Giant gold mole

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Giant gold mole
Giant gold mole (Chrysospalax trevelyani), specimen in the Natural History Museum in London

Giant gold mole ( Chrysospalax trevelyani ), specimen in the Natural History Museum in London

Systematics
Subclass : Higher mammals (Eutheria)
Superordinate : Afrotheria
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Gold mole (Chrysochloridae)
Genre : Giant gold mole
Scientific name
Chrysospalax
Gill , 1883

The giant gold mulle ( Chrysospalax ) are a genus of mammals from the family of the gold mole (Chrysochloridae). The genus includes two species that represent the largest members of the family. The animals live in southern and eastern South Africawhere they inhabit mountain and coastal forest landscapes and open grasslands. They are bound to soft, partly sandy soils. Similar to the other gold mullers, the giant gold mole also have a spindle-shaped body, which lacks externally visible ears and a tail. The front feet have strong digging claws, but they appear relatively slender. The fur of the animals is rough. The Giant Gold Mulle are adapted to an underground way of life because of these body features, but they only dig short tunnels and spend more time on the surface than other members of the family. There they go in search of food, which consists mainly of invertebrates . Little information is available about the way of life as a whole. The genus was established in 1883. Both species of the giant gold mulle are endangered.

features

Habitus

Wire-haired gold mole rat ( Chrysospalax villosus )

The giant gold mulle represent the largest and heaviest representatives of the gold mole . They reach a head-torso length of 12.7 to 23.5 cm. The weight is between 127 and 500 g. Of the two known species is Riesengoldmull ( Chrysospalax trevelyani ) the larger the wire-haired-Goldmull ( Chrysospalax villosus ) smaller. Like all gold moles , they are physically similar to moles , but they are not related to them. Like these, they show special adaptations to a digging way of life, which is expressed, among other things, in the spindle-shaped body with ears and tail that are not externally visible. In addition, the eyes are hidden under the fur and there is a leather-like padding on the nose that is used for digging. The strong limbs appear characteristic, ending in four rays at the front and five at the back. Especially on the forefoot, the claws are transformed into large grave claws; those of the central ray are the longest. Overall, however, the claws show a slim shape. The fur is coarser than that of the other species, it is usually reddish brown, yellowish brown or dark brown in color.

Skull and dentition features

According to their body size, the gold mole also have the largest skull in the family. The greatest length is between 33.4 and 43.2 mm, the greatest width, which is reached in the area of ​​the brain skull, between 19.6 and 27.4 mm. Overall, the skull appears relatively long and narrow with a greatest width, which reaches between 60 and 65% of the greatest length. The rostrum, on the other hand, is rather broad, the palate width corresponds to 30 to 35% of the largest skull length. The zygomatic arches are fully developed. A striking feature are the large bone plates pointing upwards and backwards from the posterior zygomatic arch attachments. They cover the side of the skull like a cap and reach up to the lambda seam . A strong crest is formed as a muscle attachment point on the vertex . Both structures, the bony plates and the crest, are more clearly formed in the giant gold mole than in the wire-haired gold mole. In the middle ear , the head of the hammer is greatly inflated. The malleus has a weight of 146 to 151 mg, which is the largest value within the gold mulle. Due to this enormous enlargement of the malleus head, a bony bladder with a diameter of up to 7 mm appears on the outside of the temporal fossa , in which the hammer is located. The dentition consists of 40 teeth, the dental formula is as follows: . The molars are characterized by three small cusps on the chewing surface ( tricuspid ), the rear molar is significantly smaller than the anterior, but is basically similar to them. A clear trigonid is formed on the lower molars (a deep protrusion of the chewing surface, into which one of the main cusps of the upper molars grips when the dentition closes), such a trigonid also occurs on the lower premolars , which the giant gold mole, for example, from the cape gold mole ( Chrysochloris ) differs. The foremost premolar has a sectorial design and therefore has only two small cusps on the chewing surface. The entire upper row of teeth from the canine to the last molar measures between 6.4 and 10.2 mm.

distribution

The giant gold mole is endemic to southern and southeastern Africa . The giant gold mole inhabits a strip along the south coast of the South African province of Eastern Cape , the wire-haired gold mole is distributed with several subspecies over a relatively large area in eastern South Africa that extends over several provinces. However, both species are only documented in a very small number of locations, so that their actual occurrence remains clearly limited locally. The animals prefer soft, sometimes sandy soils. The giant gold mole can be found predominantly in the original forests of the coastal and mountainous regions, the wire-haired gold mole in densely overgrown, moderately humid grasslands of the high elevations. In contrast to its larger relative, the latter also penetrates into landscapes that are dominated by humans.

Way of life

The way of life of the giant gold mole has been little researched. The animals are predominantly nocturnal and may be less solitary than other members of the family. The long and narrow grave claws do not allow extensive digging activities. The animals therefore only create short tunnels, the entrances of which are connected above ground by a network of paths. Overall, they spend more time on the earth's surface than other members of the gold mole. The food, which mainly consists of invertebrates such as earthworms and insects , is also largely sought above ground. When looking for food, the animals keep their heads close to the ground and dig in the ground with their leathery nasal pads. The enormously enlarged hammer in the middle ear , with which they can perceive seismic vibrations emanating from the prey, may help them to find food . The large malleus also enables better perception in the low frequency range of a few hundred Hertz . Hardly any data are available on reproduction. It is possible that a litter consists of two cubs, in the only birth of a giant gold mole observed so far, only one newborn was born. Postnatal development was relatively slow.

