Otter shrews

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Otter shrews
Great otter shrew (Potamogale velox)

Great otter shrew ( Potamogale velox )

Systematics
Class : Mammals (mammalia)
Subclass : Higher mammals (Eutheria)
Superordinate : Afrotheria
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Otter shrews
Scientific name
Potamogalidae
Allman , 1865

The otter shrews (Potamogalidae) are a family of mammals consisting of three species in two genera: the large otter shrew and the two species of the small otter shrew , the dwarf and the Ruwenzori otter shrew . All three representatives occur only on the African mainland and inhabit the tropical rainforests on both sides of the equator . The animals prefer landscapes with small, clear bodies of water. They are adapted to aquatic life and swim in search of food at night. They mainly feed on crabs and fish . Generally they live solitary and spend the day in a burrow. The exact way of life of the otter shrews has so far hardly been researched. in their appearance they are adapted to life in water. They have an otter-like shape with a flattened snout with numerous whiskers and a muscular tail. The locomotion in the water is mainly done by snaking movements of the tail, but one species has webbed feet and also uses its legs to paddle.

The closest relatives of the otter shrews are the Tenreks (Tenrecidae), which are endemic to Madagascar . The two groups separated almost 50 million years ago. Sometimes the otter shrews were also viewed as an African branch of the Tenreks; from a molecular genetic point of view, the long splitting period, in addition to some anatomical differences , advocates an independent family status. The otter shrews have so far only rarely been documented in the fossil record , a few finds come from southwestern Africa and are around 40 million years old. The first reports from current representatives of the family date back to the 1860s. They refer to the large otter shrew, the two members of the small otter shrews were only discovered around a hundred years later. As a rule, the otter shrews were regarded as part of the insect eater in their research history . In the transition from the 20th to the 21st century, however, genetic studies revealed a closer relationship to other originally African animals. Of the three species today, one is classified as endangered.

features

Habitus

Otter shrews are small representatives of mammals. They have a head-to-trunk length of 12 to 20 cm for the small otter shrews ( Micropotamogale ) and from 30.5 to 33.7 cm for the large otter shrew ( Potamogale ). The tail is between 9.5 and 29.0 cm long, it reaches between 77 and 84% of the length of the rest of the body. The body weight varies from 32 to 780 g. As the name suggests, the animals have a distant resemblance to otters in their external appearance . Their body is streamlined, the muzzle broad and flattened with a mouth below. The body is covered by a dense undercoat, which is covered by shiny outer hair. The shine is caused by the flattened tips of the hair. The fur is dark brown on the top and whitish on the underside. The pygmy otter shrew ( Micropotamogale lamottei ), whose body appears uniformly dark in color, is an exception . A striking feature is the leathery nasal mirror , which is mostly heart-shaped and divided by a longitudinal furrow. The nostrils on the side above can be closed by small flaps. On the upper lip there is a wreath of stiff vibrissae , further whisker hairs can be found over the eyes and on the lower jaw. The eyes themselves are small, the auricles have an elongated oval shape and protrude from the fur. The tail is strong and long, with the great otter shrew it shows a laterally clearly flattened shape, with the Ruwenzori otter shrew ( Micropotamogale ruwenzorii ) it is only slightly flattened, while it has a round cross section in the dwarf otter shrew. The short and strong limbs each end in five rays. Webbed fingers and toes are only found in the Ruwenzori otter shrew. As is typical for all otter shrews, the second and third rays of the rear foot form a functional unit, so the toes are syndactyl . All fingers and toes have curved claws.

Skull and dentition features

The skull of the otter shrews is generally narrow, the greatest width is reached at the brain skull. When viewed from above, the skull looks drop-shaped with a long rostrum . In side view, the forehead line is almost straight. There is a crest on the parietal bone . The zygomatic arch is not closed. The glenoid pit, the point of attachment of the mandibular joint, is located under the posterior arch attachment on the temporal bone . The nasolacrimal duct (ductus nasolacrimalis) and the lacrimal foramen are absent, which is related to the reduction in the sense of smell. An ossified tympanic bladder is also conspicuous at the base of the skull .

