Westlothiana

Westlothiana ("animal from West Lothian") is a genus of reptile-like tetrapod that lived about 338 million years ago during the latest part of the Visean age of the Carboniferous. Members of the genus bore a superficial resemblance to modern-day lizards. The genus is known from a single species, Westlothiana lizziae. The type specimen was discovered in the East Kirkton Limestone at the East Kirkton Quarry, West Lothian, Scotland in 1984. This specimen was nicknamed "Lizzie the lizard" by fossil hunter Stan Wood, and this name was quickly adopted by other paleontologists and the press. When the specimen was formally named in 1990, it was given the specific name "lizziae" in homage to this nickname.[1] However, despite its similar body shape, Westlothiana is not considered a true lizard. Westlothiana 's anatomy contained a mixture of both "labyrinthodont" and reptilian features, and was originally regarded as the oldest known reptile or amniote.[2] However, updated studies have shown that this identification is not entirely accurate. Instead of being one of the first amniotes (tetrapods laying hard-shelled eggs, including synapsids, reptiles, and their descendants), Westlothiana was rather a close relative of Amniota.[3] As a result, most paleontologists since the original description place the genus within the group Reptiliomorpha, among other amniote relatives such as diadectomorphs and seymouriamorphs.[4][5] Later analyses usually place the genus as the earliest diverging member of Lepospondyli, a collection of unusual tetrapods which may be close to amniotes or lissamphibians (modern amphibians like frogs and salamanders), or potentially both at the same time.[4]