Marmorerpeton

Marmorerpeton is an extinct genus of prehistoric stem-salamanders that lived in Europe during the Middle Jurassic.[1] Remains are known from the Bathonian aged Forest Marble Formation of England and the Kilmaluag Formation of Scotland.[2] They are among the earliest-known salamanders,[3] and are probably older than Karaurus.[4][5] The teeth appear to have been weakly pedicellate. The genus appears to have been neotenic, based on a few morphological characters [1] and on the presence of calcified cartilage in the medulla of its humerus.[6]

Cross section of a Marmorerpeton femur in normal transmitted (left) and polarized (right) light

Marmorerpeton
Temporal range: Middle Jurassic, 167.7–164.7 Ma
↓
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Clade: Caudata
Genus: †Marmorerpeton
Evans et al. 1988
Type species
†Marmorerpeton freemani
Evans et al. 1988
Species
  • †M. freemani Evans et al. 1988
  • †M. kermacki Evans et al. 1988

The size of its osteocytic lacunae suggests that it had a fairly large genome (C-value of about 36.7 pg, with a 95% confidence interval ranging from 30.2 to 44.2 pg), though not as large as that of obligatorily neotenic extant urodeles. This suggests that it may have been facultatively neotenic.[7]

See also
  • List of prehistoric amphibians

References
  1. Evans, S. E.; Milner, A. R.; Mussett, F. (1988). "The earliest known salamanders (Amphibia, Caudata): a record from the Middle Jurassic of England". Geobios. 21 (5): 539–552. doi:10.1016/s0016-6995(88)80069-x.
  2. "Marmorerpeton". The Paleobiology Database. Retrieved 13 June 2010.
  3. Marjanovic, D.; Laurin, M. (2014). "An updated paleontological timetree of lissamphibians, with comments on the anatomy of Jurassic crown-group salamanders (Urodela)". Historical Biology. 26 (4): 535–550. doi:10.1080/08912963.2013.797972.
  4. "Fossil record". University of Bristol. Archived from the original on 29 February 2012. Retrieved 13 June 2010.
  5. Fraser, Nicholas C.; Sues, Hans-Dieter (1997-08-28). In the shadow of the dinosaurs: early Mesozoic tetrapods. Cambridge University Press. p. 16. ISBN 0-521-45899-4.
  6. de Buffrénil, V.; Canoville, A.; Evans, S. E.; Laurin, M. (2015). "Histological study of karaurids, the oldest known (stem) urodeles". Historical Biology. 27 (1): 109–114. doi:10.1080/08912963.2013.869800.
  7. Laurin, M.; Canoville, A.; Struble, M.; Organ, C.; de Buffrénil, V. (2015). "Early genome size increase in urodeles". Comptes Rendus Palevol. 15 (1–2): 74–82. doi:10.1016/j.crpv.2014.12.006.


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