Tenrek-like

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Tenrek-like
Great tenrek (Tenrec ecaudatus)

Great tenrek ( Tenrec ecaudatus )

Systematics
without rank: Synapsids (Synapsida)
Class : Mammals (mammalia)
Subclass : Higher mammals (Eutheria)
Superordinate : Afrotheria
without rank: Afroinsectiphilia
Order : Tenrek-like
Scientific name
Afrosoricida
Stanhope , Waddell , Madsen , de Jong , Hedges , Cleven , Kao & Springer , 1998

The Tenrekartigen (Afrosoricida) are a recently established order of mammals (Mammalia) based on molecular genetic studies . They summarize the tenreks , otter shrews and the golden mole , three families with around 55 species living in Africa and Madagascar . Morphologically , the Tenre-kitties share so many similarities with the insectivores "in the narrower sense" (scientifically Eulipotyphla), the taxon of hedgehogs , shrews , moles and others, that they used to be in a common order, insectivores "in the broader sense" (scientifically Lipotyphla) were asked. The molecular genetic findings suggest, however, that tenreks and insectivores are not related to each other, but merely developed convergently .

features

Physique and limbs

Great otter shrew ( Potamogale velox )
Giant gold mole ( Chrysospalax trevelyani )

The tenre cardigans have occupied various ecological niches and are accordingly a diverse group. The golden mole (Chrysochloridae) are - similar to the moles - adapted to a way of life that digs underground; within the Tenreks (Tenrecidae) there are shrew-like representatives (the Reistenreks and the Erdtenreks ) and hedgehog-like animals (the Hedgehog Trees ). In addition, with the otter shrews (Potamogalidae) there are also water-dwelling species that appear externally similar to otter. The head-torso lengths vary between 4 and 40 cm. The tail is of different lengths, from stubby short in the golden mole and the hedgehog trek to twice as long as the rest of the body in some small tinker . The weight is between 3 g and 2.4 kg.

The limbs are relatively short. The forefeet of the gold mole has been transformed into highly specialized digging tools, with the claw of the third finger in particular being extended. The limbs of the tenreks have adapted to the respective way of life and are suitable for digging, climbing or running on the ground. Some aquatic species are webbed. With a few exceptions, the hands and feet each have five rays, fingers and toes always have claws. In all tenre cards, the tibia and fibula are often fused at the lower end.

Head and teeth

The head is conical or elongated, the snout pointed. As with many underground mammals, gold owls lack auricles , whereas those of tenreks are relatively large. The eyes are small in the tenreks and the otter shrews, in the golden mole they are covered with fur and have no function. The zygomatic arch , which is not closed in the tenreks and otter shrews, can be used as a characteristic feature . The gold mullet has a complete arch, which is only formed from the front arch attachment and is therefore to be regarded as secondary.

Just like those of insectivores, the teeth are characterized by pointed cusps and sharp enamel ridges. The tooth formula is . So they have a total of 32 to 40 teeth. In the gold mole, the otter shrew and the small tenreks, the foremost upper and the second lower incisor is always enlarged, the canine is always small. In contrast, the hedgehog tenreks and the rice burrowers have enlarged canine teeth. The molars have a zalambdodomntes occlusal surface pattern, that is, a V-shaped enamel ridge (ectoloph) is formed. In addition, there are three main humps, of which the Paraconus is at the tip of the V-shaped ectoloph. In the tenreks and the golden mole, the metaconus merges with the paraconus, in the otter shrews both are clearly separated from each other. The third hump, the protoconus, is reduced to different degrees in the first two groups, but large in the latter.

Internal anatomy

In terms of their internal anatomy, too, the tenre-kitties are very similar to insectivores. The digestive tract is simply built, the appendix is absent in both groups, and the intestine is short and tubular. A peculiarity of the Tenre-kartigen is that the urogenital system, as in the mammals , ends in a single outlet, the cloaca . A similar arrangement can also be found in some shrews and is therefore not a morphological criterion. In the males of most species of Tenre-kartigen, the testicles lie in the abdominal cavity. This distinguishes them from the insectivores, but possibly represents a primeval mammal characteristic. As with the insectivores, the females have a two-horned uterus ( uterus bicornis ).

distribution and habitat

The Tenre-kartigen occur exclusively in Africa south of the Sahara and on Madagascar . The tenreks have their main distribution on Madagascar, the otter shrews are native to the African mainland on both sides of the equator . The golden mole live mainly in the south of the continent, three species live in central Africa, but they are absent in Madagascar.