The bit is made up of a total of 40 teeth with the following dental formula together: . A characteristic feature is the enlarged first upper and the second lower incisor . They are reminiscent of canine teeth in their appearance and act as opponents when grabbing prey. The following teeth including the canine and the anterior premolars show a simple structure. There are differences in the size of these teeth between the individual species. Clear variations can be seen in the pygmy otter shrew, while in the great otter shrew all of the teeth in this section have roughly the same dimensions. As a result, the teeth appear differently specialized in the respective species. The upper canine also always has two roots. The molars have a distinctive chewing surface pattern that includes three main cusps: the para-, meta- and protoconus (related to the maxillary teeth). The protoconus is well developed, the metaconus, unlike the tenreks, does not merge so clearly with the paraconus, the latter represents the main cusp of the molars. Here, too, differences between the species are pronounced, such as the separation between the last two cusps in the great otter shrew more conspicuous than with the small otter shrews. A V-shaped shear bar (ectoloph), the tip of which is formed by the paraconus, is also characteristic. The molars can therefore be viewed as largely zalambdodont . The rearmost upper molar shows a marked reduction in size.

Skeletal features

Skeleton of the great otter shrew

The spine of the otter shrews consists of 7 cervical, 16 to 17 thoracic, 5 to 6 lumbar, 5 sacrum and 31 to 34 caudal vertebrae. Examined pups of the pygmy otter shrew have 24 to 25 caudal vertebrae. Strongly developed spinous and transverse processes as well as robust hemal arches appear on the anterior caudal vertebrae . Their size decreases towards the back

A noticeable difference to the tenreks is the absence of the collarbone in the otter shrews. The shoulder blade of the great otter shrew is very long and narrow, but unlike the tenreks it has no pronounced acromion, where parts of the deltoid muscle normally attach. Also in contrast to the tenreks, the humerus has a very elongated shape compared to the bones of the forearm. The large tubercle of the humerus protrudes steeply as a claw-like appendage and is less reminiscent of tenreks than of bats . It blocks against the shoulder blade and prevents arm movements that are too far out. The lower humeral joint (elbow) is very slender, but the capitulum is wide and rectangular. The elongated upper articular process, the olecranon , stands out on the ulna , which has a short, compact shape . It takes up around 19% of the length of the total bone. The entire construction of the elbow joint shows that it is aimed at stabilizing the forearm and only allows limited lateral movements. The carpal bones are reduced in number, there may be no central os or fused with the navicular bone , sometimes there are also adhesions between the navicular and moon bones . The reduction in the number of carpal bones is similar to that of the burrowing tenreks and, like these, helps stabilize the hand while swimming. In contrast, a prepollex , a finger-like extension on the large polygonal bone , unlike the tenreks, is absent or greatly reduced in size. Instead, an extension appears on the navicular bone, which probably takes its position. Compared to the carpal bones, the metacarpal bones are extremely elongated.

The thigh bone is rather short in relation to the pelvis, which, in conjunction with the acetabulum that is oriented upwards, results in increased leg leverage. There is only a small third rolling hill on the femoral shaft, which, in contrast to the Tenreks, is shifted far down and thus supports a strong gluteal muscle. The shin and fibula are fused together in the lower third. Both bones are largely straight and are not clearly curved on the shaft. The structure of the ankle is very different from that of the tenreks. This applies to the elongated and narrow ankles , which restrict the ability of the foot to rotate. This is also caused by the sharp transition from the ankle roll to the joint neck on the ankle . The latter is also extremely short. Further striking differences can be found on the heel bone with its extremely long heel hump. At the foot, the metatarsal bones of the inner and outer rays are comparatively longer than those of the tenreks.

