Bahariya Formation

The Bahariya Formation (also transcribed as Baharija Formation) is a fossiliferous geologic formation dating back to the early Cenomanian, which outcrops within the Bahariya depression in Egypt, and is known from oil exploration drilling across much of the Western Desert where it forms an important oil reservoir.[1][3][4]

Bahariya Formation Stratigraphic range: Early Cenomanian[1] ~100–95 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Restoration of some animals found
Type	Geological formation
Underlies	El Heiz Fm., El Naqb Fm.[2]
Overlies	Basement
Thickness	≈100 m (330 ft)[2]
Lithology
Primary	Sandstone
Other	Mudstone, siltstone
Location
Coordinates
Region	Western Desert
Country	Egypt
Type section
Named for	Bahariya Oasis
Named by	Said
Year defined	1962
Bahariya Formation (Egypt)

Extent

The Bahariya Formation forms the base of the depression, the lower part of the enclosing escarpment and all of the small hills within.[5] The type section for the formation is found at Gebel El-Dist, a hill at the northern end of the Bahariya depression.[6]

Stratigraphy and sedimentology

Four depositional sequences have been recognised in the Bahariya Formation in the Bahariya depression, separated by three sub-aerial unconformities. The formation was deposited during a period of relative rise in sea level, with each unconformity representing a relative fall in sea level.[1] Each of the individual sequences contains sediments deposited under fluvial, shoreline and shallow marine conditions.

Flora

Thirty different genera are known from Bahariya, including megaflora. Much of the material is yet to be described.[7]

Vascular Plants
Genus	Species	Abundance	Notes	Images
Weichselia	W. reticulata	Dominant plant.	Xerophytic tree fern suggestive of a dry tropical climate.	Cladophlebis
Agathis			An Araucarian conifer, now restricted to Australasia.
Cladophlebis			A water fern.
Liriodendrites
Marsilea			Water fern.
Nelumbites

Other taxa include Sapindales, Piperaceae, Lauraceae, Platanaceae, Magnoliopsida, Nymphaeaceae, Cornaceae, Proteaceae and Vitaceae not identified at genus level; and miospore and pollen species.

Microfauna and Meiofauna

Foraminifera

Foraminifera of the Bahariya Formation
Genus	Species
Charentia	C. cuvillieri
Flavusella	F. washitensis
Mayncina	M. orbignyi
Rotalipora	R. cushmani R. reicheli
Thomasinella	T. aegyptia T. fragmentaria T. punica
Whiteinella	W. archaeocretacea

Other microorganisms

Other microorganisms of the Bahariya Formation
Genus	Species	Images
Botryococcus		Botryococcus Pediastrum Scenedesmus
Coronifera	C. oceanica
Cyclonephelium	C. edwardsii C. vannophorum
Dynopterigium	D. cladoides
Exochosphaeridium
Florentinia	F. cooksoniae F. mantlii
Kallosphaeridium
Mudrongia	M. simplex
Palaeoperidinium	P. cretaceum
Pediastrum
Pseudoceratium	P. anaphrisum P. securigerum
Scenedesmus
Spiniferites
Subtilisphaera	S. perlucida S. senegalensis
Xiphophoridium	X. alatum

Invertebrates

Molluscs

Molluscs of the Bahariya Formation
Genus	Species	Notes	Images
Baculites		A heteromorph ammonite with a nearly straight shell.	Baculites.
Cardium		A cockle.
Exogyra		A reef-forming true oyster associated with solid substrates and warm temperatures.
Gastrochaena		A saltwater clam.
Neolobites	N. vibrayeanus	A typical rolled ammonite.
Nucula		A small saltwater clam.
Ostrea	O. flabeata	An edible oyster.

Crustaceans

Crustaceans of the Bahariya Formation
Genus	Species	Notes	Images
Amphicytherura	A. sexta
Anticythereis	A. gaensis
Bairdia	B. bassiounii B. elongata
Brachycythere	B. ledaforma porosa
Bythoceratina	B. avnonensis B. tamarae
Bythocypris	B. eskeri
Cythereis	C. algeriana C. bicornis levis C. canteriolata
Cytherella	C. ovata C. paenovata C. parallela C. sulcata
Fabanella
Looneyella	L. sohni
Loxoconcha	L. clinocosta L. fletcheri
Metacytheropteron	M. berbericum
Ovocytheridea	O. caudata O. producta O. reniformis
Paracypris	P. acutocaudata P. angusta P. mdaouerensis P. triangularis
Pterigocythere	P. raabi
Veeniacythereis	V. jezzineensis
Xestoleberis	X. obesa

Insects

Direct fossils are sparse, though plant leaves with extensive damage from folivorous insects have been documented.

