Discosauriscus

Discosauriscus
Temporal range: Gzhelian-Cisuralian
Discosauriscus austriacus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Order: †Seymouriamorpha
Family: †Discosauriscidae
Genus: †Discosauriscus
Kuhn, 1933
Species
  • Discosauriscus austriacus (Makowsky, 1876)
  • Discosauriscus pulcherrimus (Fritsch, 1879) (type)
Synonyms
  • Letoverpeton Spinar, 1952

Discosauriscus was a small seymouriamorph[1] which lived in what is now Central and Western Europe during the latest Carboniferous[2] and in the Early Permian Period. Its best fossils have been found in the Broumov and Bačov Formations of Boskovice Furrow, in the Czech Republic.

Classification

A reconstruction of a juvenile Discosauriscus with external gills
Fossil in Vienna

Discosauriscus belongs to the order Seymouriamorpha, and is the type genus of the family Discosauriscidae. Currently recognised are two valid species - Discosauriscus austriacus and Discosauriscus pulcherrimus. Letoverpeton is a junior synonym of Discosauriscus.[3]

Characteristics

Discosauriscids were long thought to be known from larval or neotenic forms,[4] and three ontogenetic stages had been distinguished.[5] However, more recent studies concluded that some subadult, probably terrestrial specimens were known,[6][7] so the case for neoteny in this taxon is not as well-supported as once thought. Discosauriscus had wide jaws with sharp teeth, short limbs and relatively long tail.[8] The phalangeal formula was 2-3-4-5-3 for both hind- and forelimbs. The body was covered with rounded scales with concentric rings, and a well-preserved lateral-line system has been described.[5]

Discosauriscus may have had electroreceptive organs.[9]

References

  1. ^ Panchen, A. L. and Smithson, T. R. 1988. The relationships of the earliest tetrapods. Pp. 1–32 in Benton, M. J. (ed), The Phylogeny and Classification of the Tetrapods, Volume 1: Amphibians, Reptiles, Birds. Clarendon Press, Oxford.
  2. ^ Klembara, J.; Werneburg, R.; Mikudíková, M.; Šurka, J.; Štamberg, S. (2023). "The oldest records of the stem amniote Discosauriscus (Seymouriamorpha, Discosauriscidae) from the European Carboniferous-Permian boundary". Bulletin of Geosciences. 98 (3): 233–246. doi:10.3140/bull.geosci.1882.
  3. ^ Klembara, Jozef (1997). "The cranial anatomy of Discosauriscus Kuhn, a seymouriamorph tetrapod from the Lower Permian of the Boskovice Furrow (Czech Republic)". Philosophical Transactions of the Royal Society of London, Series B. 352: 257–302. Bibcode:1997RSPTB.352..257K. doi:10.1098/rstb.1997.0021. PMC 1691931.
  4. ^ Carroll, R.L. 1988. Vertebrate Paleontology and Evolution, pp 176. WH Freeman and Company, New York ISBN 0-7167-1822-7
  5. ^ a b Klembara, Jozef. 1996. Discosauriscus. Version 1 January 1996. http://tolweb.org/Discosauriscus/17544/1996.01.01 in The Tree of Life Web Project, http://tolweb.org/
  6. ^ Sanchez, S; Klembara, J; Castanet, J; Steyer, JS (2008). "Salamander-like development in a seymouriamorph revealed by palaeohistology". Biology Letters. 4: 411–414. doi:10.1098/rsbl.2008.0159. PMC 2610144. PMID 18460423.
  7. ^ Kriloff, A.; Germain, D.; Canoville, A.; Vincent, P.; Sache, M.; Laurin, M. (2008). "Evolution of bone microanatomy of the tetrapod tibia and its use in palaeobiological inference". Journal of Evolutionary Biology. 21 (3): 807–826. doi:10.1111/j.1420-9101.2008.01512.x. PMID 18312321.
  8. ^ dinosaurier-news - Discosauriscus: Ein Amphibium aus der Permzeit Archived 8 July 2012 at archive.today
  9. ^ Klembara, J, Electroreceptors in the Lower Permian tetrapod Discosauriscus austriacus, Palaeontology, Vol 37, part 3, (1994)