These are distinguishable from the grey Chalk coprolites by their brownish ferruginous colour and smooth appearance.
Coprolites have been found at Lyme Regis, enclosed by the ribs of ichthyosauri, and in the remains of several species of fish; also in the abdominal cavities of a species of fossil fish, Macropoma Mantelli, from the chalk of Lewes.
Jager has described coprolites from the alum-slate of Gaildorf in Wurttemberg; the fish-coprolites of Burdiehouse and of Newcastle-under-Lyme are of Carboniferous age.
The bone-bed of Axmouth in Devonshire and Westbury and Aust in Gloucestershire, in the Penarth or Rhaetic series of strata, contains the scales, teeth and bones of saurians and fishes, together with abundance of coprolites; but neither there nor at Lyme Regis is there a sufficient quantity of phosphatic material to render the working of it for agricultural purposes remunerative.
The term coprolites has been made to include all kinds of phosphatic nodules employed as manures, such, for example, as those obtained from the Coralline and the Red Crag of Suffolk.