Bahariya Formation

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Bahariya Formation
Stratigraphic range: Early Cenomanian[1]
~100–95 Ma
Spinosaurus with contemporaneous taxa.jpg
Restoration of some animals found
TypeGeological formation
UnderliesEl Heiz Fm., El Naqb Fm.[2]
OverliesBasement
Thickness≈100 m (330 ft)[2]
Lithology
PrimarySandstone
OtherMudstone, siltstone
Location
CoordinatesCoordinates: 28°24′20″N 28°48′20″E / 28.40556°N 28.80556°E / 28.40556; 28.80556
RegionWestern Desert
Country Egypt
Type section
Named forBahariya Oasis
Named bySaid 1962
Bahariya Formation is located in Egypt
Bahariya Formation
Bahariya Formation (Egypt)

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]

Extent[edit]

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[edit]

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[edit]

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

Vascular Plants of the Bahariya Formation
Genus Species Abundance Notes Images
Weichselia W. reticulata Dominant plant. Xerophytic tree fern suggestive of a dry tropical climate.
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[edit]

Foraminifera[edit]

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[edit]

Other microorganisms of the Bahariya Formation
Genus Species Images
Botryococcus
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[edit]

Molluscs[edit]

Molluscs of the Bahariya Formation
Genus Species Notes Images
Baculites A heteromorph ammonite with a nearly straight shell.
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[edit]

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[edit]

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

Vertebrates[edit]

Cartilaginous fish[edit]

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.
Modern Gymnura.


Modern Rhinoptera.


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[edit]

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.




Concavotectum C. moroccensis Possibly sinonymous 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 sinonymous 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[edit]

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

Squamates[edit]

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[edit]

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.

Crocodyliformes[edit]

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 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[edit]

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.
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[edit]

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.

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[edit]

Sources[edit]

References[edit]

  1. ^ a b c 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. ^ a b Catuneany et al., 2006, p.122
  3. ^ a b c d e f g h i j 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.CS1 maint: Uses editors parameter (link)
  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.