East Kirkton Quarry is a former limestone quarry in West Lothian, Scotland, now better known as a fossil site known for terrestrial fossils from the fossil-poor Romer's gap, a 15 million year period at the beginning of the Carboniferous. The rocks and fossils are of Visean age, about 335 million years old. Best known are the labyrinthodont fossils, as the period coincides with the time where the modern lineages of tetrapods are thought to have evolved.
The quarry is located in the town of Bathgate in West Lothian, Scotland. Geologically, it sits fairly central to the middle of the fossil-rich Scottish Central Lowlands. The site is dominated by volcanic tuff and limestone, and layered silica deposits, indicating the presence of a hot spring associated with volcanism.
The land next to the quarry itself is developed for housing.
The quarry was most active in the 1830s and 1840s. During these years it yielded some interesting fossils of Carboniferous plants and eurypterids, though this was not uncommon for quarries in the area. When the quarry closed, the place was forgotten until fossil hunter Stan Wood found fossils of primitive tetrapods there in 1984. The quarry was bought by Wood for fossil collection, and yielded extremely interesting finds, including a huge sample of both terrestrial and marine fossil arthropods, examples of several classes of fishes and early amphibians. The latter include multiple examples of Balanerpeton (a temnospondyl), Silvanerpeton and Eldeceeon (basal anthracosaurs). A single specimen of a small animal named Westlothiana has variously been interpreted as an anthracosaur, a proto-amniote and possibly even the oldest known reptile.
- East Kirkton, Bathgate (GCR ID: 2757) in Dineley, D. and Metcalf, S. (1999) Fossil Fishes of Great Britain, Geological Conservation Review Series, No. 16, Joint Nature Conservation Committee, Peterborough, 675 pp. Chapter 15: Sites of British Fossil stem Tetrapoda and Amphibia. Retrieved 2014-04-08.
- White, T. & Kazlev, M.A. (2004): Paleozoic Sites, part 2 Archived 2010-11-26 at the Wayback Machine, from Palaeos website.
- Benton, M. (2005): Vertebrate Palaeontology 3rd edition. Blackwell Publishing
- Clack, J.A. (2002): Gaining ground: the origin and evolution of tetrapods. Indiana University Press, Bloomington, Indiana, USA. 369 pp
- "UKRIGS: East Kirkton Quarry". East Kirkton Quarry RIGS/SSSI. UKRIGS. Retrieved 3 September 2015.
- Smithson, T.R. & Rolfe, W.D.I. (1990): Westlothiana gen. nov. :naming the earliest known reptile. Scottish Journal of Geology no 26, pp 137–138.
- Ruta, M.; Coates, M.I. & Quicke, D.L.J. (2003): Early tetrapod relationships revisited. Biological Reviews no 78: pp 251-345.PDF
- Clack, Jennifer A. (2011). "A new microsaur from the early Carboniferous (Viséan) of East Kirkton, Scotland, showing soft tissue evidence". Special Papers in Palaeontology. 86: 1–11.