The Tenre-kartigen inhabit a number of habitats and can be found in dry desert regions as well as in grasslands and forests. The otter shrews and a representative of the tenreks lead a semi-aquatic way of life and can accordingly be found along rivers and other bodies of water. The altitude distribution ranges from sea level to high mountain areas around 4000 m.

Way of life

General

The tenre cardigans have a diverse way of life, which is also reflected in their physique. The gold mole spend most of their life underground. There are also some burrowing species among the tenreks, although not to the same extent. However, a larger proportion of the tenreks live on the ground or climb trees. With some tenreks, especially from the group of small tenreks, a long prehensile tail is developed for this . The otter shrews and the water tenrek tend to be in the water when foraging for food. Most tenre cardigans use burrows that they dug themselves as shelter. With a few exceptions, the animals live solitary and avoid contact with conspecifics outside of the mating season.

A peculiarity of the Tenre-Kartigen is that their body temperature is more flexible than that of most other mammals and can partly be adapted to the environment. Many species fall into a torpor (state of rigidity), either daily or when the outside temperature is cool and there is little food available.

food

The diet of the Tenre-Kartigen consists of insects and other invertebrates such as earthworms , the aquatic species also eat crustaceans . Small vertebrates, carrion and vegetable matter complement the menu to varying degrees.

Reproduction

Little is known about reproduction, but it varies depending on the species. The litter sizes vary between one and 32 in the case of the Great Tenrek , the latter being the highest value of all mammals. Newborns are born in the protected den of the mother - who is usually solely responsible for raising the young. You are helpless at first, but grow quickly.

Systematics

External and internal systematics

Internal systematics of Afrotheria according to Kuntner et al. 2011
 Afrotheria  
  Paenungulata  

 Sirenia (manatees)


   

 Hyracoidea (hyrax)


   

 Proboscidea ( proboscidea )




  Afroinsectiphilia  

 Tubulidentata (aardvark)


  Afroinsectivora  

 Macroscelidea (elephant)


  Afrosoricida  

 Chrysochloridae (golden mole)


  Tenrecomorpha  

 Potamogalidae (Otter shrews)


   

 Tenrecidae (Tenreks)







Template: Klade / Maintenance / Style

On the basis of molecular genetic studies, the Tenre-Kartigen are assigned to the Afrotheria , an externally heterogeneous group of mammals that originated on the African continent. The relationships to other groups within the Afrotheria have not yet been completely dissolved. In numerous genetic studies the elephants (Macroscelidea) represent the sister group of the Tenre-kitties, together with the aardvark (Tubulidentata) these groups form the taxon of Afroinsectiphilia .

Today, three families can be distinguished within the Tenre cards:

  • Order Afrosoricida Stanhope, Waddell, Madsen, de Jong, Hedges, Cleven, Kao & Springer , 1998 (Tenrekiformes)

The golden mole are partly morphologically divided into two or three subfamilies (Chrysochlorinae and Amblysominae, partly also the Eremitalpinae) due to a different structure of the ear, but genetic data do not fully support this. The tenreks can be divided into three morphologically well-defined subfamilies: the earth tenreks (Geogalinae), the rice treks (Oryzorictinae) and the hedgehog tenreks (Tenrecinae). (For more details see under the systematics of the golden mole and the systematics of the tenreks .) The monophyly of the three families was confirmed by molecular genetic studies, which has disproved previous assumptions based on anatomical comparisons that the otter shrews could be the sister group of all other tenreks or the hedgehog tenreks are closer to them the Goldmullen as related to the other Tenreks. According to genetic studies, the now extinct genus Plesiorycteropus is related to the Tenreks . The representatives of the genus were native to Madagascar until around 1000 years ago, but originally they were assigned a closer relationship to the aardvark or they were part of the independent order Bibymalagasia.

