Huetia

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Huetia
Congo gold mole (Huetia leucorhina) (drawing from the first description by Joseph Huet, 1885)

Congo gold mole ( Huetia leucorhina ) (drawing from the first description by Joseph Huet, 1885)

Systematics
Subclass : Higher mammals (Eutheria)
Superordinate : Afrotheria
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Gold mole (Chrysochloridae)
Genre : Huetia
Scientific name
Huetia
Forcart , 1942

Huetia is a genus of mammals fromthe golden mole family (Chrysochloridae). It comprisestwo specieswith the Congo gold mole and the Somalia gold mole . The distribution areas of the two representatives are in the central and eastern parts of Africa and consist on the one hand of tropical rainforests and on the other hand of open scrubland. The animals are adapted to a burrowing way of life with a spindle-shaped body, covered ears, a missing tail and strong forelimbs. Information on the further way of life is not available, as is the degree of endangerment of the population. The name Huetia was introduced in 1942, the taxon was mainly used in the second half of the 20th century as a sub-unit of various other groups of the golden mole. Only molecular genetic studies from 2010 led to recognition as an independent genus.

features

Habitus

The genus Huetia represents smaller representatives of the golden mole. More detailed information is only available on the Congo gold mole ( Huetia leucorrhina ), which has a head-trunk length of 6.3 to 12.5 cm. As with all gold moles , the body is reminiscent of that of the moles due to the burrowing way of life , to which, however, there are no closer relationships. The body is shaped like a spindle, ears are not externally visible, and the eyes and tail remain hidden under the fur. A leather-like padding is formed on the nose that is used when digging. The limbs are short and strong. There are four rays on the hands and five on the feet, each with claws. The claws of the forefoot have been transformed into digging tools, but have a comparatively slim shape. As a typical feature of burrowing animals, the claw of the central ray (III) is most strongly developed. The back fur is darker in color than the peritoneum.

Skull and dentition features

The skull has a length of 19.5 to 23.1 mm and a width of 16.6 to 20.4 mm wide. Overall, it looks rather stocky, the widest point is reached on the skull. The greatest width is around 70% of the greatest length. The zygomatic arch is fully developed, as is the case with all gold molluscs, but it lacks the wide plates in the rear area, as found in the giant gold mullets ( Chrysospalax ). In contrast to some other representatives of the gold mole, such as the desert gold mole ( Eremitalpa ) or the giant gold mole, there are hardly any specializations in the middle ear . The hammer is not enlarged. Its weight is less than 1 mg. The dentition consists of 40 teeth along the dental formula is accordingly as follows: . Thus, the dentition has three molars both above and below , which is to be regarded as more originally for the gold mulle. Three cusps ( tricuspid ) rise on each of the chewing surfaces of the molars . The lower molars lack a well-developed talonid (a deep protrusion of the chewing surface, into which one of the main cusps of the upper molars engages when the bite is closed). The anterior premolar is molarized and thus resembles the molars.

distribution

The two species of the genus Huetia are endemic to Africa . They occur in two clearly separated areas of distribution. The Congo gold mole lives in the central part of the continent, where it has been found in several, non-contiguous sites in the Congo Basin and adjacent areas. It inhabits tropical rainforests and transitional landscapes to the adjoining savannas . The only evidence of the Somalia gold mole to date comes from north-eastern Africa. The find area in central Somalia consists mainly of bush landscapes.

Way of life

Little information is available about the way of life of the two species of the genus Huetia . It is probably about soil-digging animals like the other gold molluscs.

Systematics

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




 Eremitalpa


   

 Huetia


   

 Cryptochloris


   

 Chrysochloris





   

 Chrysospalax



   

 Calcochloris



   

 Chlorotalpa 


   


 Carpitalpa


   

 Neamblysomus



   

 Amblysomus



Template: Klade / Maintenance / 3

Template: Klade / Maintenance / Style

Huetia is a genus within the family of the golden mole (Chrysochloridae), which summarizes smaller, soil-digging mammals from the parentage of the Afrotheria . The members of the family live endemically in Africa and, with a few exceptions, according to Huetia , their main distribution is found in the southern continental area. The closest relatives are provided by the Tenreks (Tenrecidae), both families together form the Afrosoricida . After molecular genetic investigations, the gold mole and the tenreks were separated from a common lineage in the transition from the Upper Cretaceous to the Paleocene around 65 million years ago. Greater diversification of the gold mole began in the course of the Oligocene about 28.5 million years ago.

The predominantly subterranean way of life of the gold mole has the consequence that the individual representatives represent habitat specialists , the respective occurrence of a species thus has narrow boundaries. Only in a few exceptions are members of the family more common. Two ecological groups can be distinguished within the family. The first group consists of residents of dry to some semi-desert landscapes, this includes the Grant's golden mole ( Eremitalpa ) or chrysochloris ( Chrysochloris ). The second group includes forms with adaptation to open grass and savannah landscapes as well as forests, for example the copper gold mole ( Amblyomus ), the representatives of the genus Neamblysomus , the giant gold mole ( Chrysospalax ) or the representatives of the genus Huetia . The internal structure of the family has not yet been satisfactorily clarified. Usually two or three subfamilies are distinguished based on the construction 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. Other authors, however, see the latter two as a single subfamily, the Chrysochlorinae. This subdivision of the gold mole, which is based on skeletal anatomy, is contrasted with molecular genetic studies, which reveal somewhat different relationships. According to them, Huetia forms a closer relationship with Cryptochloris and Chrysochloris , which are assigned to the Chrysochlorinae due to their elongated malleus. The non-enlarged hammer of the middle ear in Huetia , on the other hand, has so far advocated integration into the amblysominae. A preliminary study from 2018 supports a position of Huetia in a separate subfamily, the Huetinae , based on the genetic data and the anatomical differences .

