Microsauria
Microsauria |
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File:Microsauria.jpg | |
Microsauria diversity. (Hyloplesion (A), Pantylus (B), Pelodosotis (C) & Rhynchonkos (D)) | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Batrachomorpha |
Subclass: | †Lepospondyli |
Order: | †"Microsauria" Dawson, 1863 |
Subgroups | |
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Microsauria ("small lizards") is an extinct order of lepospondyl amphibians from the late Carboniferous and early Permian periods. It is the most diverse and species-rich group of lepospondyls.[1][2] Recently, Microsauria has been considered paraphyletic, as several other non-microsaur lepospondyl groups such as Lysorophia seem to be nested in it.[1][3][4] Microsauria is now commonly used as a collective term for the grade of lepospondyls that were originally classified as members of Microsauria.[2]
The microsaurs all had short tails and small legs, but were otherwise quite varied in form. The group included lizard-like animals that were relatively well-adapted to living on dry land, burrowing forms, and others that, like the modern axolotl, retained their gills into adult life, and so presumably never left the water.[5]
They are possible ancestors of the newts and salamanders, if that group did not arise from the temnospondyls along with the frogs and toads.[5]
Distribution
Microsaur remains have been found from Europe and North America in Late Carboniferous and Early Permian localities. Most North American microsaurs have been found in the United States in Arizona,[6] Texas, Oklahoma, Ohio,[7] Illinois, as well as Kansas and Nebraska,[8] although remains have also been found in Nova Scotia.[9] In Europe, microsaurs are known from Germany and the Czech Republic. Possible microsaur remains have also been found from strata in the town of Vyazniki in the Vladimir Oblast of Russia.[10] These strata are Late Permian in age, near the Permo-Triassic boundary. The microsaur material at Vyazniki may be the youngest record of microsaurs, and would extend their range by around 20 million years.
Classification
Cladogram modified from Anderson (2001):[3]
Lepospondyli |
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Cladogram from Ruta and Coates (2007):[4]
"Microsauria" |
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References
- ↑ 1.0 1.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Huttenlocker, A. K.; Pardo, J. D.; Small, B. J.; Anderson, J. S. (2013). "Cranial morphology of recumbirostrans (Lepospondyli) from the Permian of Kansas and Nebraska, and early morphological evolution inferred by micro-computed tomography". Journal of Vertebrate Paleontology 33 (3): 540.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
External links
- Microsauria in the Paleobiology Database