Bahariya Formation
Fossiliferous beds in North Africa
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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] ~ | |
Restoration of the environment and animals of the formation | |
| Type | Geological formation |
| Underlies | El Heiz Fm., El Naqb Fm.[2] |
| Overlies | Basement[2] |
| Thickness | ≈100 m (330 ft)[2] |
| Lithology | |
| Primary | Sandstone |
| Other | Mudstone, siltstone |
| Location | |
| Coordinates | 28°24′20″N 28°48′20″E |
| 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.
Microfauna and Meiofauna
Foraminifera
| Foraminifera of the Bahariya Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | |||||
| Charentia | C. cuvillieri | |||||
| Favusella | 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 |    | |||||
| 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. |  | ||||
| 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 (Ostracoda)
| 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 |
|||||
| Pterygocythere | 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
|
Notes Uncertain or tentative taxa are in small text; |
| Chondrichthyes of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Abundance | Notes | Images |
| Aegyptobatus | A. kuehnei | A sclerorhynchiform. |       | |
| 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. numida | One complete cranium and associated vertebrae. | A sclerorhynchid rajoid. | |
| Peyeria | P. libyca | A sclerorhynchiform. | ||
| Ptychotrygon | P. henkeli | A sclerorhynchiform. | ||
| Renpetia | R. labiicarinata | A sclerorhynchiform. | ||
| Rhinoptera | A batoid ray. | |||
| Scapanorhynchus | S. subulatus | A mitsukurinid similar to the modern goblin shark. | ||
| Schizorhiza | S. stromeri | Specimens are actually from the younger Ain Giffara Formation. | ||
| Squalicorax | S. baharijensis | Abundant. | A large shark. | |
| Squatina | An angelshark. | |||
| Tribodus | T. aschersoni | A hybodont. | ||
Bony fish
| Osteichthyes of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Abundance | Notes | Images |
| Bawitius | B. bartheli | A skull fragment, teeth, and several scales. | A giant bichir. |        |
| 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. | ||
| Obaichthys | O. africanus | An obaichthyid lepisosteiform. Remains formerly attributed to "Stromerichthys".[7] | ||
| Palaeonotopterus | P. greenwoodi | Nomen conservandum of the two Plethodus species previously described. | ||
| Paranogmius | P. doederleini | Two incomplete skulls and several vertebrae. | All definitive specimens were destroyed in World War II, however Concavotectum from the Kem Kem Beds of Morocco may be a synonym. | |
| 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 | Skull, jaw, and opercular bones. | A fish initially identified as a bowfin relative, but now thought to be a chimera consisting of remains assignable to Bawitius, Obaichthys, and others.[8] | |
Testudines
| Testudines of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Abundance | Notes | Images |
| Apertotemporalis[9] | A. baharijensis | An incomplete skull[9] | A small bothremydid pleurodiran turtle. Now classified as a nomen dubium indeterminate beyond Bothremydidae.[10] |  |
| cf. Araripemydidae[11] | Indeterminate | |||
| cf. Bothremydidae[11] | Indeterminate | |||
| cf. Chelonioidea[11] | Indeterminate | |||
Squamates
| Squamates of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Abundance | Notes | Images |
| Simoliophis | 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
| Plesiosaurs of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Abundance | Notes | Images |
| Leptocleidus | L. capensis[12] | Fragmentary skull bones, teeth, and vertebrae.[12] | Formerly assigned to Leptocleidus capensis, a species known from the UK and South Africa.[12][13] Now considered an indeterminate polycotylid.[14] |  |
Crocodyliformes
| Crocodyliformes of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Abundance | Notes | Images |
| Aegyptosuchus | A. peyeri | An incomplete skull. | A poorly known, possibly stomatosuchid crocodile. |   .jpg)  |
| 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 partial skull and two vertebrae. | 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. | |
Pterosaurs
| Pterosaurs of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Material | Notes | Images |
| Ornithocheiriformes indet.[15][16] | Indeterminate | Left first wing phalanx | A medium-sized pterosaur. The first record of a pterosaur from Egypt. | |
Dinosaurs
Sauropods
| Sauropods of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Material | Notes | Images |
| Aegyptosaurus[3] | A. baharijensis[3] | Three caudal vertebrae, a scapula, and several limb bones.[17] | A small/medium sized titanosaurid. Due to the remains being destroyed and fragmentary, little is known about the taxon.[18] |   |
| Dicraeosaurus | D. sp.[19] | An isolated caudal vertebra.[19] | Identified as Dicraeosaurus by Stromer in 1932.[18][19] Subsequently considered a rebbachisaurid, or a third, unnamed titanosaur.[20] | |
| Paralititan[3] | P. stromeri[3] | Four vertebrae, a scapula, and incomplete forelimb. An incomplete dorsal vertebra destroyed during WWII may also belong to P. stromeri.[20] | A large titanosaurid. | |
| Rebbachisauridae? indet. | Unnamed | An isolated scapula. | ||
Theropods
| Theropods of the Bahariya Formation | ||||
|---|---|---|---|---|
| Genus | Species | Abundance | Notes | Images |
