Microsauria

Microsauria
Temporal range: Late Carboniferous-Early Permian, 318.1–270.6 Ma
Microsauria diversity. (Hyloplesion (A), Pantylus (B), Pelodosotis (C) & Rhynchonkos (D))
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Superclass: Tetrapoda
Order: †Microsauria
Dawson, 1863
Subgroups

Microsauria ("small lizards") is an extinct, possibly polyphyletic[1] order of tetrapods from the late Carboniferous and early Permian periods. It is the most diverse and species-rich group of lepospondyls.[2][3] Recently, Microsauria has been considered paraphyletic, as several other non-microsaur lepospondyl groups such as Lysorophia seem to be nested in it.[2][4][5] Microsauria is now commonly used as a collective term for the grade of lepospondyls that were originally classified as members of Microsauria.[3]

Microbrachis

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.[6] Their skeleton was heavily ossified, and their development was likely gradual with no metamorphosis.[7]

  1. ^ Mann, Arjan; Gee, Bryan M.; Pardo, Jason D.; Marjanović, David; Adams, Gabrielle R.; Calthorpe, Ami S.; Maddin, Hillary C.; Anderson, Jason S. (2020). "Reassessment of historic 'microsaurs' from Joggins, Nova Scotia, reveals hidden diversity in the earliest amniote ecosystem". Papers in Palaeontology. 6 (4): 605–625. doi:10.1002/spp2.1316. S2CID 218925814.
  2. ^ a b Ruta, M.; Coates, M.I.; Quicke, D.L.J. (2003). "Early tetrapod relationships revisited" (PDF). Biological Reviews. 78 (2): 251–345. doi:10.1017/S1464793102006103. PMID 12803423. S2CID 31298396.
  3. ^ a b Bolt, J.R.; Rieppel, O. (2009). "The holotype skull of Llistrofus pricei Carroll and Gaskill, 1978 (Microsauria: Hapsidopareiontidae)". Journal of Paleontology. 83 (3): 471–483. Bibcode:2009JPal...83..471B. doi:10.1666/08-076.1. S2CID 128436286.
  4. ^ Anderson, J.S. (2001). "The phylogenetic trunk: Maximal inclusion of taxa with missing data in an analysis of the Lepospondyli (Vertebrata, Tetrapoda)". Systematic Biology. 50 (2): 170–193. doi:10.1080/10635150119889. PMID 12116927.
  5. ^ Ruta, M.; Coates, M.I. (2007). "Dates, nodes, and character conflict: addressing the lissamphibian origin problem". Journal of Systematic Palaeontology. 5: 69–122. doi:10.1017/S1477201906002008. S2CID 86479890.
  6. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 55. ISBN 978-1-84028-152-1.
  7. ^ Herpetology: An Introductory Biology of Amphibians and Reptiles