Many localities of the Ballagan Formation preserve exceptional fossils. The majority of fossiliferous sites are in the
Midland Valley (particularly the
Scottish Borders and
East Lothian), in the southeast corner of Scotland. One of the earliest sites to be studied was the fish bed at
Foulden, which hosts many well-preserved fish fossils, notably including endemic
actinopterygians (ray-finned fish) and the first complete skeleton of a
rhizodont. Plants and arthropods also form a significant portion of Foulden fossils. and further excavations were performed by
Stan Wood in 1980-1981. Willie's Hole, near
Chirnside, is another site known for its high quality of preservation. It was initially recognized for its
crustacean fossils, forming "shrimp beds" akin to those observed throughout the later Scottish Carboniferous. Tetrapod, fish, and arthropod fragments are common in several layers at Burnmouth, not just in fine-grained
overbank deposits Barrow Scar (near
Alwinton), and a borehole core at
Norham. Some sites are also found along the west coast of Scotland. Auchenreoch Glen, near
Dumbarton, was the collection site for the nearly complete type fossil of
Pederpes finneyae, which was the oldest named tetrapod of the Carboniferous upon its discovery. Diverse assemblages of fish teeth and other
microfossils have been found at
Ayrshire and at Hawk's Nib and Mill Hole, on the
Isle of Bute. == Paleobiota ==