The celebrated fossil fish locality known as Lethen Bar, southeast of Nairn, Scotland, is a classic Middle Devonian locality which yielded beautifully preserved fossil fishes in nodules or concretions, which today can only be seen in museum collections. Some of these fishes were new species which contributed significantly to the work of fish expert Louis Agassiz of Switzerland. The locality was largely centred on limestone quarries situated around an outlier of the main fish bed and was first mapped in 1839 by Dr John Grant Malcolmson who employed contemporaneous methods and presentation styles which unfortunately, were to mislead some 19th and 20th century workers. In 1878 the area was mapped far more accurately by Dr John Horne leading a team from the BGS, producing a detailed geological map in 1923 which superseded Malcolmson’s work.
In 1983 the most recent author, Dr Mahala Andrews, proposed that the locality has been lost since the late 19th century mainly due to her analysis of Malcolmson’s account from which she derived a hypothesis of a continuous method of extraction resulting in exhaustion of the outcrop. This legacy of contradictory information was to muddy the waters for those who followed, especially those seeking the quarries which yielded the most celebrated specimens. Since Andrews 1983 paper attempts have been made to rediscover the outcrop, including heavy excavation, with little or no success and no new publication.
In 2005 a small team of enthusiasts lead by Prof Nigel Trewin investigated the main outcrop in a newly re-opened 19th century quarry and produced the first scientifically detailed stratigraphical section of the fish bed and this was followed in 2021 and 2022 by detailed field surveys and literature review. Here we present a reconciliation of past accounts and revealing new information on the locations of the old quarries.