Besano Formation

The Besano Formation is a geological formation in the southern Alps of northwestern Italy and southern Switzerland. This formation, a short but fossiliferous succession of dolomite and black shale, is famous for its preservation of Middle Triassic marine life including fish and aquatic reptiles. It is exposed in the vicinity of Monte San Giorgio and is among the formations responsible for the area being designated as a UNESCO World Heritage Site.
In Switzerland, it is also known as the Grenzbitumenzone.
Fossil content.
The formation is highly fossiliferous and has among others provided the following fossils: