Neamblysomus

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Neamblysomus
Systematics
Subclass : Higher mammals (Eutheria)
Superordinate : Afrotheria
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Gold mole (Chrysochloridae)
Genre : Neamblysomus
Scientific name
Neamblysomus
Roberts , 1924

Neamblysomus is a genus of mammals from the golden mole family(Chrysochloridae). The genus includes two species thatare endemic to the Transvaal regionof South Africa . However, their distribution is limited to a few, narrowly defined localities in moderately humid landscapes of montane forests or open scrubland areas. They live solitary and underground. Like the other gold mole, the animals are adapted to life underground with a spindle-shaped body and powerful grave claws on their forefeet. The comparatively graceful physique binds the animals to loose soils. The main diet consists mainly of invertebrates . There is hardly any information about the exact way of life. The genre was established in 1924, but it was only widely accepted in the transition from the 20th to the 21st century. The populations of the two species are classified as critically endangered.

features

Habitus

The representatives of the genus Neamblysomus belong to the smaller gold mole . Their head-torso length ranges from 9.2 to 13.2 cm, their weight varies between 21 and 70 g. Of the two known species, Juliana's golden mole ( Neamblysomus julianae ) is the smaller, Gunnings golden mole ( Neamblysomus gunningi ) is the larger. In their physique, the animals are similar to the moles , but they are not related to them. They show clear adaptations to a way of life that digs underground. The body has a spindle-shaped shape and is characterized by ears and a tail that are not visible from the outside. The eyes are covered with fur, the snout has a leather-like padding that is partially used for digging. The short, soft fur is light to dark brown on the back and often appears lighter on the belly. The limbs are generally strong and short, the hands have four rays and the feet have five rays. The front limbs are transformed into digging tools, each with a large digging claw on the central ray (III). The other fingers show shorter claws. Overall, the physique appears somewhat more graceful than that of the closely related copper gold mulle ( Amblysomus ).

Skull and dentition features

The skull becomes 21.8 to 29 mm long and 14.7 to 18.2 mm wide. It is built relatively narrow, the widest point is on the skull, the width is about 60 to 68% of the greatest length. The palate is also relatively narrow and has a width of around 30% of the greatest length of the skull. The zygomatic arch is fully developed, it does not end in broad plates at the back, as occur, for example, in the giant gold mole ( Chrysospalax ). The middle ear shows hardly any specialization, the hammer is not enlarged as in some representatives of the gold mole, its weight is less than 1 mg. The bit of Neamblysomus consists of a total of 36 teeth teeth with the following dental formula together: . The chewing surfaces of the molars consist of three small cusps ( tricuspid ), in contrast to the closely related gold copper cusps , the lower rear molars lack a well-developed talonid (a deep protrusion of the chewing surface into which one of the main cusps of the upper molars grips when the bite is closed). A rearmost, third molar is also more common than the copper gold mullet, even if it is variable in the individual jaw sections. As a rule, however, it is only a third the size of the anterior molar and has a nail-like shape. The length of the entire upper row of teeth from the canine to the last molar varies between 5.5 and 7.3 mm.

distribution

The two Neamblysomus species are endemic to southern Africa . Their distribution area is limited to only a few sites, which are spread over the South African provinces of Gauteng , Mpumalanga and Limpopo . The animals tend to inhabit medium-humid ( Mesian ) landscapes, with Gunnings Goldmull occurring in the mountain forests of the Drakensberg , Julianas Goldmull, on the other hand, is native to various landscapes of the Bush and Lowfeld. Their distribution areas therefore extend over parts of the Zambezi woodland zone. Due to the somewhat slimmer physique and the less powerful grave claws compared to the copper gold mole, the animals prefer loose soils. Sometimes they occur locally quite frequently, sometimes they also penetrate cultivated areas such as gardens.

Way of life

Little is known about the way of life of these animals. Like all gold mole, they mostly live underground, where they create passages for foraging and resting. If the temperature conditions are unfavorable, they fall into a torpor . The animals should live solitary and live in fixed territories. The diet consists of invertebrates such as insects and earthworms . Similar to the related copper gold mole, the representatives of Neamblysomus are rarely found on the earth's surface. Possibly, due to the normally built, non-inflated hammer in the middle ear, unlike some other gold mole, they can only perceive low-frequency noises and seismic signals to a limited extent . However, the ability to perceive low-frequency sounds is on average slightly better developed in Neamblysomus than in Amblysomus . Reproduction is likely to be seasonal. A litter usually consists of two young animals.

Systematics

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




 Eremitalpa


   

 Huetia


   

 Cryptochloris


   

 Chrysochloris





   

 Chrysospalax



   

 Calcochloris



   

 Chlorotalpa


   


 Carpitalpa


  Neamblysomus  

 Neamblysomus gunningi


   

 Neamblysomus julianae




   

 Amblysomus



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Template: Klade / Maintenance / Style

Neamblysomus is a genus from the family of the golden moles (Chrysochloridae) and the superiority of the Afrotheria . The gold mole represent smaller, soil-digging mammals that are endemic to Africa . With a few exceptions, the main focus of their distribution is in southern Africa. The tenreks (Tenrecidae), which also occur in Africa and with which they together form the order of the Afrosoricida, are considered to be the closest relatives of the golden mole . The origin of this group goes back a long way; 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. Further diversification of the gold mole began in the course of the Oligocene about 28.5 million years ago.

