Nasolo-Kleintenrek
| Nasolo-Kleintenrek | ||||||||||||
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| Microgale nasoloi | ||||||||||||
| Jenkins & Goodman , 1999 |
The Nasolo-Kleintenrek ( Microgale nasoloi ), sometimes also Nasolo- Kleintenrek , is a species of mammal from the genus of Kleintenreks within the Tenrek family . He is currently only known about four individuals from as many localities in the central and southwestern part of Madagascar . The species is also subfossilized from some cave sites. It is a medium-sized representative of the Kleintenreks. Like all Kleintenreks, it is characterized by a strong, spindle-shaped body and an elongated head with a narrow snout. The tail is slightly shorter than the rest of the body, the fur is particularly soft. The species mainly inhabits dry forests with dense undergrowth, which, however, are also subject to a certain humid influence. Little information is available about their way of life. The Nasolo Kleintenreks were first described in 1999. Its population is classified as threatened.
features
Habitus
The Nasolo-Kleintenrek is a medium-sized representative of the Kleinteinreks. Its head-torso length varies from 7.0 to 8.1 cm, the tail is 5.0 to 6.2 cm long and is thus slightly shorter than the rest of the body. The body weight varies from 5.9 to 14 g, with the weight given below coming from a young animal. Outwardly, the Nasolo Kleintenrek is similar to other Kleintenreks. It has a basically mouse-like shape with a spindle-shaped body, short, powerful limbs and a long head that tapered to the front. The tail appears thinner than most other small tenreks. The back fur is very soft and fine and gray in color. It gradually turns into a darker shade on the stomach. On the back, the individual hairs have gray bases and pale yellowish brown-gray tips, the tips of the hairs on the underside are somewhat darker. Guide hairs are characterized by gray bases, brown shafts and light gray tips. Brown tones predominate on the cheeks. The ears are 15 to 16 mm long, the eyes are moderately large. The tail is slightly darker gray on the upper side than on the underside, the fur here consists of long hair that covers the tail scales. Hands and feet each end in five rays, the top of the feet is covered with a light gray to yellowish brown fur. The length of the rear foot is 11-14 mm, which is relatively short. The central ray is the longest here, followed by the second and fourth laterally adjacent, the length of which is almost the same. The fifth toe is only slightly shorter, the first ending at the level of the base of the second. Females have a pair on the breast, two pairs on the abdomen, and a pair of mammary glands in the lumbar region .
Skull and dentition features
The skull measures 22.1 to 23.2 mm in length, at the cranium it is 9.0 to 9.2 mm wide. It is generally flattened, especially in the area of the posterior skull, the rostrum is wide and parallel. Behind the eyes there is an elongated constriction that narrows the skull to 4.1 to 4.3 mm wide. The occiput is short and falls in the direction of the longitudinal axis of the skull. It has a strong bulge in the area of the lambda seam. The lower jaw appears moderately robust, the crown process is noticeable due to its great width. The angular process, however, is short and narrow.
The dentition consists of 40 teeth, the tooth formula is. . In the front dentition, the rows of teeth run parallel to each other. The two inner incisors of the upper row of teeth are large, the front one surpasses the second. The third upper incisor is relatively small. In the lower jaw, however, the second incisor protrudes slightly over the first. The canine reaches the height of the front incisors both above and below. All front teeth are equipped with additional cusps. The molars have a zalambdodontic occlusal surface pattern with three main cusps each. The posterior upper premolar is very large, while the last ( molar ) has lateral narrowing. In the lower jaw, the last premolar and the two front molars are each almost the same size. The length of the upper row of teeth is 10.2 mm.
