Topic summary
Ludlow Bone Bed
Extracted from the Wikipedia article Ludlow Group.
Upper Ludlow sub-group
At the top of this sub-group a brown layer occurs, from a quarter of an inch to 4 in. (63 mm to 100 mm) in thickness, full of the fragmentary remains of fish associated with those of Pterygotus and mollusca. This layer, known as the "Ludlow Bone bed," has been traced over a very large area.