Spiny billy
| Spiny billy | ||||||||||||
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South Indian Stachelbilch ( Platacanthomys lasiurus ) |
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| Platacanthomyidae | ||||||||||||
| Alston , 1876 |
The stachelbilche (Platacanthomyidae), also known as "thorn hyrax", are a family of rodents belonging to the mice . With the South Indian stachelbilch and the Chinese dwarf bilch , they are common in southern and southeastern Asia . On the basis of tooth characteristics, they were often assigned to the dormice in the past , to which the two very different tree-dwelling species also resemble externally, especially because of their bushy tails.
Characteristic within the mice are the brush-like tail, the notches on the upper incisors, the flat chewing surfaces of the molars, whose enamel pattern is formed by parallel, oblique rows of elongated ridges and valleys, the small muscle process of the lower jaw, the enlarged foramina palatina posteriora between the first upper molars, the merging of the foramen palatinum dorsale with the foramen sphenopalatinum , the absence of an foramen ovale accessoryium as well as the great foramen maxillare posterius .
anatomy
Exterior
Stachelbilche are relatively small mice with a bilch-like build. Their head-trunk length is 118 to 140 millimeters in the South Indian stachelbilch and 70 to 89 millimeters in the Chinese dwarf bilch. The slightly bushy tail of the South Indian Stachelbilch is shorter than the length of the head and torso, whereas it is longer in the Chinese dwarf bilch. The back two-thirds of the tail resemble a bottle brush. The fur of the South Indian Stachelbilch is prickly, whereas it is dense and soft in the Chinese dwarf bilch. The whiskers on the snout are long. The paws are small and slender and the toes are moderately long. There are four toes with claws and a rudimentary thumb with a nail on the front paws, and there are five toes on the rear paws. The soles of the front and rear paws are bare and have six pads . The females of the South Indian Stachelbilch have two pairs of teats and those of the Chinese dwarf bilch have four.
Skull and teeth
The skull of the stachelbilche has a short snout compared to the brain skull . The zygomatic arches are moderately strong or thin and delicate. The zygomatic arch plates are narrow to moderately wide and their front edge is curved inward. The infraorbital foramen is large and narrow, and the posterior maxillary foramen is also large. The interorbital region and the parietal bone are wide and the occiput is deep. In relation to the skull, the tympanic bladders are small and they do not have any continuous partitions ( septum ). The mastoid of the temporal bone is slightly inflated and not broken through windows. The squamosomastoid foramen is small and limited to the suture between the scaly bone and the mastoid. The stapedial foramen is small or absent. The bony palate is broad and ends in front of the rear edge of the molar rows. The foramina incisiva are short and between the first upper molars the bony palate is pierced by two enlarged foramina palatina posteriora . The dorsal palatine foramen is fused with the sphenopalatine foramen . The mesopterygoid fossa is wide. The pterygoid fossae are also wide, flat, smoothly merge with the sides of the skull, and are intact or have small holes. The foramen buccinatorium and the forum masticatorium are fused together and a foramen ovale accessorium is missing. The medium lacerum foramen is small and fused with the moderately large postglenoidal foramen , or it is tiny and separate from the small postglenoidal foramen . The alisphenoid forms the lateral surface of the alisphenoideus canal . The lower jaw is small and delicate. Its low and angular muscle process is usually only slightly higher than the articular process. The angular process is neither bent inward nor broken through.
| 1 | · | 0 | · | 0 | · | 3 | = 16 |
| 1 | · | 0 | · | 0 | · | 3 |
In each half of the jaw, the dentition of the stachelbilche has an incisor tooth designed as a incisor tooth and three low-crowned , yoke-toothed molars . The upper incisors form a right angle with the skull . They have no furrow, but are notched. The enamel of the front teeth is orange. In the South Indian stachelbilch, the upper rows of molars converge slightly at the front and in the Chinese dwarf bilch they run parallel to each other. The second upper and lower molars are about the same size or slightly smaller than the first, and the third is about a third smaller than the other two. The upper molars have three roots and the lower ones have two. Your chewing surface is flat and the enamel pattern is formed by parallel, sloping rows of elongated ridges and valleys. The ridges and valleys of the third molar are almost transverse instead of oblique.
