area of and had a population of 3,012 in the year 2010...

, a small archipelago off northeastern Brazil. On the basis of its geographic origin, J. Peters and R. Donoso-Barros preferred to place it with one of the Mabuya species of Amazonia and classified it as a junior synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 of Mabuya mabouya
Mabuya mabouya
Mabuya mabouya is a species of skink found on certain islands in the Caribbean. It has shiny, bronze-colored skin, with a pair of light stripes that run along its upper flanks....

. In reviewing the nomenclature of the Noronha skink, P. Mausfeld and D. Vrcibradic noted in 2002 that Tschudi's name was preoccupied within Mabuya, making it unavailable for use as a valid name. They were unable to examine the holotype and therefore did not comment on its affinities. In the same year, Mausfeld and others split the genus Mabuya, retaining most American species in Mabuya but placing the African species and the Noronha skink in a separate genus Euprepis; the latter name was later corrected to Trachylepis
Trachylepis
Trachylepis is a skink genus in the subfamily Lygosominae found mainly in Africa. Its members were formerly included in the "wastebin taxon" Mabuya, and for some time in Euprepis. As defined today, Trachylepis contains the clade of Afro-Malagasy mabuyas. The genus also contains a species from the...

.

In 2009, A. Miralles and others reviewed Tschudi's species and re-examined the holotype. Like Mausfeld and Vrcibradic, they noted that the name punctata is preoccupied; earlier uses of the name in Trachylepis include Lacerta punctata Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...

, 1758, which they consider a synonym of Trachylepis homalocephala
Trachylepis homalocephala
The Red-sided Skink is a small, slender species of skink in the subfamily Lygosominae. It is indigenous to Southern Africa, where it typically occurs in coastal thicket and leaf litter along the South African coast - from Cape Town, eastwards along the coast as far as Mozambique...

from South Africa, and Tiliqua punctata J.E. Gray
John Edward Gray
John Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray ....

, 1839, an earlier name for the Noronha skink. (The former was assigned to Lygosoma punctatum, a member of another skink genus, by Bauer in 2003.) Miralles and coworkers proposed a new name
Nomen novum
In biological nomenclature, a nomen novum , new replacement name is a technical term...

, Trachylepis tschudii, to replace Tschudi's name punctata; the new name honors Tschudi, who first described the animal. They assigned it to the genus Trachylepis, rather than Mabuya, on the basis of several characters of the external anatomy which it shares with the former, but were unable to resolve its placement within Trachylepis. It is distinct from T. maculata
Trachylepis maculata
Trachylepis maculata is a species of skink in the genus Trachylepis recorded from Demerara in Guyana, northern South America. It is placed in the genus Trachylepis, which is otherwise mostly restricted to Africa, and its type locality may be in error. It is an unstriped, olive-brown, grayish...

, a species recorded from Guyana that represents another doubtful mainland South American record of Trachylepis. They considered three hypotheses: (1) T. tschudii is a real, but very rare species from Amazonia; (2) T. tschudii is actually from somewhere in the Old World, but its origin was wrongly recorded; and (3) T. tschudii represents the same species as the Noronha skink, and it either represents an otherwise unknown Amazonian population of that species or actually comes from Fernando de Noronha and was mislabeled. Considering the close similarity between T. tschudii and the Noronha skink, they considered the third hypothesis to be most likely.

Description

The holotype and only known specimen, which is in very poor condition, is preserved in the Museum d'Histoire Naturel de Neuchâtel as specimen MHNN 91.2426. It has five auricular lobules in front of the ears on each side of the head, 39 rows of scale
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...

s around the midbody, keels on its dorsal scales, and the third supraocular scale in contact with the frontal scale, all characters which align it with Trachylepis rather than Mabuya. The other putative mainland South American Trachylepis, T. maculata, has five instead of three keels, 32 to 34 midbody scales, and separated parietal scales. T. tschudii agrees wti the Noronha skink in size, coloration, numbers of scales, and discrete characters, such as having the supranasal, parietal, and prefrontal scales all in contact.

The muzzle is narrow and long. The lower eyelid contains a large, transparent disk. The head is olive-brown. There are black scales with a white border between the eyes and the ears. The body is somewhat darker than the head and covered with irregular black and white spots above and is bluish white below. The limbs are yellowish white below. The tail is light brown above, but has two rows of darker spots, and yellowish white below. Snout-to-vent length is 83 mm (3.3 in), head length 10 mm (0.39 in), head width 6.5 mm (0.26 in), length of the body 33 mm (1.3 in), length of the forelimb 15 mm (0.59 in), length of the hindlimb 23 mm (0.91 in), and length of the (incomplete) tail 40 mm (1.6 in).

Literature cited

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