Soft tissues

As with the tenreks, the genital, digestive and excretory organs form a common outlet, the cloaca . The stomach is simply built and oval in shape. The intestine consisting of the small intestine and the large intestine reaches a total length of 55 cm in the Ruwenzori otter shrew , according to other information up to 68 cm, which corresponds to about four times the body length of the animal, the appendix is missing. The pancreas is very ramified. In the otter shrews, the testes are located in the pelvic area at the level of the pubic bone . They lie in fibrous skin pockets ( cremaster sacks ), which correspond to an inner pseudo scrotum . The position of the testicles differs from some tenreks like the rice treks , where they remain near the kidneys . The penis is comparatively long. Females have a two-horned uterus , and unlike tenreks , the placenta is endotheliochoric.

The brain of the otter shrew is relatively simple. It is noticeable by a reduction in the size of the olfactory bulb and an enlargement of the medulla oblongata . The trigeminal nerve originates from the latter and controls the whiskers, among other things. It is probably an adaptation to aquatic life in which the sense of touch, as the most important sense organ, replaces the sense of smell . The characteristics are least developed in the pygmy shrew and most strongly developed in the great otter shrew, which is interpreted as a gradual adaptation to the semi-aquatic way of life and is also reflected in other body characteristics. The volume of the brain is larger compared to the closely related tenreks. It varies between 720 and 1270 mg in the small otter shrews and between 3720 and 4640 mg in the large otter shrew.

distribution and habitat

Distribution areas of the three species of otter shrews

The otter shrews are endemic to central and western Africa . The great otter shrew has the largest range, it encompasses the entire Congo basin and includes the adjacent areas from eastern Nigeria in the north to Uganda in the east and to northern Angola and Zambia in the south. In the east it overlaps with that of the Ruwenzori otter shrew , which, however, only consists of a narrow strip west of the East African Trench from Lake Kivu to the Ruwenzori Mountains . The pygmy otter shrew lives separately from the other two species in the border area of Liberia , Ivory Coast and Guinea . The animals prefer tropical rainforests from sea level up to areas that are sometimes higher up to 2200 m. The habitat includes forest areas with small, slowly flowing and clear rivers or streams as well as ponds and marshland. The water temperatures are usually above 20 ° C, but in mountainous areas they can also drop to 12 ° C. As a rule, larger rivers are avoided.

Way of life

Territorial behavior and locomotion

The way of life of the otter shrews has hardly been studied. All three species are considered nocturnal, the active phase is interrupted by several short periods of rest. During the day, the animals retreat to burrows on the bank slopes. The burrows contain a nest chamber that is padded with leaves and other plant material. The animals are most likely solitary and do not or only rarely come together with other conspecifics except during the mating season. It is possible that there is territoriality among the individual individuals, which is indicated , among other things, by the deposit of faeces in special latrines. Characteristic is the scratching with the syndactyl toes of the hind foot, which is interpreted as comfort behavior .

With their characteristic physique, otter shrews are well adapted to a life in water. They move forward quickly by swimming. The swimming movements of the three types differ slightly from one another. In the case of the great otter shrew, sideways meandering movements of the body and, above all, the flattened tail ensure propulsion, the legs are placed against the body, the front legs only have a limited range of motion. In contrast, the Ruwenzori otter shrew paddles with its webbed front and rear feet. The tail has a rather rounded cross-section, but the undulating body movements are still preserved. The dwarf otter shrew with its rather small feet without webbed feet and also rounded tail combines both possibilities, it undulates with the body and the tail and occasionally paddles with the feet. In some cases, their ability to swim is assessed as being more original than the other two representatives. As a rule, the fur dries within a very short time after each water session. On land, the otter shrews walk on their soles, their tails dragging on the ground and drawing a straight line.

nutrition

All otter shrews have a carnivorous diet, they specialize primarily in crabs and fish . In addition, they also consume insects and frogs . but the latter are not preferred foods. The prey is mainly tracked down with the sense of touch , subordinate to the smell . To catch prey, the animals undertake short dives lasting a few seconds. As a rule, they kill their prey with bites, there is no manipulation with the front legs. They eat smaller prey directly in the water, but they also create larger prey on land. The smaller otter shrews in particular consume an amount of food that almost corresponds to their body weight.