History of research and systematics

Since the establishment of the order of the insectivores (Insectivora) by Thomas Edward Bowdich in 1821, the affiliation of the Tenreks and Goldmulle has been largely beyond doubt. This order has an eventful taxonomic history, and even when some taxa such as giant gliders , shrews and elephants were later outsourced, the relationship was considered certain until the 1990s due to the morphological similarities. The internal systematics of these insectivores in the broader sense was always controversial. For example, the Tenreks were often viewed as close relatives of the slit weevils, the golden mole were considered, among other things, to be closely related to the moles or as a basal group that faced all other insect eaters.

With the introduction of molecular genetic research into zoological systematics, this perspective has changed. In 1997, a research team led by Mark S. Springer first identified the golden mole as outside of insectivores and classified it in a clade of African mammals. In the following year, Michael J. Stanhope and colleagues recognized that the tenreks also belong to this group and that they have one thing in common with the golden mole Form taxon. They also coined the scientific name Afrosoricida, as well as the term Afrotheria for the overarching common group of African animals. Numerous subsequent molecular investigations have confirmed the paraphyly of the insectivores in the broader sense (lipotyphla), so that today there is broad consensus on the division into two groups, the tenre-kittens (Afrosoricida) and the insectivores (Eulipotyphla).

Taxonomy

The scientific term Afrosoricida translates directly into “African shrews”. The term is controversial because it is based on the taxon Afrosorex , which was introduced by Rainer Hutterer in 1986 . In today's system, Afrosorex designates a sub-genus within the white-toothed shrew ( Crocidura ) and includes species such as Fischer's shrew or Mac Arthur's shrew , so it is clearly related to insect- eater . Some scientists therefore prefer other names for the Tenre-kartigen. Tenrecoidea is often used with reference to Samuel Booker McDowell 1958. McDowell had defined the Tenrecoidea as a superfamily including the tenreks (including the otter shrews) and the golden mole. However, the term was first used by George Gaylord Simpson in 1931, who classified the tenreks together with the otter shrews, the slotted weevils and some extinct groups, albeit excluding the golden mole. It is therefore also the opinion that McDowell's redefinition is an unjustified extension of the Simpson taxon. A partially used name is Tenrecomorpha. This comes from Percy M. Butler from 1972, but only refers to the Tenreks and the otter shrews. It is therefore also understood in this clear form in some more recent works. Because of this taxonomic “previous load” of other potential names for the Tenre-kitties, Afrosoricida is widely accepted despite the problematic name reference.

Tribal history

According to the molecular clock, the origins of the Tenre-kartigen date back to the Cretaceous-Tertiary boundary about 68 million years ago. The fossil record of the group is very poor. The oldest known fossils come from southwest Africa and date to the Middle Eocene around 48 to 41 million years ago. Various remains of teeth from the Black Crow site in the restricted diamond area of Namibia are assigned to the genera Diamantochloris and Damarachloris . Both represent early forms of the golden mulle, but differ in terms of body size. Another, less than 1 cm long lower jaw branch represents Nanogale , which belongs to the relationships between tenreks and otter shrews . Comprehensive skeletal finds from the Eocliff , also in the restricted area, which date to the Upper Eocene, are only a little more recent . Here, several representatives are also detected, they include with Namachloris one hand golden moles, with Namagale other hand potamogalinae and with Sperrgale and Arenagale also tenrecs. Accordingly, all three families are already present at this point in time. Other early finds came to light in the Lower Miocene of eastern and southwestern Africa. These include, Protenrec , Parageogale and Erythrozootes , three related to tenrecs forms. Prochrysochloris is also documented, which in turn is closer to the gold mole.

The position of some forms from the transition from the Eocene to the Oligocene of the Fayyum area in northern Egypt is controversial , including Widanelfarasia , Dilambdogale and Jawharia . The found material consists largely of upper and lower jaw remains. What is remarkable about the maxillary teeth is that the posterior molars have a zalambdodontic occlusal surface pattern, but the anterior one has a dilambdodontic pattern . From a phylogenetic point of view, the forms mentioned are possibly at the basis of the development of the Tenre-kartigen.