| Abelisauridae indet.[21] | Unnamed | MUVP 477, an isolated caudal (tenth) cervical vertebra. | A medium-sized abelisaurid, estimated around 5.77 metres (18.9 ft) long.[21] |    |
| Abelisauridae? indet.[22] | Undescribed | Several shed teeth crowns.[22] | A small-sized theropod, possibly an abelisaurid. Additionally, its teeth superficially resemble those of dromaeosaurids but likely come from a different kind of theropod.[22] | |
| Bahariasaurus | B. ingens[3] | A holotype specimen consisting of an incomplete postcranial skeleton. Several other specimens have been assigned including femora, vertebrae, and scapulae.[23] | A large-sized theropod known from several fragmentary skeletons, all of which are now lost. The affinities of this genus are unknown, though it may be a megaraptoran,[24] ornithomimosaur,[25] ceratosaur, or other form of theropod.[26] Deltadromeus may be a synonym of Bahariasaurus,[26][27] though this is unclear.[25][28] | |
| Carcharodontosaurus[23] | C. saharicus | A partial skull, teeth, and fragmentary postcranial remains.[29] | Reassigned to own genus and species, Tameryraptor.[29] | |
| Ceratosauria? | ||||
| Deltadromeus | D. agilis | Several limb, pelvic, and pectoral girdle bones.[30] | Several remains originally referred to Bahariasaurus were referred to Deltadromeus.[30][31] It is uncertain whether it and Bahariasaurus are synonymous or distinct. | |
| cf. Elaphrosaurus | cf. E. bambergi | Two tibiae and a femur.[23] | Identified as cf. E. bambergi by Stromer in 1934.[23] Now regarded as coming from a tetanuran, possibly a coelurosaur,[32] or "probable ceratosaur".[21] | |
| aff. Erectopus | aff. E. sauvagei | An incomplete right tibia.[33] | May have affinities with Ceratosauria[21] or belong to Bahariasaurus[26] or Deltadromeus.[30] | |
| Spinosaurus[23] | "Spinosaurus B" | One individual known from a fragmentary postcranial skeleton.[23] | Considered a distinct species of Spinosaurus by Ernst Stromer.[23] It may instead belong to S. aegyptiacus,[34] Sigilmassasaurus brevicollis,[35] or its own species.[36] | |
| Spinosaurus | S. aegyptiacus | One associated skeleton consisting of skull and postcranial bones.[37] Fragmentary vertebrae, teeth, and other elements have also been found.[23][19] | A large spinosaurid. | |
| Tameryraptor[29] | T. markgrafi | A partial skull, teeth, and fragmentary postcranial remains.[29] | A large carcharodontosaurid theropod, originally assigned to Carcharodontosaurus.[29] | |
Flora
Thirty different genera are known from Bahariya, including megaflora. Much of the material is yet to be described.[38][39] Other taxa include Sapindales, Piperaceae, Lauraceae, Platanaceae, Magnoliopsida, Nymphaeaceae, Cornaceae, Proteaceae and Vitaceae not identified at genus level; and miospore and pollen species.[40][41]
| Vascular Plants | ||||
|---|---|---|---|---|
| Genus | Species | Abundance | Notes | Images |
| Agathis[42] | A/W spp. | Few Specimens | An Araucarian conifer, now restricted to Australasia. |
   |
| Agathoxylon[43] | A. (Dadoxylon) aegyptiacum | Wood | Araucarian woods | |
| Araliaephyllum?[38][40] | Indeterminate ("Morphotype-14") | Few Specimens | Suggested to be related with Lauraceae | |
| Cladophlebis[38][40] | C. spp. | Few Specimens | Fern Laflets | |
| Cornophyllum[38][40] | C. distense | Few Specimens | Suggested to be related with Cornaceae | |
| Cinnamophyllum?[38][40] | Indeterminate ("Morphotype-12") | Few Specimens | Suggested to be related with Lauraceae | |
| Eucalyptolaurus/"Myrtophyllum"(?)[40][41] | Indeterminate ("Morphotype-08") | Few Specimens | Specimens of the family Lauraceae | |
| Evodioxylon[43] | E. intermedium | Wood | Putative Rutaceae | |
| Laurophyllum[38][40] | L. africanum | Few Specimens | Specimens of the family Lauraceae | |
| Liriophyllum[38][40] | L. farafraense | Few Specimens | Specimens of the family Magnoliaceae | |
| Marsilea[42] | aff. Marsilea spp. | Few Specimens | Water fern. | |
| Magnoliid[40][41] |
|
Few Specimens | Shows festooned brochidodromous venation | |
| Magnoliaephyllum[40] |
|
Few Specimens | Possible affinities with Lauraceae | |
| Monocotyledon[44] | "Morphotype 26" | Few Specimens | Flowering Plant | |
| Nelumbites[40][41] |
|
Common occurrence in the lower shale bed | Typical leaves of the faimily Nelumbonaceae | |
| Nymphaeales[44] | Indeterminate ("Morphotype-22") | Few Specimens | Aquatic Flowering Plant | |
| Paradoxopteris[38][40] | P. stromeri | Co-Dominant plant | Xerophytic tree fern suggestive of a dry tropical climate. | |
| Plumafolium?[40][41] | Indeterminate ("Morphotype-18") | Few Specimens | A Monocot, probably related with Liliopsida | |
| Podozamites?[44] | Indeterminate ("Morphotype-27") | Few Specimens | Coniferophyte | |
| Pteridophyte[44] | Indeterminate ("Morphotype-28") | Few Specimens | Fern clearly distinct from Weichselia | |
| Rodgersia[38][40] | R. longifolia | Few Specimens | Likely lobes of a much bigger leaf of Sapindopsis type | |
| Trochodendroides?[44] | Indeterminate ("Morphotype-23") | Few Specimens | Probably related to Cercidiphyllaceae | |
| Typhaephyllum[38][40] | cf. T. sp. | Few Specimens | Interpreted as a monocot, probably related to Typhaceae | |
| Vitiphyllum[38][40] | V. aff. multifidum | Few Specimens | Some similarities with Pabiania of the family Lauraceae | |
| Weichselia[38] | W. reticulata | Dominant plant | Xerophytic tree fern suggestive of a dry tropical climate. | |