Reproduction

Little is known about the reproduction of the otter shrews. Only in the dwarf otter shrew have births been observed in which up to four young were born. As nestlings, they are naked and blind. In the other two species, only pregnant females have so far been documented, which carried an average of two embryos . A pregnant female of the great otter shrew was accompanied by two young animals, so that at least two litters per year can be assumed. Female otter shrews have four pairs of teats : two in the chest and one in the abdomen and one in the groin area. Analogous to the Tenreks, no Graafian follicles develop during the development of the follicles .

Systematics

External system

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)







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The otter shrews form a family within the order of the tenre karts (Afrosoricida), which also includes the tenreks (Tenrecidae) and the golden mole (Chrysochloridae). The Tenreks are to be regarded as closest relatives, both groups together form the superordinate taxon of Tenrecomorpha . The Tenre-kartigen in turn belong to the superordinate order of Afrotheria , one of the four main lines within the higher mammals . The Afrotheria as a kinship community encompass various groups of animals , predominantly native to or originating from Africa . Their togetherness is based primarily on molecular genetic studies, less on anatomical similarities. Two major lines can be distinguished within the Afrotheria: the Paenungulata and the Afroinsectiphilia . The former include today's elephants , hyrax and manatees , the group has long been considered a common unit of descent. The latter line combines not only the tenre karts but also the elephant and the aardvark . The precise relationships between the last three groups mentioned have not yet been fully clarified. In some genetic studies there is a sister group relationship between the Afrosoricida and the elephants, both groups are then combined as Afroinsectivora. Others, on the other hand, see the tenre cardigans in a sister group position to all other Afrotheria, the elephants then show a closer relationship with the aardvark. According to the molecular genetic studies, the Afrotheria originated in the Upper Cretaceous 90.4 to 80.9 million years ago, their division into the two main groups began about 15 million years later. The Afrosoricida, in turn, formed shortly before the Cretaceous-Tertiary boundary about 68 million years ago. Around ten million later, the gold mole split off from the common line with the tenreks and the otter shrews. The separation of the latter two occurred in the Lower Eocene about 48 million years ago.

Internal system

Internal systematics of the otter shrews according to Everson et al. 2016
 Tenrecomorpha  
 Potamogalidae  
 Micropotamogale  

 Micropotamogale lamottei


   

 Micropotamogale ruwenzorii



 Potamogale  

 Potamogale velox



   

 Tenrecidae



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In contrast to the closely related Tenreks , which are restricted to Madagascar , the family of the otter shrews is not very diverse. Today it consists of three species in two genera . As a rule, the following structure is used:

  • Family Potamogalidae Allman , 1865

Common to all otter shrews is the absence of the collarbone , the syndactyle second and third ray of the hind foot, the two-rooted canine and the rather clear separation of the paraconus and metaconus on the molars of the upper jaw, which distinguishes them from the tenreks. In their general morphology, the three types of otter shrews are the same, but there are some significant deviations in detail, which, in addition to general size differences, are expressed in the shape of the tail, the presence or absence of webbed feet and special features of the teeth. Some of the mentioned differences in characteristics cause deviations in the way of life, for example in the swimming movement of the animals. The characteristic webbed feet of the Ruwenzori otter shrew induced Henri Heim de Balsac in 1956 to place the species in its own genus Mesopotamogale , which was not generally accepted. In some cases, however, reference is still made to the justification of Heim de Balsac's classification, which means that every species of otter shrew would have its own genus status.