Internal organs
The South Indian stachelbilch lacks an appendix . The Chinese dwarf bilch is small.
Habitat and Distribution
The habitat of the tree-dwelling stachelbilch are rocky mountain gorges up to a height of 900 meters above sea level with the South Indian stachelbilch and mountain forests up to a height of 1200 meters or higher with the Chinese dwarf bilch. Their distribution area extends over the southwest of India as well as the southeast of China and the north of Vietnam .
Tribal history
Although today characterized by many derived features , spiny billy are recognizable as such from the lower Miocene . Since they differ strikingly in their tooth features from cricetid mice of the Miocene, they probably split off during the Eocene or Oligocene . The enamel pattern of their molars and their relative size to each other could be derived from a basic plan similar to that of Eucricetodon . They probably originated in Asia and came to Europe and as far as Spain in the Miocene as the genus Neocometes . Fossil species of the genera Platacanthomys and Typhlomys are known from China from the Miocene onwards. It is doubtful, however, whether a 17 million year old find from the Siwaliks in northern Pakistan can be assigned to the stachelbilchen.
Systematics and nomenclature
External system
According to molecular genetic studies of the nuclear IRBP and GHR genes, the stingray are the sister group of all other recent mice and not closely related to the dormouse . Morphological features, including the only three molars in each half of the jaw, the small tympanic sacs without continuous partitions, and the angular process of the lower jaw that is neither inwardly curved nor perforated, indicate that it belongs to the mouse-like family . The enamel pattern of the molars also differs in important details from that of the dormouse and is more similar to that of the Malagasy Voalavoanala . The melt strips in the spiny billets run diagonally and not across as in the billets.
On the surface, however, the melting patterns are similar and so the stachelbilche have often been assigned to the dormouse or placed in their vicinity since the first description of the South Indian stachelbilch in 1859 by Edward Blyth . Wilhelm Peters , on the other hand, brought them into connection with the mouse species as early as 1865. Samuel Schaub and Helmut Zapfe showed in 1951 that the valleys in the melt pattern do not correspond to those of the dormice , but that the melt pattern can be derived from the cricetid basic plan. In 1953 they assigned the stachelbilche to the rooters .
Internal system
One fossil and two recent genera of the stachelbilche with several fossil and five recent species can be distinguished:
- † Neocometes Schaub & Zapfe, 1953
- † Neocometes orientalis Mein, Ginsburg & Ratanasthien, 1990 from the Miocene of Thailand
- † Neocometes similis Fahlbusch, 1966 from the Miocene of Europe
- † Neocometes brunonis Schaub & Zapfe, 1953 from the Miocene of Europe
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Typhlomys Milne-Edwards, 1877
- † Typhlomys primitivus Qiu, 1989 from the Miocene of China
- † Typhlomys intermedius Zheng, 1993 from the Pliocene of China
- † Typhlomys hipparionium Qiu, 1989 from the Miocene of China
- † Typhlomys macrourus Zheng, 1993 from the Pliocene of China
- Chinese dwarf bilch or China dwarf bilch , Typhlomys cinereus Milne-Edwards, 1877 in southeast China.
- Dalou Shan dwarf goblet Typhlomys daloushanensis Wang Yingxiang & Li Chongqiung, 1996 in Central China.
- Dwarf bilch , Typhlomys nanus Cheng Feng et al., 2017 in southwest China.
- Vietnam dwarf bilch , Typhlomys chapensis Osgood, 1932 in southwest China and northwest Vietnam.