Vertebrates

Cartilaginous fish

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Chondrichthyes of the Bahariya Formation
Genus	Species	Abundance	Notes	Images
Aegyptobatus	A. kuehnei		A sclerorhynchiform.	Cretolamna. Modern Gymnura. Onchopristis tooth. Modern Rhinoptera. Scapanorhynchus Squalicorax Modern Squatina.
Asteracanthus	A. aegyptiacus		A hybodont shark.
Baharipristis	B. bastetiae		A sclerorhynchiform.
Cretodus	C. longiplicatus		A shark.
Cretolamna	C. appendiculata		A mackerel shark.
Distobatus	D. nutiae		A sclerorhynchiform.
Gymnura	G. laterialata		A butterfly ray.
Haimirichia	H. amonensis		A shark previously classified in the genera Odontaspis, Serratolamna, and Carcharias.
Isidobatus	I. tricarinatus		A sclerorhynchiform.
Marckgrafia	M. lybica		A sclerorhynchiform.
Onchopristis	O. numidus	One complete cranium and associated vertebrae.	A giant sclerorhynchid sawfish.
Peyeria	P. libyca		A sclerorhynchiform.
Ptychotrygon	P. henkeli		A sclerorhynchiform.
Renpetia	R. labiicarinata		A sclerorhynchiform.
Rhinoptera			A batoid ray.
Schizorhiza	S. stromeri		An unusual sclerorhynchid sawfish that retained its rostral teeth after they were replaced.
Squalicorax	S. baharijensis		A large shark.
Scapanorhynchus	S. subulatus		A mitsukurinid similar to the modern goblin shark.
Squatina			An angelshark.
Tribodus	T. aschersoni		A hybodont.

Bony fish

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Osteichthyes of the Bahariya Formation
Genus	Species	Abundance	Notes	Images
Bawitius	B. bartheli		A giant bichir.	Ceratodus Enchodus Lepidotes Mawsonia Neoceratodus Saurodon
Concavotectum	C. moroccensis		Possibly synonymous with Paranogmius doederleini.
Ceratodus			A lungfish.
Coelodus			A pycnodontid.
Enchodus		One tooth.	A predatory fish.
Lepidotes		Isolated scales.	Possibly misidentified from Bawitius bartheli.
Mawsonia	M. lybica	Considered a "signature taxon" of the formation.	A giant freshwater coelacanth. Species assignation deemed provisional due to the lack of neotype.
Neoceratodus	N. africanus		A lungfish related to the living Australian species.
Palaeonotopterus	P. greenwoodi		Nomen conservandum of the two Plethodus species previously described.
Paranogmius	Paranogmius doederleini	One vertebra.	Holotype lost in World War II. Could be synonymous with Concavotectum moroccensis.
Plethodus	P. libycus P. tibniensis		Holotypes destroyed in World War II, but now believed to have been misidentified Palaeonotopterus greenwoodi.
Retodus	R. tuberculatus		A lungfish species identified from remains previously assigned to Neoceratodus.
Saurodon			Identified by Stromer in 1936, but now rejected due to this genus appearing only in post-Cenomanian Europe and North America. Now listed as Ichthyodectidae incertae sedis.
Stromerichthys	S. aethiopicus		A predatory bowfin relative.

Testudines

Testudines of the Bahariya Formation
Genus	Species	Abundance	Notes	Images
Apertotemporalis	A. baharijensis		A small sea turtle. Other unnamed species are also present.

Squamates

Squamates of the Bahariya Formation
Genus	Species	Abundance	Notes	Images
Simoliophys		Abundant	First known sea snake, with functional hind legs. Now believed to include elements from different species and at least one of a different, unnamed genus.