Only one genus is currently recognized for fossils:

The status of the otter shrews has been assessed differently in the past. Sometimes they were considered an independent family, sometimes they were seen as a subfamily of the Tenreks. Some scientists also took a closer relationship with the web-footed tenrec ( Microgale mergulus on) which is also adapted to life in the water and how the Ruwenzori Otter Shrew has webbed feet. In 1957, Serge Frechkop proposed the subfamily Limnogalinae for the otter shrews and the water tenrek. In a skeletal anatomical study from 1999, Robert J. Asher came to the conclusion that the water tenrek is the sister taxon to the otter shrews. However, genetic studies confirmed the affiliation of the water tenreks to the Malagasy tenreks and thus the monophyly of the entire group. This is also shown by an analysis from 2016, which included all known representatives of the tenreks and otter shrews. She also comes to the conclusion that due to the early splitting off of the otter shrews from the Malagasy tenreks and sufficient morphological-anatomical differences in characteristics, a separate family status is justified for the former.

Research history

Taxonomy

George James Allman

The scientific name Potamogalidae used today for the otter shrews goes back to George James Allman , who coined it in 1866. Allman gave a comprehensive description of the morphological and skeletal anatomical characteristics of the great otter shrew and referred to the generic name Potamogale for the species. This in turn comes from Paul Belloni Du Chaillu from 1860. Du Chaillu did not define Potamogale , but noted the name only as a possible generic assignment. It was only through the publication of Allman's essay six years later that Potamogale could be scientifically established, at the same time he assigned the genus an independent family status. The reference to Allman 1865 as the first mention of the name is not undisputed. This is just an announcement of the new essay that was published a year later. However, since the family name is given in it, most authors have recently given 1865 as the year of origin.

A rather seldom used synonym is Mystomyidae by Edward Drinker Cope , which he introduced in 1883 due to the different molar design compared to the Tenreks. Mystomyidae, on the other hand, goes back to Mystomys , an alternative name to Potamogale by John Edward Gray from 1861. Gray established the new generic name because he saw Du Chaillus' first description of the great otter shrew as incorrect. Both Mystomys and Mystomyidae are not recognized today.

To the systematic position

Depiction of the great otter shrew from the French translation of Du Chaillus' travelogues from 1868

Du Chaillus' trip to central Africa in the 1850s led to the discovery of the great otter shrew. Their systematic position was, however, unclear. Du Chaillu saw connections to the crawling cats and thus to the predators , while Gray shifted them to the glires (the common group of rodents and rabbits ). Both assessments were based on insufficient material. It was not until the investigations of complete individuals by José Vicente Barbosa du Bocage and Allman in the mid-1860s that it was discovered that this is an insectivore-like animal. Barbosa du Bocage formulated a closer relationship with the Malagasy Tenreks (Tenrecidae), Allman, however, carried out a closer relationship with the sand weevils (Solenodontidae) that are common on some Caribbean islands . In his comprehensive review, A Monograph of the Insectivora, published in 1883, George Edward Dobson confirmed links to the tenreks and the slit weevers. For this he found similarities in the features of the skull and in the structure of the molars.

As a rule, this was hardly questioned in the course of the 19th and 20th centuries. The tenreks were already part of this when the taxon Insectivora was introduced by Thomas Edward Bowdich in 1821. Wilhelm Peters and Ernst Haeckel followed this up in the 1860s in their finer subdivision of the insectivores into the lipotyphla (without appendix) and the menotyphla (with appendix), the tenreks and the slit weevils belonging to the former. In 1885, Theodore Gill tried to reorganize insectivores and differentiated them according to the expression of the chewing pattern of the molars. In his view, there were two large groups of forms, on the one hand the zalambdodonta, which have a V-shaped enamel ridge on the molars (from the Greek ζα ( za- ) for an excess and the Greek letter Λ (lambda)), on the other hand the dilambdodonta with a W- shaped bar (from the Greek δι ( di "two"), and the Greek letter Λ (lambda)). He also paid attention to the otter shrews and put them together with the tenreks, the golden mole and the slit weevils to the zalambdodonta.