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Platacanthomys Blyth, 1859
- † Platacanthomys dianensis Qiu, 1989 from the Miocene of China
- South Indian Stachelbilch , Platacanthomys lasiurus Blyth, 1859 in southwest India
The genera Neocometes and Typhlomys are morphologically similar. Platacanthomys , on the other hand, has more derived tooth features and represents a separate branch of development. The differences between Typhlomys and Platacanthomys are so great that Sergei Ivanovich Ognew led them in 1947 in independent subfamilies of the dormouse.
nomenclature
The subfamily Platacanthomyinae with the type genus Platacanthomys was established in 1876 by Edward Richard Alston . Gerrit Smith Miller and James Williams Gidley introduced the family Platacanthomyidae in 1918 and Sergei Ivanovich Ognew in 1947 the tribe Platacanthomyini. The subfamily Typhlomyinae with the type genus Typhlomys was established by Ognew in 1947.
Web links
literature
- Michael D. Carleton, Guy G. Musser: Muroid rodents . In: Sydney Anderson, J. Knox Jones jr. (Ed.): Orders and Families of Recent Mammals of the World . John Wiley & Sons, New York a. a. 1984, ISBN 0-471-08493-X , pp. 289-379 .
- Fritz Dieterlen: Further subfamilies of the Wühler . In: Bernhard Grzimek (Ed.): Grzimek's Enzyklopädie Säugetiere. Volume 5 . S. 266-275 ( undated [1988], eleven-volume licensed edition).
- John Reeves Ellerman: The Families and Genera of Living Rodents. Volume I: Rodents Other Than Muridae . Trustees of the British Museum (Natural History), London 1940 ( BHL : 34542 - 689 pages).
- Sharon A. Jansa, Thomas C. Giarla, Burton K. Lim: The phylogenetic position of the rodent genus Typhlomys and the geographic origin of the Muroidea . In: Journal of Mammalogy . tape 90 , no. 5 , 2009, p. 1083-1094 , doi : 10.1644 / 08-MAMM-A-318.1 .
- Lee Young-Nam, Louis L. Jacobs: The platacanthomyine rodent Neocometes from the Miocene of South Korea and its paleobiogeographical implications . In: Acta Palaeontologica Polonica . tape 55 , no. 4 , 2010, p. 581-586 , doi : 10.4202 / app.2010.0013 .
- Wolfgang Maier: Rodentia, rodents . In: Wilfried Westheide, Reinhard Rieger (Ed.): Special Zoology. Part 2: vertebrates or skulls . Spectrum Academic Publishing House (Elsevier), Heidelberg / Berlin 2004, ISBN 3-8274-0307-3 , p. 531-547 .
- Malcolm C. McKenna, Susan K. Bell: Classification of Mammals Above the Species Level . Columbia University Press, New York 1997, ISBN 0-231-11012-X (631 pages).
- Guy G. Musser, Michael D. Carleton: Superfamily Muroidea . In: Mammal Species of the World: A Taxonomic and Geographic Reference . 3. Edition. Johns Hopkins University Press, Baltimore 2005, ISBN 0-8018-8221-4 , pp. 894–1531 ( online version ).
Remarks
- ↑ Dieterlen, 1988 (p. 266)
- ↑ Maier, 2004 (p. 541)
- ↑ a b c Carleton & Musser, 1984 (pp. 364–365)
- ↑ Carleton & Musser, 1984 (p. 365)
- ↑ Carleton & Musser, 1984 (pp. 365-366)
- ^ Ellerman, 1940 ( p. 626 )
- ↑ Carleton & Musser, 1984 (p. 366)
- ↑ a b c d e Musser & Carleton, 2005 ( Platacanthomyidae , pp. 905–906)
- ↑ Lee and Jacobs, 2010 (p. 584)
- ↑ Jansa and colleagues, 2009 (p. 1083)
- ↑ Carleton & Musser, 1984 (p. 368)
- ^ Ellerman, 1940 ( p. 627 )
- ^ McKenna and Bell, 1997 (p. 172)
- ↑ Musser & Carleton, 2005 ( Typhlomys , p. 906)
- ↑ Musser & Carleton, 2005 ( Platacanthomys , p. 906)