Dinosaur footprints and other Ichnofauna from the Cretaceous Kem Kem Beds of Morocco

Abstract

We describe an extensive ichnofossil assemblage from the likely Cenomanian-age 'lower' and 'upper' units of the 'Kem Kem beds' in southeastern Morocco. In the lower unit, trace fossils include narrow vertical burrows in cross-bedded sandstones and borings in dinosaur bone, with the latter identified as the insect ichnotaxon Cubiculum ornatus. In the upper unit, several horizons preserve abundant footprints from theropod dinosaurs. Sauropod and ornithischian footprints are much rarer, similar to the record for fossil bone and teeth in the Kem Kem assemblage. The upper unit also preserves a variety of invertebrate traces including Conichnus (the resting trace of a sea-anemone), Scolicia (a gastropod trace), Beaconites (a probable annelid burrow), and subvertical burrows likely created by crabs for residence and detrital feeding on a tidal flat. The ichnofossil assemblage from the Upper Cretaceous Kem Kem beds contributes evidence for a transition from predominantly terrestrial to marine deposition. Body fossil and ichnofossil records together provide a detailed view of faunal diversity and local conditions within a fluvial and deltaic depositional setting on the northwestern coast of Africa toward the end of the Cretaceous