fossils are found in the lower part of the upper phosphatic unit. The kind of fossils that are usually used in biostratigraphy are rare, which complicates attempts at dating these beds, but "couche III" has been correlated with the late Maastrichtian on the basis of shark teeth, which has also been confirmed by carbon and oxygen isotope stratigraphy. The phosphates were deposited in an embayment of the eastern Atlantic Ocean that flooded North Africa during the Late Cretaceous and Early Paleogene. The area would have been part of the Tethys Sea at the time. The phosphatic matrix of the original Phosphatodraco specimen is gray and mottled with orange, and contained fossils including of the fish Serratolamna, Rhombodus, and Enchodus, and the mosasaur Prognathodon, as well as small nodules. The specimen was found close to skeletal remains of an indeterminate mosasaur, and remains of sharks, rays, fish such as Stratodus, mosasaurs such as Platecarpus, Mosasaurus, and Halisaurus, indeterminate elasmosaurid plesiosaurs, and indeterminate bothremydid turtles have also been found at the site. This assemblage of animals suggests the sediments were deposited in a marine environment. Other contemporary pterosaurs from the Ouled Abdoun Basin include the pteranodontid Tethydraco (if it is not the same animal as Phosphatodraco), the nyctosaurids Alcione, Simurghia, and Barbaridactylus, a small azhdarchid similar to Quetzalcoatlus, and a very large azhdarchid which may be Arambourgiania. Dinosaurs are rare there, but the abelisaurid Chenanisaurus, the hadrosaur Ajnabia, and sauropod fossils are also known. Longrich and colleagues suggested in 2018 that, although the fauna was overwhelmingly marine, the presence of terrestrial dinosaurs and azhdarchids indicates the coast was nearby. See also List of pterosaur genera Timeline of pterosaur research Pterosaur size References Bibliography Late Cretaceous pterosaurs of Africa Azhdarchids Fossil taxa described in 2003