distribution
The Nasolo-Kleintenrek is endemic in central and southwestern Madagascar in the province of Toliara . So far only four individuals are known from as many localities. The sites in the southern part of the distribution area are the Forêt de Vohibasia , a 155 km² forest area 59 km northeast of Sakaraha , and the Forêt d'Analavelona , an isolated mountain range 12.5 km northwest of Andranoheza . Both sites are about 70 km apart in an east-west direction and have an altitude of 780 and 1050 m respectively. They were already known in the 1990s. It was not until the mid-2000s that two more sites were discovered significantly further north. They include the Forêt d'Amboropotsy 16.3 km northeast of Marofandilia and the Forêt de Lambokely 11 km north-northeast of Beroboka . Their altitudes only range from about 80 to 85 m. The four localities are spread over a relatively large area of 10,260 km², but this does not correspond to the actual occurrence of the species. While the Forêt de Vohibasia is characterized by dry and deciduous forests with dense undergrowth and crown heights of around 10 m, in the Forêt d'Analavelona to the east, the more humid influences of eastern Madagascar are already noticeable. The forests consist of hard-leaf vegetation , with fig and cherry myrtle plant communities dominating with heights of up to 25 m. The northern regions around the Forêt d'Amboropotsy and the Forêt de Lambokely are generally exposed to a more humid climate. Further field investigations in the vicinity of the four localities have so far not produced any evidence of the nasolo lesser tenreks. For this reason, it is assumed that the species occurs rarely in general.
Way of life
There is currently only limited information available on the way of life of the nasolo small tenreks. The animal from the Forêt de Vohibasia was caught in a tree at a height of 1.5 m above the ground. For morphological reasons, such as the rather short tail and the also short hind feet, the species represents a ground dweller. However, it obviously also has certain climbing abilities. The individual was also a pregnant female who carried three embryos , one in the right and two in the left horn of the uterus . Each of the embryos were approximately 10 mm long. The time of catching the animal, in mid-January, falls at the beginning of the rainy season. The season is characterized by a plentiful supply of food and, in the drier west of Madagascar, is the breeding period for various tenre maps. Several chitin shells from beetles and cockroaches were found in the trap of the animal from the Forêt d'Analavelona . In general, tenreks are insectivorous animals, so the remains can be interpreted as food leftovers.
Systematics
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Internal systematics of the Kleintenreks according to Everson et al. 2016
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The Nasolo-Kleintenrek is a kind from the genus of microgale ( Microgale ) within the family of tenrecs (Tenrecidae). The Kleintenreks belong to the subfamily of the Reistenreks (Oryzorictinae), which also includes the rice burrowers ( Oryzorictes ) and the representatives of the genus Nesogale . With more than 20 species, the Kleintenreks form the most diverse part of the family. Due to some morphological features, they are considered to be more originally within the Tenreks. According to molecular genetic analyzes, the genus was formed in the Lower Miocene around 16.8 million years ago and diversified considerably in the period that followed. Today's representatives show adaptations to different ways of life, so there are forms that dig underground, live above ground, or tree-climbing and water-dwelling forms. The greater part of the Kleintenreks live in the damp forests of eastern Madagascar, a few species also inhabit the drier landscapes of the western part of the island. Within the genus, different kinship groups can be identified both morphologically and genetically. The Nasolo-Kleintenrek is closely related to the Pale Kleintenrek ( Microgale fotsifotsy ) and the Shrew-Kleintenrek ( Microgale soricoides ).
Fossil finds of the Nasolo Kleintenreks are not known. However, there are various subfossil remains. The finds from the Ankilitelo cave on the southern edge of the Mikoboka plateau , also in southwestern Madagascar, should be emphasized . The rich fauna from the cave, which has been scientifically studied since 1994, includes various primates , bats and rodents as well as at least half a dozen species of tenreks. Several skulls and fragments of teeth have come down to us from the Nasolo-Kleintenrek. The finds are between 510 and 630 years old. Further remains of the Nasolo Kleintenreks came to light in the Andrahomana Cave in the extreme southeast of Madagascar. The cave has been known as a fossil store since the end of the 19th century, and its extremely rich fossil material spans the period of around 8,700 years. Both sites are outside of today's distribution area of the Nasolo-Kleintenreks. The surroundings of the Ankilitelo Cave are today characterized by a very dry climate, the Andrahomana Cave is located in the transition area from the dry areas of western to the humid zones of eastern Madagascar. The disappearance of the nasolo lesser tenreks and other small mammals in this region has various causes. It is partly related to the severe drying out of the southwestern part of the island. Other influencing factors can be found, among other things, in the progressive fragmentation of the forest areas since the human settlement of Madagascar 2000 years ago.