Two types are distinguished within the genus:

The genus Huetia was introduced by Lothar Forcart in 1942 . He had established it exclusively for the Congo gold mole as a subgenus of Chrysochloris . Forcart assessed the lack of a vesicular enlargement of the posterior part of the temporal fossa as a distinguishing characteristic to Chrysochloris , which in the Cape Goldmulls arises from the extension of the head of the malleus. Forcart named the then sub-genus in honor of Joseph Huet , who in turn introduced the Congo gold mole in 1885.

In the further course the genus Huetia was rarely used as a taxonomic unit. In the 1960s to 1980s in particular, the Congo gold mole was considered to be a representative of the copper gold mole due to the normally built hammer of the middle ear and a member of the genus Chlorotalpa due to the presence of the upper third molar . During the same period, Alberto M. Simonetta had once again scientifically described the Somalia gold mole as belonging to the copper gold mole . Morphometric studies of the cranial skeleton in the 1990s, undertaken by Gary N. Bronner , then led to a provisional inclusion of both the Congo and Somali gold mole rat in the genus Calcochloris ; thus a closer relationship to the yellow gold mole rat ( Calcochloris obtusirostris ) was certified for both species . As common features Bronner emphasized the not enlarged head of the hammer and the principally broad skull structure with the likewise quite broad rostrum . The higher number of teeth in the Congo gold mole compared to the yellow gold mole moved Bronner to assign the former to its own sub-genus, which he indicated as Huetia . For the Somalia gold mole, on the other hand, he did not find a conclusive position, which was due to the limited amount of finds. Therefore Bronner assessed its position with incertae sedis , but noted that the simple construction of the hammer together with the appearance of a third molar support a closer connection with the Congo gold mole. Bronner's structure was later adopted by several other authors.

A molecular genetic analysis by Robert J Asher and research colleagues from 2010, which included the majority of the then known species of the gold mole, but did not take into account the Somalia gold mole, showed that the Congo gold mole did not match the other postulated representatives of the genus Calcochloris Is related. There was also no close relationship with the copper gold mulls or the relatives of Chlorotalpa . Rather, according to the investigations, the Congo gold mole proved to be relatively basal within a group consisting of the desert gold mole, the cape gold mole and the genus Cryptochloris . Asher and colleagues therefore raised Huetia to the level of a genus and assigned it to the Congo gold mole as the only representative. A preliminary study from 2018 saw the Somalia gold mole in turn adopting Bronner's assessment from the 1990s within the genus Huetia , which is also reflected in the eighth volume of the standard work Handbook of the Mammals of the World .

Threat and protection

Both species of the genus Huetia are listed by the IUCN in the category “ data deficient ” due to the limited amount of information available . The distribution area of ​​the Congo gold mole is threatened by massive destruction of the tropical rainforests for agricultural land, infrastructure projects or as a result of illegal construction timber. So far, there is only one specimen of the Somalia gold mole from central Somalia. Investigations into the actual occurrence and way of life are necessary for both species. Some stocks of the Congo gold mole, particularly in the northern part of the Congo Basin, occur in nature reserves.

literature

  • 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. 198) ISBN 978-84-16728-08-4

Individual evidence

  1. ^ A b c d Gary N. Bronner: Calcochloris leucorhinus Congo 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. 234-235
  2. ↑ a b c d e Gary N. Bronner: Calcochloris tytonis Somali 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. 236-237
  3. ↑ Matthew J. Mason, Nigel C. Bennett and Martin Pickford: The middle and inner ears of the Palaeogene golden mole Namachloris: A comparison with extant species. Journal of Morphology 279 (3), 2018, pp. 375-395 doi: 10.1002 / jmor.20779
  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. 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
  6. ↑ 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
  7. ^ 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
  8. ^ 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
  9. ^ 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
  10. ^ Gary N. Bronner and Nigel C. Bennett: Order Afrosoricida. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 1-21
  11. ↑ a b c Gary Bronner: An imminent updated (2017) taxonomy for golden moles. Afrotherian Conservation 14, 2018, pp. 57–59
  12. ^ A b 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. 198) ISBN 978-84-16728-08-4
  13. ^ L. Forcart: Contributions to the knowledge of the insectivore family Chrysochloridae. Revue suisse de zoologie 49, 1942, pp. 1–6 ( [1] )
  14. ↑ Joseph Huet: Espèce nouvelle de Chrysochloridae de la Côte du Golfe de Guinée. Nouvelles archives du Muséum d'histoire naturelle 8, 1885, pp. 1–15 ( [2] )
  15. ^ F. Petter: Remarques sur la systematique des Chrysochlorides. Mammalia 45 (1), 1981, pp. 49-53
  16. ^ Gary N. Bronner: Systematic revision of the Golden mole genera Amblysomus, Chlorotalpa and Calcochloris (Insectivora, Chrysochloromorpha, Chrysochloridae). University of Natal, Pretoria, 1995, pp. 1-346
  17. ↑ Don E. Wilson, DeeAnn M. Reeder (Ed.): Mammal Species of the World . 3rd edition. The Johns Hopkins University Press, Baltimore 2005, ISBN 0-8018-8221-4 ( [3] )
  18. ^ S. Maree: Huetia leucorhina. The IUCN Red List of Threatened Species 2015. e.T40597A21288887 ( [4] ); last accessed on January 17, 2016
  19. ^ S. Maree: Calcochloris tytonis. The IUCN Red List of Threatened Species 2015. e.T4767A21285700. ( [5] ); last accessed on January 26, 2016

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