The Oulad Abdoun Basin (also known as the Ouled Abdoun Basin or Khouribga Basin) is a phosphate sedimentary basin located in Morocco, near the city of Khouribga. It is the largest in Morocco, comprising 44% of Morocco's phosphate reserves, and at least 26.8 billion tons of phosphate. It is also known as an important site for vertebrate fossils, with deposits ranging from the Late Cretaceous (Maastrichtian) to the Eocene epoch (Ypresian), a period of about 25 million years.
Geography The Oulad Abdoun is located west of the Atlas Mountains, near the city of Khouribga. The Oulad Abdoun phosphate deposits encompass some , an area of . The Oulad Abdoun is the largest and northernmost of Morocco's major phosphate basins, which from northeast to southwest, include the Ganntour, Meskala, and Oued Eddahab (Laayoune-Baa) basins.
Paleobiota
The Oulad Abdoun Basin stretches from the late Cretaceous to the Eocene and contains abundant marine vertebrate fossils, including sharks, bony fish, turtles, crocodilians, and other reptiles, as well as sea birds and a small number of terrestrial mammals.
Molluscs Mollusca from the Khouribga Phosphates Genus Species Location Time Material Notes Images Cucullaea (Idonearca) C. (I.) thevestensis A false ark shell. Heligmopsis H. wegmanianus Maastrichtian A feather oyster also present in Ganntour basin. Venericardia V. coquandi Danian A carditid clam also present in Ganntour basin. Baculites B. sp. Maastrichtian A straight-shelled ammonite, also present in Ganntour basin. Cimomia C. aff. sudanensis Ypresian A nautiloid also present in Ganntour basin. Ampullinopsis A. crassatina An ampullinid gastropod. Hemithersitea H. chouberti Lutetian A thersiteid gastropod.
Fish Bony fish Bony fish from the Khouribga Phosphates Genus Species Location Time Material Notes Images Acipenseridae Indeterminate Maastrichtian First record of a sturgeon on the continent of Africa. Enchodus E. libycus Maastrichtian An enchodontid aulopiform. E. bursauxi Maastrichtian E. elegans Maastrichtian Eoserrasalmimus E. cattoi Maastrichtian A pycnodontiform. Mawsoniidae Indeterminate Maastrichtian A giant mawsoniid coelacanth measuring long. Phacodus P. punctatus var. africanus Maastrichtian A pycnodontiform. Plethodidae Indeterminate Maastrichtian Youngest occurrence of plethodid fish. Protarpon P. boualii Danian A tarpon Pycnodontidae Indeterminate Maastrichtian Pseudoegertonia P. sp. Maastrichtian Serrasalmimus S. secans Thanetian A carnivorous pycnodontiform. Stephanodus S. libycus Maastrichtian A pycnodontid Stratodus S. apicalis Maastrichtian An alepisauroform. Macroprosopon M. hiltoni Ypresian A marine osteoglossid.