The first scientific description of the Nasolo Kleintenreks comes from Paulina D. Jenkins and Steven M. Goodman , it was published in 1999. Two individuals from the south-western arid regions of Madagascar formed the basis for listing the species . The holotype is represented by a fully grown female individual from the Forêt de Vohibasia , which was collected in mid-January 1996 at 780 m above sea level. The region therefore represents the type locality. The specific epithet nasoloi was assigned by the authors in honor of Nasolo Rakotoarison, who was the curator at the Botanical and Zoological Garden of the Madagascan capital Antananarivo and who was enthusiastic about mammals.
Threat and protection
The Nasolo-Kleintenrek is only known from four limited sites. The forest areas in which it is detected are subject to strong changes due to cattle breeding and exposure to fire. The IUCN therefore regards the species as "threatened" ( vulnerable ). It is represented in the Zombitse Vohibasia National Park and in a private nature reserve (Kirindy-CFPF) in the Forêt d'Amboropotsy . For the future, investigations into the size of the population , the extent of the distribution area and the behavior of the nasolo small tenreks are particularly necessary.
literature
- Paulina D. Jenkins and Steven M. Goodman: A new species of Microgale (Lipotyphla: Tenrecidae) from isolated forest in southwestern Madagascar. Bulletin of the Natural History Museum of London (Zoology) 65 (2), 1999, pp. 155-164
- Paulina D. Jenkins: Tenrecidae (Tenrecs and Shrew tenrecs). 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. 134–172 (p. 172) ISBN 978-84-16728-08-4
Individual evidence
- ↑ a b c d e f Paulina D. Jenkins and Steven M. Goodman: A new species of Microgale (Lipotyphla: Tenrecidae) from isolated forest in southwestern Madagascar. Bulletin of the Natural History Museum of London (Zoology) 65 (2), 1999, pp. 155-164
- ↑ a b c Voahangy Soarimalala and Steven M. Goodman: New distributional records of the recently described and endangered shrew tenrec Microgale nasoloi (Tenrecidae: Afrosoricida) from central western Madagascar. Mammalian Biology 73, 2008, pp. 468-471.
- ↑ a b c Paulina D. Jenkins: Tenrecidae (Tenrecs and Shrew tenrecs). 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. 134–172 (p. 172) ISBN 978-84-16728-08-4
- ^ A b P. J. Stephenson, Voahangy Soarimalala and Steven M. Goodman: Microgale nasoloi. The IUCN Red List of Threatened Species 2015. e.T62017A97200965 ( [1] ); last accessed on July 6, 2016
- ↑ a b c 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
- ^ JF Eisenberg and Edwin Gould: The Tenrecs: A Study in Mammalian Behavior and Evolution. Smithsonian Institution Press, 1970, pp. 1-138
- ^ RDE MacPhee: The Shrew Tenrecs of Madagascar: Systematic Revision and Holocene Distribution of Microgale (Tenrecidae, Insectivora). American Museum Novitates 2889, 1987, pp. 1-45
- ^ A b Kathleen M. Muldoon, Donald D. de Blieux, Elwyn L. Simons, and Prithijit S. Chatrath: The Subfossil Occurrence and Paleoecological Significance of Small Mammals at Ankilitelo Cave, Southwestern Madagascar. Journal of Mammalogy 90 (5), 2009, pp. 1111-1131
- ^ A b D. A. Burney, N. Vasey, LR Godfrey, Ramilisonina, WL Jungers, M. Ramarolahy and L. Raharivony: New Findings at Andrahomana Cave, Southeastern Madagascar. Journal of Cave and Karst Studies 70 (1), 2008, pp. 13-24
- ↑ Steven M. Goodman and William L. Jungers: Extinct Madagascar. Picturing the island's past. University of Chicago Press, 2014, pp. 1–206 (pp. 65–73 and 94–101)
- ↑ Voahangy Soarimalala: Les Afrosoricides de la forêt sèche malgache. Afrotherian Conservation 8, 2011, pp. 4-9
Web links
- Microgale nasoloi in the endangered Red List species the IUCN 2016 Posted by: PJ Stephenson, Voahangy Soarimalala and Steven M. Goodman, 2014. Accessed on 07/06/2016.