The golden mole are to be regarded as habitat specialists due to their underground way of life . As a result, the habitats of most species are clearly limited locally. However, two ecological groups can be distinguished within the family. One is made up of representatives with an adaptation to dry to some semi-desert formed regions, including for example, the Grant's golden mole ( Eremitalpa ) or chrysochloris ( Chrysochloris ) are to be counted. In the second group are the people open grass and savannah , as well as woods, such as the types of Neamblysomus and amblysomus ( Amblysomus ), but also the chrysospalax ( Chrysospalax ) or Arends' Goldmull ( Carpitalpa ). The internal structure of the family must be viewed as not yet fully clarified. Morphologically, two or three subfamilies can be distinguished based on the structure of the hammer in the middle ear : 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 some scientists, the latter two also form only one subfamily, the Chrysochlorinae. However, this subdivision based on differences in skeletal anatomy cannot yet be fully understood with the aid of molecular genetic data. Accordingly, Carpitalpa and Amblysomus are the closest relatives of Neamblysomus . The separation of Neamblysomus from the closely related copper gold mole took place in the Miocene around 10 million years ago.

Within the genus Neamblysomus , two types are distinguished today:

Austin Roberts

It is possible that the easternmost of the three subpopulations of Julianas Goldmull, which differs in terms of coat color as well as tooth characteristics and genetic data, is an independent species, but more detailed studies are still lacking.

The genus Neamblysomus was first scientifically described by Austin Roberts in 1924 . He named Gunnings Goldmull as a type species. The introduction of the new genus took place due to different tooth characteristics. The rearmost, third molar tooth is seldom developed in the copper gilds , but it occurs frequently in Neamblysomus , albeit variable in its design. The copper gold mole, in turn, has a pronounced talonid on the lower, rear molars, which is absent in Neamblysomus . In general, Roberts confirmed the great similarity of the two genera. In the period that followed, the representatives of the genus Neamblysomus were listed together with those of Chlorotalpa and Calcochloris within the copper gold mulle, but all four genera differ in some anatomical features. In addition to the tooth features, there are also deviations in the expression of the hyoid bone , as well as in the karyotype . This appears to justify a division into several genera, which is why Gary N. Bronner reintroduced the genus Neamblysomus in the mid-1990s. Above all, the chromosome examinations showed that the representatives of Neamblysomus form a clade separated from the copper gold mole . These results were confirmed in later molecular genetic analyzes.

Tribal history

In general, gold mole are rarely featured in the fossil record . Several skull and jaw fragments of a small representative of the family are available from the important South African cave sites of Sterkfontein , Swartkrans and Kromdraai . Due to the formation of ten teeth in the lower jaw, the absence of the talonid on the molars , the relatively small canine and comparatively large first premolars , an assignment to Neamblysomus is favored, possibly representing Julianas Goldmull. Other authors referred the finds to the genus Chlorotalpa , which newer investigations refute. The sites date to the Lower Pleistocene , the absolute dates vary between 1 and 2 million years.

Threat and protection

Due to the small area of distribution of the two Neamblysomus types, and the destruction of their habitats and further fragmentation of the habitats due to intensification of agriculture, forestry and mining both types of the are IUCN as "at high risk" ( endangered listings), individual ones of the degree of danger, local populations can be higher. Both species are present in nature reserves.

literature

  • Gary N. Bronner: Genus Neamblysomus 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. 255-257
  • Gary N. Bronner and Nigel C. Bennett: Genus Neamblysomus Roberts, 1924. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 14-16
  • 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 g Gary N. Bronner and Nigel C. Bennett: Genus Neamblysomus Roberts, 1924. In: John D. Skinner and Christian T. Chimimba (eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 14-16
  2. ↑ a b c d e f Gary N. Bronner: Genus Neamblysomus 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. 255-257
  3. ↑ 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. ^ J. Meester: A new golden mole from the Transvaal (Mammalia: Chrysochloridae). Annals of the Transvaal Museum 28 (4), 1972, pp. 35-46
  5. ^ Matthew J. Mason: Bone conduction and seismic sensitivity in golden moles (Chrysochloridae). Journal of Zoology 260, 2003, pp. 405-413
  6. ↑ 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
  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. ↑ Samantha Mynhardt, Sarita Maree, Illona Pelser, Nigel C. Bennett, Gary N. Bronner, John W. Wilson and Paulette Bloomer: Phylogeography of a Morphologically Cryptic Golden Mole Assemblage from South-Eastern Africa. PlosONE 10 (12), 2015, p. E0144995 doi : 10.1371 / journal.pone.0144995
  13. ^ 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
  14. ^ A b S. Maree: Neamblysomus julianae. The IUCN Red List of Threatened Species 2015. e.T1089A21285354 ( [1] ); last accessed on December 17, 2015
  15. ^ Austin Roberts: Some additions to the list of South African Mammals. Annals of the Transvaal Museum 10 (2), 1924, pp. 59-76
  16. ^ F. Petter: Remarques sur la systematique des Chrysochlorides. Mammalia 45 (1), 1981, pp. 49-53
  17. ^ Gary N. Bronner: Comparative hyoid morphology of nine chrysochlorid species (Mammalia: Chrysochloridae). Annals of the Transvaal Museum 35 (21), 1991, pp. 295-311
  18. ^ Gary N. Bronner: Cytogenetic Properties of Nine Species of Golden Moles (Insectivora: Chrysochloridae). Journal of Mammalogy 76 (3), 1995, pp. 957-971
  19. ^ Gary N. Bronner, M. Hoffmann, PJ Taylor, CT Chimimba, PB Best, CA Matthee and TJ Robinson: A revised systematic checklist of the extant mammals of the southern African subregion. Durban Museum Novitates 28, 2003, pp. 56-95
  20. ↑ 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
  21. ^ 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
  22. ^ 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
  23. ^ 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
  24. ^ S. Maree: Neamblysomus gunningi. The IUCN Red List of Threatened Species 2015. e.T1087A21283546 ( [2] ); last accessed on December 6, 2015

Web links

Commons : Neamblysomus  - collection of images, videos and audio files