Sharks Sharks from the Khouribga Phosphates Genus Species Location Time Material Notes Images Abdounia A. africana Selandian A requiem shark. Brachycarcharias B. atlasi Ypresian Casieria C. maghrebiana Selandian Chiloscyllium C. salvani. Selandian A carpet shark. Cretalamna C. appendiculata Maastrichtian An otodontid shark C. maroccana Maastrichtian Delpitoscyllium D. africanum Selandian Eostegostoma E. sp. Selandian A carpet shark. Foumtizia F. abdouni Selandian Galeorhinus G. mesetaensis Selandian A houndshark Ginglymostoma G. chenanei Selandian An early relative of nurse shark G. khouribgaense Selandian Hologinglymostoma H. jaegeri Selandian Khouribgaleus K. gomphorhiza Selandian Metlaouia M. delpiti Selandian Microscyliorhinus M. simplex Selandian Palaeogaleus P. larachei Selandian Palaeorhincodon P. daouii Selandian A carpet shark. Porodermoides P. spanios Selandian Premontreia P. peypouqueti Selandian P. subulidens Selandian Pseudocorax P. heteroserratus Maastrichtian A pseudocoracid mackerel shark Scyliorhinus S. ptychtus Selandian A catshark S. entomodon Selandian S. sulcidens Selandian Serratolamna S. serrata Maastrichtian A mackerel shark S. khderii Maastrichtian Squalicorax S. pristodontus Maastrichtian A crow shark S. bassanii Maastrichtian S. africanus Maastrichtian S. microserratus Maastrichtian S. benguerirensis Maastrichtian Triakis T. antunesi Selandian A houndshark
Other cartilaginous fish Other cartilaginous fish from the Khouribga Phosphates Genus Species Location Time Material Notes Images Archaemanta A. priemi Selandian A ray. Burnhamia B. cf. davisi Selandian A devil ray Coupatezia C. larivei Selandian A ray. C. fallax Maastrichtian C. elevata Maastrichtian Dasyatis D. ponsi Selandian A stingray. An indeterminate species found in Maastrichtian deposits of Ganntour Basin. Delpitia D. reticulata Selandian A ray. Gymnura G. delpiti Selandian A ray. Heterobatis H. talbaouii Selandian A ray. Heterotorpedo H. brahimi Selandian A ray. Hypolophodon H. sp. Selandian A ray. Rhombodus R. binkhorsti Maastrichtian A ray. R. microdus Maastrichtian R. meridionalis Maastrichtian Schizorhiza S. stromeri Maastrichtian A sclerorhynchoid skate which resembled a sawfish.
Dinosaurs
Ornithischians Ornithischians from the Khouribga Phosphates Genus Species Location Time Material Notes Images Ajnabia A. odysseus Office Cherifien des Phosphates mines at Sidi Chennane Maastrichtian partial left maxilla with teeth fragments of right maxilla partial right dentary A small lambeosaurine hadrosaur; the first known from Africa LambeosaurinaeIndeterminate Mrah LahrachMaastrichtian right femurA lambeosaurine larger than Ajnabia and MinqariaLambeosaurinaeIndeterminate Sidi DaouiMaastrichtian left humerusA lambeosaurine larger than Ajnabia and MinqariaMinqaria M. bata Sidi Chennane Maastrichtianright maxilla left dentary braincase A lambeosaurine hadrosaur Taleta T. taleta Sidi Chennane Maastrichtian partial left and right maxilla with teeth A lambeosaurine hadrosaur
Sauropods Sauropods from the Khouribga Phosphates Genus Species Location Time Material Notes ImagesPhosphatotitanP. khouribgaensis Sidi ChennaneMaastrichtian pelvis, caudal vertebrae, dorsal vertebrae, and sacral vertebrae.First named titanosaur from this region. Titanosauria Indeterminate Sidi Daoui Maastrichtianright femur, tibia, and fibula undescribed material An unnamed titanosaurian taxon with affinities to argentinosaurids, possibly slightly larger than Phosphatotitan.
Theropods
Abelisaurs Abelisaurs from the Khouribga Phosphates Genus Species Location Time Material Notes ImagesAbelisauridaeIndeterminate Sidi ChennaneMaastrichtianright tibiaProbably distinct from Chenanisaurus due to its smaller size (about long) despite being mature. Similar to South American abelisaurids. Possibly a member of Furileusauria. AbelisauridaeIndeterminate Sidi DaouiMaastrichtianright metatarsal IIA mature specimen but very small for an abelisaurid, about long Chenanisaurus C. barbaricus Sidi Chennane Sidi Daoui Maastrichtian anterior end of left dentary 2 premaxillary teeth a maxillary tooth A large abelisaurid theropod.