literature

  • 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. 223-257
  • Nick Garbutt: Mammals of Madagascar. A complete guide. Yale University Press, 2007, pp. 1–304 (pp. 32–56)
  • Matthew Symonds: Phylogeny and life histories of the "Insectivora": controversies and consequences. Biological Reviews 80, 2005, pp. 93-128
  • Don E. Wilson, DeeAnn M. Reeder (Eds.): Mammal Species of the World. 3rd edition. The Johns Hopkins University Press, Baltimore 2005, ISBN 0-8018-8221-4
  • Peter Vogel: Subfamily Potamogalinae Otter Shrew. 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. 216-222

credentials

  1. ↑ a b c d e f g h i j k 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. 223-257
  2. ↑ a b c d e f g h i j k Nick Garbutt: Mammals of Madagascar. A complete guide. Yale University Press, 2007, pp. 1–304 (pp. 32–56)
  3. ^ A b c d Matthew Symonds: Phylogeny and life histories of the "Insectivora": controversies and consequences. Biological Reviews 80, 2005, pp. 93-128 doi: 10.1017 / S1464793104006566
  4. ↑ a b c d e f g h i j k Peter Vogel: Subfamily Potamogalinae Otter Shrew. 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. 216-222
  5. ^ Robert J. Asher and Marcelo R. Sánchez-Villagra: Locking Yourself Out: Diversity Among Dentally Zalambdodont Therian Mammals. Journal of Mammalian Evolution. 12 (1/2), 2005, pp. 265-282
  6. ^ A b Matjaž Kuntner, Laura J. May-Collado and Ingi Agnarsson: Phylogeny and conservation priorities of afrotherian mammals (Afrotheria, Mammalia). Zoologica Scripta 40 (1), 2011, pp. 1-15
  7. ↑ Peter J. Waddell, Hirohisa Kishino and Rissa Ota: A Phylogenetic Foundation for Comparative Mammalian Genomics. Genome Informatics 12, 2001, pp. 141-154
  8. ↑ Robin MD Beck, Olaf RP Bininda-Emonds, Marcel Cardillo, Fu-Guo Robert Liu and Andy Purvis: A higher-level MRP supertree of placental mammals. BMC Evolutionary Biology 6, 2006, p. 93 doi: 10.1186 / 1471-2148-6-93
  9. ↑ a b Kathryn M. Everson, Voahangy Soarimalala, Steven M. Goodman and Link E. Olson: Multiple loci and complete taxonomic sampling resolve the phylogeny and biogeographic history of tenrecs (Mammalia: Tenrecidae) and reveal higher speciation rates in Madagascar's humid forests. Systematic Biology 65 (5), 2016, pp. 890-909 doi: 10.1093 / sysbio / syw034
  10. ^ 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). BMC Evolutionary Biology 10, 2010, p. 69 doi : 10.1186 / 1471-2148-10-69
  11. ↑ Christophe J. Douady, Francois Catzeflis, Diana J. Kao, Mark S. Springer and Michael J. Stanhope: Molecular evidence for the monophyly of tenrecidae (mammalia) and the timing of the colonization of Madagascar by Malagasy Tenrecs. Molecular Phylogenetics and Evolution 22 (3), 2002, pp. 357-363 doi: 10.1006 / mpev.2001.1055
  12. ^ Robert J. Asher: A morphological basis for assessing the phylogeny of the "Tenrecoidea" (Mammalia, Lipotyphla). Cladistics 15, 1999, pp. 231-252
  13. ↑ Michael Buckley: A Molecular Phylogeny ofPlesiorycteropus Reassigns the Extinct Mammalian Order 'Bibymalagasia'. PlosOne 8 (3), 2013, p. E59614 doi: 10.1371 / journal.pone.0059614
  14. ^ Thomas Edward Bowdich: An analysis of the natural classifications of Mammalia for the use of students and travelers. Paris, 1821, pp. 1–115 (pp. 31–33) ( [1] )
  15. ^ William King Gregory: The orders of mammals. Bulletin of the American Museum of Natural History 27, 1910, pp. 1–524 (pp. 464–465)
  16. ↑ Mark S. Springer, Gregory C. Cleven, Ole Madsen, Wilfried W. de Jong, Victor G. Waddell, Heather M. Amrine and Michael J. Stanhope: Endemic African mammals shake the phylogenetic tree. Nature 388, 1997, pp. 61-64
