Subject Area
Earth, Atmospheric and Marine Sciences
Abstract
The Koum basin is located in West Africa and is a halfgraben filled with Cretaceous and younger sediments. It formed in response to tectonic stresses that preceded the development of the Benue trough and the final connection of the North and South Atlantic Oceans. The Cretaceous sediments, up to 3000 meters thick, represent lacustrine, fluvial, and alluvial fan deposits, and suggest an axiallydrained half-graben sedimentation model.
Archosaur fossils recovered from the eastern Koum basin include the teeth of two terrestrial crocodylians (cf. Araripesuchus wegeneri and cf. Sebecosuchia) teeth of sauropod and two kinds of theropod dinosaurs (cf. Spinosauridae and Theropoda indet.), and postcrania and teeth of the ornithopod dinosaur cf. Ouranosaurus nigeriensis. Archosaur trace fossils from the central Koum basin include the footprints of sauropod, two theropod, and an ornithopod dinosaur. The footprint assemblage is equivalent to the dinosaur osteological assemblage from the eastern basin in number and type of taxa represented.
The bone-bearing strata from the Koum basin are roughly correlative with the well-known Aptian Gadoufaoua fossil locality in Niger, based on the presence of Araripesuchus, cf. Spinosauridae, and Ouranosaurus; they are possibly younger than fossiliferous deposits from the Early cretaceous of Malawi that contain similar fauna! elements. Footprint-bearing strata from Koum are possibly correlative with pre-Gadoufaoua beds in Niger. Araripesuchus is known from South America and two other African localities; it enjoyed a broad distribution across western Gondwana prior to the isolation of Africa from South America. The presence of sebecosuchians in Koum demonstrates their early, wide dispersal. The range of spinosaurids in Africa is extended to the southwest, and the range of Ouranosaurus is extended southward by the Koum basin occurrences. The appearance of Ouranosaurus in African fossil localities may be the result of fauna! exchange with Laurasia in the Early cretaceous.
Degree Date
Summer 8-10-1990
Document Type
Thesis
Degree Name
M.S.
Advisor
Louis Jacobs
Number of Pages
245
Format
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Recommended Citation
Congleton, John DeForest Jr., "Vertebrate Paleontology Of The Koum Basin, Northern Cameroon, And Archosaurian Paleobiogeography In The Early Cretaceous" (1990). Earth Sciences Theses and Dissertations. 35.
https://scholar.smu.edu/hum_sci_earthsciences_etds/35