Birds Bird fossils are common in the Basin, which includes the oldest birds in Africa. At least three orders and several families of sea birds are represented, including Procellariiformes (albatrosses and petrels, fossils assignable to Diomedeidae and Procellariidae), Pelecaniformes (pelicans and allies, fossils assignable to Phaethontidae, Prophaethontidae, Fregatidae and Pelagornithidae), and Anseriformes (waterfowl, including fossil Presbyornithidae). Birds from the Khouribga Phosphates Genus Species Location Time Material Notes Images DasornisBourdon, Estelle & Amaghzaz, M'barek & Bouya, Baâdi. (2010). Pseudotoothed Birds (Aves, Odontopterygiformes) from the Early Tertiary of Morocco. American Museum Novitates. 3704. 1-71. 10.1206/3704.2. D. abdoun Sidi Daoui Ypresian A holotype specimens consists of carpometacarpus, ulna, radius, tibiotarsus, and humerus. A pelagornithid, or pseudotooth bird. D. emuinus Sidi Daoui Ypresian A partial skeleton with incomplete cranium. D. tolapica Selandian A parital skeleton. Lithoptila L. abdounensis Sidi Daoui Thanetian A neurocranium. A prophaethontid seabird related to modern tropicbirds.
Pterosaurs Pterosaurs from the Khouribga Phosphates Genus Species Location Time Material Notes Images Alcione A. elainus Sidi Daoui Maastrichtian A nyctosaurid which shows possible adaptations towards diving behaviour. Barbaridactylus B. grandis Sidi Daoui Maastrichtian A nyctosaurid. Simurghia S. robusta Sidi Daoui Maastrichtian A nyctosaurid related to Alcione. Phosphatodraco P. mauritanicus Sidi Daoui Maastrichtian An azhdarchid. Arambourgiania? Indeterminate Sidi Chennane Maastrichtian A giant azhdarchid, may belong to the Jordanian taxon Arambourgiania. aff. Quetzalcoatlus Indeterminate Maastrichtian Tethydraco T. regalis Sidi Daoui Maastrichtian A pterosaur of debated affinity; may be an azhdarchid or a pteranodontid.
Crocodylomorphs Crocodylomorphs from the Khouribga Phosphates Genus Species Location Time Material Notes Images Arambourgisuchus A. khouribgaensis Thanetian A dyrosaurid. Atlantosuchus A. coupatezi Danian A dyrosaurid. Chenanisuchus C. lateroculi Thanetian The most basal known dyrosaurid. Dyrosaurus D. maghribensis Ypresian A dyrosaur. Maroccosuchus M. zennaroi Ypresian A tomistomine crocodylian. Ocepesuchus O. eoafricanus Maastrichtian A gavialoid crocodylian.
Squamates
Mosasaurs The late Maastrichtian deposits of the Khouribga Phosphates preserve abundant mosasaur fossils, especially isolated teeth. At least fifteen species are represented, covering the majority of ecological niches the group is known to have occupied. The Ouled Abdoun Basin is one of the richest known mosasaur fossil sites in the world.
Mosasaurs from the Khouribga Phosphates Genus Species Location Time Material Notes Images Carinodens C. acrodon Maastrichtian Dentaries Isolated teeth A small mosasaurine mosasaur with crushing teeth. Fossils of all reported Carinodens species are very rare in Khouribga. The dentition differs slightly between species, suggesting marginally different diets. More fossil material is required to determine if both C. minalmamar and C. belgicus are present in the Khouribga Phosphates, as the present material is difficult to differentiate. C. belgicus Dentaries Isolated teeth C. minalmamar Dentaries Isolated teeth Eremiasaurus E. heterodontus Maastrichtian Partial and subcomplete skeletons Isolated teeth A mosasaurine mosasaur with unusually heterodont teeth, including straight and conical anterior teeth, blade-like median teeth, and recurved posterior teeth. A medium-sized (4.5–5 metres) predator and one of the more commonly found fossil mosasaurs in the Khouribga Phosphates. Gavialimimus G. almaghribensis Maastrichtian A complete skull Isolated teeth An unusual longirostrine plioplatecarpine mosasaur, measuring about 6 metres long. Fossils of G. almaghribensis are very common in the Khouribga Phosphates. Globidens G. phosphaticus Maastrichtian Isolated teeth A durophagous mosasaurine mosasaur with specialized crushing teeth. G. phosphaticus is known from Morocco only in the form of isolated teeth but more complete material from the species is known from Angola. G. phosphaticus and G. simplex were of similar size but had slightly different teeth, suggesting marginally different diets. G. simplex Maastrichtian A partial skull Isolated teeth Halisaurus H. arambourgi Maastrichtian Several skeletons