Top beautiful specimen. Dermal plate of an indeterminate crocodile from the Upper Cretaceous. They are characterized very well for their ornamentation very well marked. Specimen without preparation or cleaning. It still has most of its surface covered by gravelly sandy sediment. This specimen is perfect to practice its surface cleaning and discover its wonderful ornamentation.
The teeth and bones with strong and vivid fossilization colors such as red, orange and black come from small paleochannels composed by thin layers, in the intermediate and upper stratigraphic levels (Red Sandstone Beds), from the Aoufous and Ifezouane Formations (Kem Kem Basin, South of Morocco). The lithology of this body of sediment is characterized by the dominance of sandstones (also known as arenites) and fluvial gravel, of siliceous nature. Sometimes large concentrations of iron oxide are present, and then a small sample of that is usually present at the base of the tooth. These mineralizations are responsible for the wide range of beautiful reddish color tones, slowly drawn during millions of years via fossil-diagenetic processes. The complicated sedimentarian architecture of the layers where most large vertebrates are found makes the excavation methodology a real challenge. Sometimes the local miners have to excavate long tunnels that follow the distribution of the fossiliferous layer.
The crocodile rests represent a high percentage of the faunal association of the Cretaceous in the north of Morocco. However, its specific identification presents an enormous complexity. Even the genus identification is very complicated if only dentition rests are available. Many fossil sellers that work with pieces from this area, label their crocodile teeth as belonging to the huge crocodile of the Sarcosuchus sp genus --however, it is not present in this zone of Africa.
Next we will list the crocodile species described so far in the north African Cretaceous:
- Aegisuchus witmeri (Holliday & Gardner, 2012)
- Araripesuchus rattoides (Sereno & Larsson, 2009)
- Elosuchus cherifiensis (Lavocat, 1955)
- Hamadasuchus rebouli (Buffetaut, 1994)
- Kemkemia auditorei (Cau & Maganuco, 2009)
- Laganosuchus maghrebensis (Sereno & Larsson, 2009)
During the Upper Cretaceous the north of Africa was a humid region close to the Sea of Tetis, a maritime way between the austral continents of Gondwana and the terrestrial boreal masses of Laurasia. At this time, the sediments of the Kem Kem Formation in Morocco were deposited in a fresh water delta system. All the crocodylomorpha lived in this delta next to fish, turtles, snakes and varanidae lizards, ptesoraurs and sauropod dinosaurs, and theropods. All of them can be considered riverside predators. Their potential preys included coelacanths and lungfish, of which fossils have been found in the Kem Kem layers.
The Upper Cretaceous was an important period in the evolution of the crocodiles because many terrestrial masses were splitting What is now Europe and Asia was moving away from Africa, forming the Tetis Sea. In the meanwhile, North America continued separating from the rest of Laurasia, as the Atlantic ocean was widening.