Two and a half decades later, William K. Gregory combined the structures of Haeckel and Gill in his work The orders of Mammals . He removed the menotyphla from the insectivores and led the rest of the group under the name Lipotyphla. He subdivided the lipotyphla into the Zalambdodonta with the otter shrews, the tenreks, the slit weevils and the golden mole as well as into the two large groups Erinaceomorpha (hedgehogs) and Soricomorpha (shrews and moles). Percy M. Butler varied this scheme in 1956. He only distinguished between the Erinaceomorpha and the Soricomorpha, the Tenreks (including the otter shrews) and the golden mole, he classified as the Soricomorpha. Leigh Van Valen, on the other hand, took a completely different view . He separated the zalambdodonta, i.e. the tenreks, otter shrews, golden mole and sand weevil, from the insectivores and referred them to the order of the Deltatheridia that he had created. Within this group, the Zalambdodonta stood opposite the so-called Hyaenodonta. In a more classic view, the latter belong to the “ Creodonta ” (“primal carnivores”), a large, but not self-contained group of predatory mammals. Van Valen's reorganization, however, was hardly shared. Subsequent authors kept the zalambdodont forms mostly in the insectivores and there in the Soricomorpha, such as Malcolm C. McKenna in the 1970s and Michael J. Novacek in the 1980s. McKenna repeated this view together with Susan K. Bell again in his overview work on the systematics of mammals in the 1990s, but in contrast to before he had excluded the gold mole from the Soricomorpha here.

Only in the transition from the 20th to the 21st century was it recognized by means of molecular genetic studies that the insectivores do not form a monophyletic group. Thus was the African branch with tenrecs and gold Mullen, plus the elephant shrews (Macroscelidea) and the aardvark (Tubulidentata) other original African animals such as elephants and hyraxes closer than the Eurasian part of insectivores. Michael J. Stanhope and colleagues therefore merged the African animals in 1998 in the taxon Afrotheria . Only a few years later, a research team led by Peter J. Waddell united the African insectivores within the Afrotheria under the name Afroinsectiphilia . The otter shrews were not included in these early genetic studies. The first gene sequencing here took place under Christophe J. Douady in 2002 and confirmed the close relationship with the Tenreks. Further analysis supported this view.

Tribal history

According to molecular genetic studies, the family of otter shrews reaches back at least to the Lower Eocene . Despite the long time span, fossil finds are extremely rare. In 2015, Martin Pickford described skull and dentition remains as well as individual parts of the musculoskeletal system of Namagale , a very primitive otter shrew that still has a clearly separated paraconus and metaconus on the upper molar teeth. As with the other representatives of the family, the canine has two roots and the rear molar is reduced in size. The finds come from the Eocliff site in the restricted area of Namibia . This is a travertine deposit that was formed in the Upper Eocene at the point where a calcareous spring emerged. Namagale would be the oldest known member of the otter shrews .

Mandibular remnant from Dilambdogale

No other unequivocal fossil finds are known. From the Fayyum area in Egypt , individual forms such as Dilambdogale , Widanelfarasia , Jawharia and Qatranilestes were known, which are usually only passed down through remains of teeth. For them, a closer relationship with the Afrosoricida can be assumed, which is expressed, among other things, in the zalambdodontic chewing surface pattern of the posterior maxillary molars. However, the foremost molar had a largely dilambdodontic pattern, which is reminiscent of the actual insectivore . The dating of the finds from the Fayyum ranges from the Upper Eocene to the Lower Oligocene . Younger finds from eastern Africa which are Protenrec and Erythrozootes be assigned and in the Lower Miocene belong. The found material consists of various remains of skulls and teeth. In their less developed zalambdodont molar pattern, they show similarities with the otter shrews, especially with the great otter shrews, and they were occasionally placed in their systematic proximity. Most authors see a closer position to the tenreks because of the single-rooted canine and some skull features. However, similar to the findings from Fayyum, a very basal position within the Afrosoricida was suggested.

