Coprolites from the Maastrichtian Whitemud Formation of southern Saskatchewan: Morphological classification and interpretation on diagenesis

Alluvial floodplain mudstones of the late Maastrichtian Whitemud Formation of southern Saskatchewan contain abundant vertebrate faecal remains preserved as siderite and Fe-hydroxides. The coprolites are grouped into nine morphological classes on the basis of style of coiling, shape, size, and striations. Their morphology is consistent with deposition of the faeces by terrestrial reptiles and not by fish as previously reported. The excellent preservation of the fossils can be attributed to early diagenetic precipitation of Fe CO3 in loci where faecal matter was still bacterially fermenting.