  17. ↑ Michael J. Stanhope, Victor G. Waddell, Ole Madsen, Wilfried de Jong, S. Blair Hedges, Gregory C. Cleven, Diana Kao and Mark S. Springer: Molecular evidence for multiple origins of Insectivora and for a new order of endemic African insectivore mammals. PNAS 95, 1998, pp. 9967-9972 doi: 10.1073 / pnas.95.17.9967
  18. ↑ a b 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
  19. ↑ Maureen A. O'Leary, Jonathan I. Bloch, John J. Flynn, Timothy J. Gaudin, Andres Giallombardo, Norberto P. Giannini, Suzann L. Goldberg, Brian P. Kraatz, Zhe-Xi Luo, Jin Meng, Xijun Ni, Michael J. Novacek, Fernando A. Perini, Zachary S. Randall, Guillermo W. Rougier, Eric J. Sargis, Mary T. Silcox, Nancy B. Simmons, Michelle Spaulding, Paúl M. Velazco, Marcelo Weksler, John R Wible and Andrea L. Cirranello: The Placental Mammal Ancestor and the Post-K-Pg Radiation of Placentals. Science 339 (6120), 2013, pp. 662-667, doi: 10.1126 / science.1229237
  20. ^ Samuel Booker McDowell: The Greater Antillean insectivores. Bulletin of the American Museum of Natural History 115, 1958, pp. 115-213
  21. ↑ George Gaylord Simpson: A new classification of mammals. Bulletin of the American Museum of Natural History 59, 1931, pp. 259-293
  22. ^ Robert J Asher and Kristofer M Helgen: Nomenclature and placental mammal phylogeny. BMC Evolutionary Biology 10, 2010, p. 102 ( [2] )
  23. ^ 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
  24. ↑ Martin Pickford: Chrysochloridae (Mammalia) from the Lutetian (Middle Eocene) of Black Crow, Namibia. Communications of the Geological Survey of Namibia 16, 2015, pp. 105–113
  25. ^ Martin Pickford: Diamantochloris mandible from the Ypresian / Lutetian of Namibia. Communications of the Geological Survey of Namibia 19, 2018, pp. 51–65
  26. ^ Martin Pickford: New Chrysochloridae (Mammalia) from the middle Eocene of Black Crow, Namibia. Communications of the Geological Survey of Namibia 21, 2019, pp. 40–47
  27. ↑ Martin Pickford: Tiny Tenrecomorpha (Mammalia) from the Eocene of Black Crow, Namibia. Communications of the Geological Survey of Namibia 21, 2019, pp. 15-25
  28. ↑ Martin Pickford: Late Eocene Chrysochloridae (Mammalia) from the Sperrgebiet, Namibia. Communications of the Geological Survey of Namibia 16, 2015, pp. 153–193
  29. ↑ Martin Pickford: Late Eocene Potamogalidae and Tenrecidae (Mammalia) from the Sperrgebiet, Namibia. Communications of the Geological Survey of Namibia 16, 2015, pp. 114–152
  30. ^ Robert J. Asher: Recent additions to the fossil record of tenrecs and golden moles. Afrotherian Conservation 15, 2019, pp. 4–13
  31. ↑ Percy M. Butler: Insectivora and Chiroptera. In: VJ Maglio and HBS Cooke (eds.): Evolulion of African Mammals. Harvard University Press, 1978, pp. 56-68
  32. ^ Percy M. Butler: Macroscelidea, Insectivora and Chiroptera from the Miocene of East Africa. Palaeovertebrata 14 (3), 1984, pp. 117-200
  33. ↑ Pierre Mein and Martin Pickford: Insectivora from Arrisdrift, a basal Middle Miocene locality in southern Namibia. Memoir of the Geological Survey of Namibia 19, 2003, pp. 143-146
  34. ^ A b 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
  35. ^ Erik R. Seiffert and Elwyn L. Simons: Widanelfarasia, a diminutive placental from the late Eocene of Egypt. PNAS 97 (6), 2000, pp. 2646-2651
  36. ↑ Erik R. Seiffert, Elwyn L. Simons, Timothy M. Ryan, Thomas M. Bown and Yousry Attia: New remains of Eocene and Oligocene Afrosoricida (Afrotheria) from Egypt, with implications for the origin (s) of afrosoricid zalambdodonty. Journal of Vertebrate Paleontology 27 (4), 2007, pp. 963-972
  37. ^ Erik R. Seiffert: The oldest and youngest records of afrosoricid placentals from the Fayum Depression of northern Egypt. Acta Palaeontologica Polonica 55 (4), 2010, pp. 599-616

Web links

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