Systematics

Internal systematics of the gold mole according to Asher et al. 2010
 Chrysochloridae  




 Eremitalpa


   

 Huetia


   

 Cryptochloris


   

 Chrysochloris





  Chrysospalax  

 Chrysospalax trevelyani


   

 Chrysospalax villosus




   

 Calcochloris



   

 Chlorotalpa


   


 Carpitalpa


   

 Neamblysomus



   

 Amblysomus



Template: Klade / Maintenance / 3

Template: Klade / Maintenance / Style

The giant gold mulle form a genus within the family of the gold mulle (Chrysochloridae) and the superordinate order of Afrotheria . The family is made up of smaller, soil-digging mammals whose distribution is endemic to Africa . Most species occur in the southern part of the continent, but only a few are found in the eastern or central part. The tenreks (Tenrecidae), which are also common in Africa, are the closest relatives of the golden mole . both together form the order of the Afrosoricida . According to molecular genetic studies, the golden mole and tenreks separated in the transition from the Upper Cretaceous to the Paleocene around 65 million years ago, during the Oligocene around 28.5 million years ago the golden mole began to diversify more strongly.

Theodore Nicholas Gill (1837-1914)

Due to their subterranean way of life, the golden mole can be regarded as habitat specialists , the occurrence of numerous species is therefore clearly limited locally. Two ecological groups can be distinguished within the family. A is from species with an adaptation to dry to some semi-desert formed regions, such as the Grant's golden mole ( Eremitalpa ) or chrysochloris ( Chrysochloris ). The second consists of inhabitants of open grass and savannah landscapes as well as forests, for example the copper gold mulle ( Amblysomus ), Arends' gold mole ( Carpitalpa ), the representatives of Neamblysomus or the giant gold mole . There is still no agreement on the internal structure of the family. From an anatomical point of view, the design of the hammer in the middle ear advocates a division into two or three subfamilies: 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. Some scientists also combine the latter two into a subfamily, the Chrysochlorinae. Molecular genetic studies cannot fully confirm this subdivision of the gold mole, which is based on differences in skeletal anatomy. According to these, the Giant Gold Mulle are relatively basal in a group consisting of the genera Calcochloris , Eremitalpa , Chrysochloris , Cryptochloris and others, which, with the exception of Calcochloris, would generally correspond to the "Chrysochlorinae". From an anatomical point of view, the strongly inflated head of the hammer advocates a closer relationship between Chrysospalax and Eremitalpa (with which it then forms the Eremitalpinae).

There are two types:

The generic name Chrysospalax , which is valid today , was scientifically introduced in 1883 by Theodore Gill . He assigned the two known representatives to his new genus. To distinguish it from the genera of the golden mole ( Chrysochloris and Amblysomus ) already defined at that time , Gill referred to the 40 teeth that are formed in the dentition and to the strong plates behind the zygomatic arches. Independently of Gill, Edward Drinker Cope created the genus Bematiscus nine years later , in which he also placed the giant and wire-haired gold mole rat. He also founded his new genus with the formation of 40 teeth and, unlike Gill, with the distinctive talonid on the lower jaw teeth. In the following period, the giant gold mole was mostly considered to belong to Chrysospalax , while the wire-haired gold mole was incorporated into Bematiscus by the majority of researchers . However, there are no defining differences between the two genera, so that Bematiscus has been synonymous with Chrysospalax since the 1950s . The distinction between the two species is usually based on size, morphological features, such as coat color, and the different habitat preferences .

Tribal history

Fossil remains of gold mole are very rare. Several mandibular fragments are available from the important South African cave site Swartkrans near Johannesburg . The finds, which come from different layers, are between 1.5 and 2.8 million years old and thus belong to the Old Pleistocene . Due to the size of the lower jaws and the current distribution, they are usually associated with the wire-haired gold mole rat. Other finds are known from the nearby Kromdraai site, which are of a similar age. From the Wonderwerk cave south of Kuruman in the South African province of North Cape , remains of giant gold mole were also reported without assigning them to a specific species. The deposits can currently only be dated generally to the Pleistocene , and the site is far from the current range of the genus.

