De Winton's gold mole
| De Winton's gold mole | ||||||||||||
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| Cryptochloris wintoni | ||||||||||||
| ( Broom , 1907) |
De Winton's gold mole ( Cryptochloris wintoni ) is a rarely explored species of the gold mole family (Chrysochloridae). It is only known from three specimens that come from a single location near Port Nolloth in southwest Africa . The animals inhabit sandy habitats , nothing more is known about their way of life. With their diamond-shaped body, the outwardly invisible ears and tail as well as the powerful grave claws, however, they are adapted to an underground way of life. The stock is classified as critically endangered, which is primarily due to the habitat that has been heavily modified by mining , and De Winton's gold mole may already have become extinct. The species was first described in 1907.
features
Habitus
De Winton's gold mole is a small species of gold mole that is similar in size and coat color to the desert gold mole ( Eremitalpa granti ). Size specifications are only known from two specimens with head-to-torso lengths of 8.6 and 9.2 cm, respectively. There are no data on body weight, and the extent of any gender dimorphism is also unknown. The body is short and diamond-shaped, there is no tail or external auricles. The fur on the back has a light slate-gray color with a yellowish tinge that becomes more intense on the forehead, cheeks and lips. The individual hairs are whitish, gray at the base and distinctly fawn brown at the top. The ventral side is slightly lighter than the fur on the back, with the tips of the hair being whitish here. The typical leathery nose pad of the golden mole is about 4 mm long and 8 mm wide, the corners are rounded, the front area, which is used for digging, rises slightly more prominently than the Cape golden mole ( Chrysochloris asiatica ). The short and strong limbs end in four-pointed hands and five-pointed feet, which are equipped with claws. As with all Goldmullen, the hands have a digging function and have particularly strong claws. That of the central ray is the largest with a length of 10.3 to 10.5 mm and a base width of 4 mm. The claws on the first and second fingers reach lengths of 4.5 to 7.0 mm, the fourth finger has a clearly developed, 1.5 mm long claw. On the side of the inner edge of the hand there is a wide pad below the first finger, which noticeably widens the forefoot. The feature also occurs in Van Zyl's gold mole ( Cryptochloris zyli ), but is missing in the other gold mole. The hind foot lengths are 10.3 and 10.5 mm, respectively.
Skull and dentition features
The skull lengths are given as 21.3 and 22.0 mm and the skull widths as 15.5 and 16.2 mm. This makes the skull appear short and wide, the greatest width being 70 to 76% of the greatest length. The rostrum is also remarkably wide, the palate width is 7.8 mm, which corresponds to about 35 to 37% of the greatest skull length. A typical feature can be considered the head of the hammer in the middle ear , which is enlarged. In contrast to the closely related Van Zyls Goldmull, the enlargement is largely the result of an inflation and not a club-like elongation. But it leads to the fact that a small bony elevation is visible on the outside of the temporal fossa , in which the head of the hammer lies. The dentition consists of 40 teeth with the following dental formula together: . The molars are equipped with a three-humped ( tricuspid ) chewing surface pattern, the rear molar is mostly of a small shape, but has a similar structure. There is no strong talonid on the lower molars. The length of the upper row of teeth from the front incisor to the last molar is about 9 mm.
distribution
De Winton's gold mole is endemic to southwestern Africa . There it is only known from the type locality near Port Nolloth on the coast of Namaqualand in the South African province of North Cape , the extent of the distribution area is assumed to be 8 km². The region lies in the south-western dry zone of Africa. The species' habitat includes coastal dunes and adjacent sandy areas in the Strandveld Succulent Karoo . It is extremely rare and has only been recorded for three individuals so far, but there is the possibility that observations are seldom made due to the shy nature of the animals and, similar to other gold molluscs in Namaqualand, the population density is underestimated. The desert gold mole also appears sympathetically in the region .
