Fossil vertebrates from the phosphate Basins of Morocco (Late Cretaceous-early Eocene)

Nathalie BARDET, Emmanuel GHEERBRANT, Nour-Eddine JALIL
UMR 7207, CR2P, Département Origine et Evolution, CNRS-MNHN-Sorbonne Université, Paris

The outstanding feature of the fossiliferous phosphate basins known in Morocco is the exceptional paleobiodiversity preserved locally during 24 Myr, from the Late Cretaceous to the Early/Middle Eocene. The Moroccan phosphate basins provide original data on the in situ evolution of marine and terrestrial faunas especially during the K/T and P/E major events in poorly known palaeobiogeographical provinces (South Atlantic, Southern Tethys margin, Africa).

The primary aim of the project is a palaeontological study by a multidisciplinary team of the exceptional local vertebrate faunas, especially those from the Ouled Abdoun and Ganntour basins, with research lines such as systematics, phylogeny, biostratigraphy, faunal evolution and turnover (especially during K/T and P/E transitions), palaeobiogeography and palaeoecology.

Coupled with the palaeontological research program, the project plans to gather and manage an international reference collection representative of the palaeobiodiversity of the vertebrate faunas from the phosphates basins of Morocco, relevant to research, education and exhibition. This collection, which constitutes a world-wide natural heritage of Morocco, is the basis for of a palaeontological museum project by the OCP in the mining center of Khouribga, with the support of the Department of the Galeries of the NMNH.

The pioneer palaeontological work of Arambourg (1952) revealed and popularized the extraordinary fossiliferous richness of the Moroccan phosphate basins. Even focused on selachian systematical studies for biostratigraphic purposes this study has shown that the phosphates fossils constitute the worldwide richest vertebrate marine fauna spanning the K/T boundary. Since this extensive Arambourg's monography, these fossiliferous sites curiously remained poorly explored and studied for decads, especially concerning the tetrapod faunas. Succeeding researches began in 1980's and also focused on selachians, with the works of H. Cappetta (USTL, Montpellier) and A. Noubhani (UCDJ, El Jadida) (e.g. Noubhani & Cappetta, 1997).

The unexpected discovery of the oldest known proboscidean Phosphatherium (Gheerbrant et al., 1996) in the Ouled Abdoun Basin renewed the interest of these fossiliferous sites.

It was indeed the first occurrence of continental vertebrates in these marine deposits. Nearly 60 years after Arambourg's first works (1934-1937), this exceptional discovery revived palaeontological researches in the phosphate basins of Morocco with the collaboration of the OCP. It allowed the opportunity to develop an official French-Moroccan paleontological research program in collaboration with several researchers from the MNHN, UCAM, UCDJ, and other Institutions (USTL Montpellier, UPV/EHU Bilbao).

Several French-Moroccan fieldwork campaigns have been developed between 1997 and 2010 in the Ouled Abdoun and Ganntour phosphate basins, resulting in important paleontological discoveries - especially for tetrapod taxa. They significantly improve our knowledge of local vertebrate faunas since C. Arambourg’s work.

Our team reported especially:

• the earliest known African ungulates and hyaenodont mammals (Gheerbrant et al., 1996, 1998, 2001, 2002, 2003, 2005, 2006, 2012, 2014, 2016; Gheerbrant 2009; Solé et al. 2009);
• new and exceptional material (skull and articulated skeletons) of well diversified marine reptile faunas, probably the richest from the K/T transition worldwide (Bardet et al., 2004a et b, 2005a et b;Hua & Jouve 2004; Jouve 2004, 2005, Jouve et al. 2005a et b);
• first known dinosaurs and pterosaurs from the Late Cretaceous of Morocco and Africa (Pereda Suberbiola et al., 2003, 2004);
• oldest known modern birds (Neornithes) from Africa, which are among the earliest representatives of the neornithine basal radiation (Gheerbrant et al., 2003; Bourdon 2003, 2004, 2005, 2006a, b, c;Bourdon et al. 2005, 2011);
• new and well preserved remains of osteichthyan teleosteans (Cavin et al., 2000; El Houssaini Darif 2007, Khalloufi et al. submitted).
• A Giant Late Cretaceous chelonioid turtle with a bony pipette-like snout, a suction feeding apparatus unique among Tetrapods (Bardet et al. 2013).

Fossils discovered in the phosphate basins of Morocco, and especially those of the Ouled Abdoun Basin, were the subject of two MNHN PhD theses, by S. Jouve (2004) on crocodilians, and E. Bourdon (2006) on birds. It was also part of the Habilitation theses of E. Gheerbrant (2001) and N. Bardet (2004).

Besides systematic and phylogenetic studies, works in progress focuse on:

• the chemostratigraphy of the Ouled Abdoun local phosphate series, in correlation with the selachian biostratigraphy by E. Gheerbrant, in collaboration with J. Yans (NDP, University of Namur), L. Kocsis (Universiti Brunei Darussalam), H. Cappetta (USTL, Montpellier), respectively. 
• the selachian and marine reptile biostratigraphy of the whole Late Cretaceous series of the Ganntour Basin by H. Cappetta (USTL, Montpellier), N. Bardet and X. Pereda Suberbiola (UPV/EHU, Bilbao). 
• the collected fossils are also at the heart of a museologic project managed by the OCP (OCP Museum).