Threat and protection

The existence of the Riesengoldmulles is of the IUCN due to forest and habitat destruction due to the expansion of human settlements and the tourist development of the region as ( "high risk" endangered ) classified. The species also does not tolerate moderate anthropogenic influences on the landscape. The individual populations of the wire-haired golden mole also suffer from the destruction of their habitat. Extensive mining as well as agriculture and grazing are responsible for this. The IUCN leads the way in the "at risk" ( vulnerable ), it is extremely rare. Both the giant and the wire-haired gold mole are present in nature reserves.

literature

  • Gary N. Bronner and Nigel C. Bennett: Genus Chrysospalax Gill, 1883. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 3-5
  • Gary N. Bronner: Genus Chrysospalax 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. 246-250
  • Ronald M. Nowak: Walker's Mammals of the World . The Johns Hopkins University Press, Baltimore 1999, ISBN 0-8018-5789-9
  • 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 ISBN 978-84-16728-08-4
  • Don E. Wilson and DeeAnn M. Reeder (Eds.): Mammal Species of the World . 3rd edition. The Johns Hopkins University Press, Baltimore 2005, ISBN 0-8018-8221-4

Individual evidence

  1. ^ A b c d e f Gary N. Bronner and Nigel C. Bennett: Genus Chrysospalax Gill, 1883. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 3-5
  2. ↑ a b c d e f Gary N. Bronner: Genus Chrysospalax 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. 246-250
  3. ^ A b Matthew J. Mason, Sarah J. Lucas, Erica R. Wise, Robin S. Stein and Melinda J. Duer: Ossicular density in golden moles (Chrysochloridae). Journal of Comparative Physiology A 192, 2006, pp. 1349-1357
  4. ↑ a b c 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
  5. ^ Matthew J. Mason: Bone conduction and seismic sensitivity in golden moles (Chrysochloridae). Journal of Zoology 260, 2003, pp. 405-413
  6. ^ Gary N. Bronner: Notes on the early post-natal development of a giant golden mole (Günther, 1875) born in captivity (Mammalia: Insectivora; Chrysochloridae). Koedoe 35 (2), 1992, pp. 57-58
  7. Jump up ↑ Robert W. Meredith, Jan E. Janečka, John Gatesy, Oliver A. Ryder, Colleen A. Fisher, Emma C. Teeling, Alisha Goodbla, Eduardo Eizirik, Taiz LL Simão, Tanja Stadler, Daniel L. Rabosky, Rodney L. Honeycutt, John J. Flynn, Colleen M. Ingram, Cynthia Steiner, Tiffani L. Williams, Terence J. Robinson, Angela Burk-Herrick, Michael Westerman, Nadia A. Ayoub, Mark S. Springer, and William J. Murphy: Impacts of the Cretaceous Terrestrial Revolution and KPg Extinction on Mammal Diversification. Science 334, 2011, pp. 521-524
  8. ↑ C. Gilbert, PC O'Brien, G. Bronner, F. Yang, A. Hassanin, MA Ferguson-Smith and TJ Robinson: Chromosome painting and molecular dating indicate a low rate of chromosomal evolution in golden moles (Mammalia, Chrysochloridae) . Chromosome Research 14, 2006, pp. 793-803
  9. ^ Gary N. Bronner: Order Afrosoricida Tenrecs, Otter-Shrews, 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. 214-215
  10. ^ A b 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
  11. ^ 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
  12. ^ 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 ISBN 978-84-16728-08-4
  13. ^ Theodore Gill: Insectivora. In: John Sterling Kingsley (ed.): The standard natural history. Volume 5: Natural history of mammals. Boston, 1883, pp. 134–158 (p. 137) ( [1] )
  14. ^ ED Cope: On the Habits and Affinities of the New Australian Mammal, Notoryctes typhlops. The American Naturalist 26 (302), 1892, pp. 121-128
  15. ^ Diana M. Avery: An assessment of the Lower Pleistocene micromammalian fauna from Swartkrans Members 1-3, Gauteng, South Africa. Geobios 31 (3), 1998, pp. 393-414
  16. ^ Diana M. Avery: The Plio-Pleistocene vegetation and climate of Sterkfontein and Swartkrans, South Africa, based on micromammals. Journal of Human Evolution 41, 2001, pp. 113-132
  17. ^ Diana M. Avery, Dominic J. Stratford and Frank Sénégas: Micromammals and the formation of the Name Chamber at Sterkfontein, South Africa. Geobios 43, 2010, pp. 379-387
  18. ↑ TN Pocock: Plio-Pleistocene fossil mammalian microfauna of Southern Africa - a preliminary report including description of two new fossil muroid genera (Mammalia: Rodentia). Palaeontologia Africana 26, 1987, pp. 69-91
  19. ↑ DM Avery: Pleistocene micromammals from Wonderwerk Cave, South Africa: practical issues. Journal of Archaeological Science 34, 2007, pp. 613-625
  20. ↑ Robert J Asher: Tenrecoidea. In: Lars Werdelin and William Joseph Sanders (eds.): Cenozoic Mammals of Africa. University of California Press, Berkeley, London, New York, 2010, pp. 99-106
  21. ^ Gary N. Bronner: Chrysospalax Trevelyani. The IUCN Red List of Threatened Species 2015. e.T4828A21289898 ( [2] ); last accessed on February 20, 2016
  22. ^ Gary N. Bronner: Chrysospalax villosus. The IUCN Red List of Threatened Species 2015. e.T4829A21290416 ( [3] ); last accessed on February 20, 2016

Web links

Commons : Giant Gold Mulle ( Chrysospalax )  - Collection of images, videos and audio files