South Threave

Also within

Ayrshire and Arran County

Condition (NatureScot)

Geology & landscape

Geological Period: Ordovician

Description

South Threave South Threave, lying 3km north west of Dailly, exposes some of the youngest Ordovician rocks of the Girvan area. They date from around 435 million years ago and include the world-famous Lady Burn Starfish Beds of the Ashgill Drummuck Group, which contain a well preserved fossil fauna of unrivalled diversity. The fossil fauna of the Ladyburn Starfish Beds, known only from this site, represents virtually all the main groups of late Ordovician marine animals and is of international palaeontological and stratigraphical interest. South Threave is the type-locality (location of first discovery) for several cystoid, asteroid and echinoid species, and has also yielded holothurians. The well-preserved echinoderm material has been of particular interest in the study of the early representatives of this important extant phylum. The site is the most important Ordovician crinoid locality in Britain – a third of known species being solely from this locality. In addition to echinoderms, the shelly fauna includes brachiopods, and trilobites. The strata formed as a result of catastrophic movements of the sediments and organisms into deeper water and thus represents a series of instant ‘census’ events at a time of major global faunal change.