Threat and protection

The loss of habitat through deforestation and expansion of agricultural areas as well as the reduction in water quality through the associated erosion , but also through construction activity, pose a threat to the individual populations of otter shrews . In addition, there is the hunting of their fur and the fact that animals are themselves sometimes caught in fishing nets and drowned. The IUCN lists one species, the pygmy otter shrew , as " near threatened ". This lives in a small area in western Africa, in which iron ore is intensively mined, which further restricts the habitat. The other two species, however, are not considered to be directly threatened. For all three representatives of the otter shrews, the IUCN also notes a potentially higher risk category, which the organization justifies with the decline in the population . All three species are present in protected areas.

literature

  • Ara Monadjem: Potamogalidae (Otter-shrews). 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. 174-179 ISBN 978-84-16728-08-4
  • Ronald M. Nowak: Walker's Mammals of the World . The Johns Hopkins University Press, Baltimore 1999, ISBN 0-8018-5789-9
  • 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

Individual evidence

  1. ↑ a b c W. N. Verheyen: Recherches anatomiques sur Micropotamogale ruwenzorii. 1. La morphologie external, les viscères et l'organe génital mâle. Bulletins de la Société Royale de Zoologie d'Anvers 21, 1961, pp. 1-16
  2. ^ A b Hans-Jürg Kuhn: On the knowledge of Micropotamogale lamottei. Zeitschrift für Mammalskunde 29, 1964, pp. 152-173
  3. ↑ a b c d e f g h i 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
  4. ↑ a b c d e f Ara Monadjem: Potamogalidae (Otter-shrews). 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. 174-179 ISBN 978-84-16728-08-4
  5. ^ A b c George J. Allman: On the characters and affinities of Potamogale, a genus of insectivorous mammals. Transactions of the Zoological Society of London 6, 1866, pp. 1–16 ( [1] )
  6. ↑ Hans-Jürg Kuhn: An Adult Female Micropotamogale lamottei. Journal of Mammalogy 52 (2), 1971, pp. 477-478
  7. ^ MR Sanchez-Villagra and RJ Asher: Cranio-sensory adaptations in small faunivorous semiaquatic mammals, with special reference to olfaction and the trigeminal system. Mammalia 66 (1), 2002, pp. 93-109
  8. ↑ Ch. Guth, Henri Heim de Balsac and M. Lamotte: Recherches sur la morphologie de Micropotamogale lamottei et l'evolution des Potamogalinae. I. Ecologie, denture, anatomie crânienne. Mammalia 23, 1959, pp. 423-447
  9. ^ 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
  10. ↑ a b c Ch. Guth, Henri Heim de Balsac and M. Lamotte: Recherches sur la morphologie de Micropotamogale lamottei et l'evolution des Potamogalinae. II. Rachis, viscéris, position systématique. Mammalia 24, 1960, pp. 190-216
  11. ^ A b George Edward Dobson: A Monograph of the Insectivora, systematic and anatomical. Part II. London, 1883, pp. 67–86 ( [2] )
  12. ^ Wilhelm Leche: On the history of the development of the mammalian tooth system, at the same time a contribution to the tribal history of this group of animals. Part two: phylogeny. Second booklet: Families of the Centetidae, Solenodontidae and Chrysochloridae. Zoologica 20, 1906/1908, pp. 1–157 ( [3] )
  13. ↑ a b W. N. Verheyen: Recherches anatomiques sur Micropotamogale ruwenzorii. 4. Observations ostéologiques et considérations générales. Bulletins de la Société Royale de Zoologie d'Anvers 22, 1961, pp. 1-7
  14. ^ Justine A. Salton and Eric J. Sargis: Evolutionary morphology of the Tenrecoidea (Mammalia) carpal complex. Biological Journal of the Linnean Society, 93, 2008, pp. 267-288
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