Way of life
Almost nothing is known about the way of life of De Winton's Goldmull. According to individual reports, the animals dig shallow passages and tunnels. These extend over a length of 50 to 60 m and also lead through the roots of bushes, where a larger amount of food is likely available in the form of insects , their larvae and pupae . African blind skinks , legless representatives of the skinks , may also belong to the prey of De Winton's gold mole rat.
Systematics
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Internal systematics of the gold mole according to Asher et al. 2010
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De Winton's gold mole is a species from the genus Cryptochloris , which also includes Van Zyl's gold mole ( Cryptochloris zyli ). The genus, in turn, forms part of the golden mole family (Chrysochloridae). These include smaller, ground grave mammals from the superiority of the Afrotheria shows that endemic in Africa occur. Their main distribution is in the southern part of the continent, a few species also inhabit the eastern or central part. Due to their subterranean way of life, the golden mole can be regarded as habitat specialists , which means that the individual species, with a few exceptions, have a narrowly defined habitat. However, two ecological groups can be distinguished. One group consists of residents to dry partly semi-desert-like landscapes such as the Grant's golden mole ( Eremitalpa ) which chrysochloris ( Chrysochloris ) or the representatives of cryptochloris . The second group includes forms of open grass and savanna landscapes as well as forests, including the copper gold mole ( Amblysomus ), Arends' gold mole ( Carpitalpa arendsi ) or the representatives of the genera Neamblysomus and Chlorotalpa . The internal structure of the gold mole is largely under discussion. On the basis of the construction of the hammer in the middle ear , two or three subfamilies are often distinguished: the Amblysominae with a normally built malleus, the Chrysochlorinae with a greatly elongated head of the malleus and the Eremitalpinae with a spherically inflated head of the malleus. According to other researchers, the latter two form only a single subfamily, the Chrysochlorinae. This subdivision of the gold mole, based on differences in skeletal structure, can not yet be fully understood with the help of molecular genetic results. However, with regard to Cryptochloris, both the skeletal anatomical and the genetic data showed a closer relationship with the Cape Goldmulls. The representatives of both genera have a club-like elongated head of the malleus, which in Cryptochloris is not quite as distinct and extremely elongated as in Chrysochloris . However, the former genus could also be a synonym for the latter, a view that was already held in the 1950s and 1960s and was repeated in 2018, supported by more recent studies.
De Winton's gold mole was first described scientifically in 1907 by Robert Broom under the name Chrysochloris wintoni , he referred the species to the Cape gold mole. As a basis, Broom had a fully grown female individual who was 8.6 cm in length (since the animal was soaked in alcohol , he estimated the actual body length to be 9.2 cm). This came from Port Nolloth in Namaqualand , which is considered a type region. Ten years earlier, Broom had examined two specimens from Port Nolloth and assigned them to the widespread Cape golden mole rat ( Chrysochloris asiatica ), but without having inspected the species more closely beforehand. Later doubts arose and he suspected that the animals were representatives of a new species, which was then confirmed with the description of the type specimen of De Winton's gold mole rat; the animal is now in the South African Museum . The species name refers to the British zoologist William Edward de Winton (1856–1922), who had made an outstanding contribution to the study of African mammals. The current genus name Cryptochloris comes from Guy Chester Shortridge and Donald Carter in 1938. In their publication they placed De Winton's gold mole alongside Van Zyl's gold mole ( Cryptochloris zyli ), which they introduced at the same time and established as a type of their new genus . In the 1950s, Van Zyl's gold mole was designated as a subspecies of De Winton's gold mole, a view confirmed by Alberto Mario Simonetta in 1968. Just a few years later, in 1971, however, Jurgens AJ Meester explained that De Wintons and Van Zyls Goldmull differ not only in the color of their fur, but also in the shape of the hammer . In the former species this has an inflated head, whereas in the latter it is elongated like a club. Thus, both forms are not considered con-specific .
