Temporal range: early Carboniferous
Smithson and Rolfe, 1990
Westlothiana lizziae is an early tetrapod. It is a transitional fossil, with a mixture of amphibian and early amniote characters.282 Its body shape had a superficial resemblance to modern-day lizards. It lived during the Carboniferous period, about 350 million years ago.
Westlothiania in life[change | change source]
The small size has made it a key fossil in the search for the earliest amniote, as amniote eggs are thought to have evolved in very small animals. There are derived (advanced) features which tie it in with the amniotes rather than amphibians. These are: unfused ankle bones, lack of labyrinthodont infolding of the dentine in teeth, a lack of an otic notch and a generally small skull.
Phylogeny[change | change source]
Other websites[change | change source]
References[change | change source]
- Ruta M.; Coates M.I. & Quicke D.L.J. 2003. Early tetrapod relationships revisited. Biological Review 78: 251-345.PDF
- Smithson T.R. & Rolfe W.D.I. 1990. Westlothiana gen. nov.: naming the earliest known reptile. Scottish Journal of Geology 26, 137–138.
- Carroll R.L. 1991. The origin of reptiles. In: Schultze H.-P. & Trueb L. (eds) Origins of the higher groups of tetrapods — controversy and consensus. Ithaca: Cornell University Press. 331-353
- Laurin M. 2004. The evolution of body size, Cope's Rule and the origin of Amniotes. Systematic Biology 53 (4): 594-622. doi: 10.1080/10635150490445706 article
- Paton R.L; Smithson T.R. & Clack, J.A. 1999. An amniote-like skeleton from the early Carboniferous of Scotland. Nature 398: 508–513
- Palmer, D., ed. (1999). The Marshall illustrated encyclopedia of dinosaurs and prehistoric animals. London: Marshall Editions. p. 62. ISBN 1-84028-152-9.