Plesiosaurs

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Plesiosaurs of the Bahariya Formation
Genus	Species	Abundance	Notes	Images
Leptocleidus	L. capensis		A small plesiosaur that visited brackish or fresh water systems. Though known from both South Africa and England, the Egyptian material lacks diagnostic traits of the genus and is now referred as Polycotylidae incertae sedis.	Leptocleidus

Crocodyliformes

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Crocodyliformes of the Bahariya Formation
Genus	Species	Abundance	Notes	Images
Aegyptosuchus	A. peyeri		A poorly known, possibly stomatosuchid crocodile.	Hamadasuchus Stomatosuchus
Hamadasuchus	H. rebouli		A terrestrial, dog-like peirosaurid. It is possible that some material previously attributed to Libycosuchus actually belongs to this species.
Libycosuchus	L. brevirostris		A terrestrial crocodile of uncertain affinities, possibly related to Notosuchus.
Stomatosuchus	S. inermis	A complete cranium	A large, flat-headed stomatosuchid with multiple small conical teeth, and possibly a pelican-like throat pouch. The only remains were destroyed in World War II.
Stromerosuchus	S. aegyptiacus	Fragmentary remains	Nomen dubium assigned to material found in 1911, that were badly damaged in 1922 while being shipped to Germany for study. Some material may belong to Aegyptosuchus and other to Stomatosuchus.

Sauropods

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Sauropods of the Bahariya Formation
Genus	Species	Material	Notes	Images
Aegyptosaurus[3]	A. baharijensis[3]	Partial postcranial skeleton[8]	A titanosaur of about 15 meters. All remains were destroyed in World War II.	Paralititan
Dicraeosaurus	D. hansemanni	Isolated scapula and vertebra	Identified by Stromer in 1932. Subsequently considered a rebbachisaurid, or a third, unnamed titanosaur.
Paralititan[3]	P. stromeri[3]	Partial postcranial skeleton[9]	One of the largest titanosaurs of the Cretaceous, with a 1.69 meters long humerus and an estimated total length of 26 meters.

Theropods

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Theropods of the Bahariya Formation
Genus	Species	Abundance	Notes	Images
Bahariasaurus	B. ingens[3]		A medium-sized theropod of uncertain affinities. Possibly a megaraptoran, a relative of Deltadromeus, or both.	Bahariasaurus Carcharodontosaurus Spinosaurus
Carcharodontosaurus[3]	C. saharicus[3]		A large carcharodontosaurid allosauroid.
Elaphrosaurus			Material now considered to be indeterminate theropod remains.[3]
Sigilmassasaurus[3]	S. brevicollis		Previously considered a species of Spinosaurus, or a synonym of S. aegyptiacus.
Spinosaurus	S. aegyptiacus	Most common dinosaur of the formation.	A large spinosaurid.

In addition, there are isolated teeth disputedly assigned to dromaeosaurids, or to abelisaurids.

See also

• List of dinosaur-bearing rock formations

References

1. Catuneanu O., Khalifa M.A. & Wanas H.A. (2006). "Sequence stratigraphy of the Lower Cenomanian Bahariya Formation, Bahariya Oasis, Western Desert, Egypt" (PDF). Sedimentary Geology. 190 (1–4): 121–137. doi:10.1016/j.sedgeo.2006.05.010.
2. Catuneany et al., 2006, p.122
3. Weishampel, David B; et al (2004). "Dinosaur distribution (Late Cretaceous, Africa)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 604. ISBN 0-520-24209-2.
4. Macgregor D.S. & Moody R.T.G. (1998). "Mesozoic and Cenozoic petroleum systems of North Africa". In Macgregor D.S.; Moody R.T.G.; Clark-Lowes D.D. (eds.). Petroleum geology of North Africa. Special Publications. 132. Geological Society. pp. 201–216. ISBN 9781862390041.
5. Khalifa M.A. & Catuneanu O. (2008). "Sedimentology of the fluvial and fluvio-marine facies of the Bahariya Formation (Early Cenomanian), Bahariya Oasis, Western Desert, Egypt". Journal of African Earth Sciences. 51 (2): 89–103. doi:10.1016/j.jafrearsci.2007.12.004.
6. Tanner L.H. & Khalifa M.A. (2010). "Origin of ferricretes in fluvial-marine deposits of the Lower Cenomanian Bahariya Formation, Bahariya Oasis, Western Desert, Egypt". Journal of African Earth Sciences. 56 (4–5): 179–189. doi:10.1016/j.jafrearsci.2009.07.004.
7. Ijouhier, Jamale (2016) A reconstruction of the palaeoecology and environmental dynamics of the Bahariya Formation of Egypt. PeerJ Preprints, https://doi.org/10.7287/peerj.preprints.2470v1
8. "Table 13.1," in Weishampel, et al. (2004). Page 267.
9. "Table 13.1," in Weishampel, et al. (2004). Page 269.