Threat and protection
The IUCN lists De Winton's golden mole in the category "threatened with extinction" ( critically endangered ) with the addition "possibly extinct" ( possible extinct ). The main threat to the existing population is the change in habitat as a result of diamond mining in the coastal sand in the region and infrastructural measures such as the expansion of the port of Port Nolloth. The species is very rarely observed; according to the IUCN, there has been no sighting for more than 50 years. According to the Smithsonian Institution , a specimen is said to have been collected in 1969 from Garies about 181 km southeast of the type locality, which however turned out to be confusion with the desert gold mole. On the other hand, some museum specimens of De Winton's gold mole are misidentified as desert gold mole. The species is not present in any protected area. Research is needed into the actual distribution of De Winton's gold mole, the extent of the threats and all aspects of his way of life.
literature
- Gary N. Bronner: Cryptochloris wintoni De Winton's golden mole. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London, 2013, pp. 250-251
- Gary N. Bronner and Nigel C. Bennett: Cryptochloris wintoni (Broom, 1907). In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 5-6
- William A. Taylor, Samantha Mynhardt and Sarita Maree: Chrysochloridae (Golden moles). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, pp. 180–203 (p. 202) ISBN 978-84-16728-08-4
Individual evidence
- ^ Robert Broom: Some new and some rare Golden moles. Annals of the Transvaal Museum 20, 1946, pp. 329-335
- ^ A b c d e Gary N. Bronner: Cryptochloris wintoni De Winton's golden mole. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London, 2013, pp. 250-251
- ^ A b c d e f Gary N. Bronner and Nigel C. Bennett: Cryptochloris wintoni (Broom, 1907). In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 5-6
- ^ A b c William A. Taylor, Samantha Mynhardt and Sarita Maree: Chrysochloridae (Golden moles). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, pp. 180–203 (p. 202) ISBN 978-84-16728-08-4
- ^ A b Robert Broom: On some new species of Chrysochloris. The Annals and magazine of natural history 7 (19), 1907, pp. 262–268 ( [1] )
- ^ A b c Gary N. Bronner: Cryptochloris wintoni. The IUCN Red List of Threatened Species 2015. e.T5748A21287143 ( [2] ); last accessed on March 5, 2016
- ^ A b Robert J Asher, Sarita Maree, Gary Bronner, Nigel C Bennett, Paulette Bloomer, Paul Czechowski, Matthias Meyer and Michael Hofreiter: A phylogenetic estimate for golden moles (Mammalia, Afrotheria, Chrysochloridae). MC Evolutionary Biology 10, 2010, p. 69 doi : 10.1186 / 1471-2148-10-69
- ^ A b c Alberto M. Simonetta: A new golden mole from Somalia with an appendix on the taxonomy of the family Chrysochloridae (Mammalia, Insectivora). Monitore Zoologico Italiano NS Supplement 2, 1968, pp. 27-55
- ^ Gary N. Bronner: Family Chrysochloridae Golden-moles. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London, 2013, pp. 223-225
- ^ F. Petter: Remarques sur la systematique des Chrysochlorides. Mammalia 45 (1), 1981, pp. 49-53
- ^ Gary Bronner: An imminent updated (2017) taxonomy for golden moles. Afrotherian Conservation 14, 2018, pp. 57–59
- ^ Robert Broom: A contribution to the knowledge of the cape golden moles. Transactions of the South African Philosophical Society 18, 1907, pp. 283-311 ( [3] )
- ↑ Guy Chester Shortridge and Donald Carter: A new genus and new species and subspecies of mammals from Little Namaqualand and the North-West Cape Province; and a new subspecies of Gerbillus paeba from the Eastern Cape Province. Annals of the South African Museum 32, 1938, pp. 281–291 ( [4] )
- ^ Jurgens AJ Meester: Family Chrysochloridae. In: Jurgens AJ Meester and Henry W. Setzer (eds.): The Mammals of Africa: An Identification Manual. Smithsonian Institution Press, Washington, DC, USA., 1971, pp. 1-7
- ^ Smithsonian Institution Collections Search Center
Web links
- Cryptochloris wintoni inthe IUCN Red List of Endangered Species 2015.4. Posted by: Gary Bronner, 2014. Retrieved April 23, 2016.
- Photo of a museum specimen
