Scientific Classification
Kingdom Animalia
Phylum Chordata
Class Amphibia or Reptilia
Order Cotylosauria
Family Unknown
Genus Westlothiana
Species Westlothiana lizziae
Conservation Status
Westlothiana is a genus of reptile-like amphibians or possibly early reptiles that bore a superficial resemblance to modern-day lizards. It lived about 335 million years ago during the latest part of the Visean age of the Carboniferous period. It is known from a single species, Westlothiana lizziae. The type specimen was discovered in East Kirkton Quarry, West Lothian, Scotland in 1984. Westlothiana's anatomy contained a mixture of both labyrinthodont and reptilian features, and was originally regarded as the first reptile. Most scientists place them among the Reptilomorpha, as a sister group to the first amniotes.


This species probably lived near a freshwater lake and probably hunted for other small creatures that lived in the same habitat. It was a slender animal, with rather small legs and a long tail. Together with Casineria, another transitional fossil found in Scotland, it is one of the smallest reptile-like amphibians known, being a mere 20 centimeters in adult length. The small size has made it a key fossil in the search for the earliest amniote, as amniote egs are thought to have evolved in very small animals. Advanced features that ties it in with the reptilian rather than amphibian group is unfused ankle bones, lack of labyrinthodont infolding of the dentin, a lack of an otic notch and a generally small skull.

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