Bahariya El-Wahat el-Bahariya or el-Bahariya ( ar, الواحات البحرية "''El-Wāḥāt El-Baḥrīya''", "the Northern Oases"); is a depression and a naturally rich oasis in the Western Desert of Egypt. It is approximately 370 km away from ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

theropod dinosaur Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally ...

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 ...

Bahariya El-Wahat el-Bahariya or el-Bahariya ( ar, الواحات البحرية "''El-Wāḥāt El-Baḥrīya''", "the Northern Oases"); is a depression and a naturally rich oasis in the Western Desert of Egypt. It is approximately 370 km away from ...

Arabic Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walter ...

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

Spinosaurus ''Spinosaurus'' (; ) is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian stages of the Late Cretaceous period, about 99 to 93.5 million years ago. The genus was known first f ...

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 ...

Farak Formation The Farak Formation is a geological formation in Niger, central Africa. Its strata date back to the Early Cenomanian. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosau ...

Niger ) , official_languages = , languages_type = National languages ''Bahariasaurus'' is, by most estimations, one of the largest theropods, approaching the size of other large bodied theropods such as ''Tyrannosaurus rex'' and the contemporaneous ''

Carcharodontosaurus ''Carcharodontosaurus'' (; ) is a genus of large carcharodontosaurid theropod dinosaur that existed during the Cenomanian age of the Late Cretaceous in Northern Africa. The genus ''Carcharodontosaurus'' is named after the shark genus '' Carc ...

''. The aforementioned estimations tend to put it at around 11–12 metres (36–39 ft) in length and 4 tonnes in overall weight.

History

''Bahariasaurus'' was found during the 1910s during an expedition to

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...

's

Baharija 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 m ...

led by

Markgraf Margrave was originally the medieval title for the military commander assigned to maintain the defence of one of the border provinces of the Holy Roman Empire or of a kingdom. That position became hereditary in certain feudal families in the Em ...

and Stromer, and the holotype was discovered in 1911. The type species, ''B. ingens'', was described by Ernst Stromer in 1934. This specimen was destroyed in an air raid during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

on the night of 23/24 April 1944. The questionable remains of ''Bahariasaurus'' from the

Farak Formation The Farak Formation is a geological formation in Niger, central Africa. Its strata date back to the Early Cenomanian. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosau ...

of

Niger ) , official_languages = , languages_type = National languagesde Lapparent in 1960. It is possible that these remains may have belonged to another unrelated theropod.

Description

''Bahariasaurus'' was quite a large theropod. The type species, ''B. ingens'', is only known from post-cranial material. The two

centra Centra is a convenience shop chain that operates throughout Ireland. The chain operates as a symbol group owned by Musgrave Group, the food wholesaler, meaning the stores are all owned by individual franchisees. The chain has three different ...

of the posterior

dorsal vertebrae In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical ...

are ~157% and 189% longer than they are tall, and ~82% and ~95% wider than they are tall. All preserved sacrals have a longitudinally elongate

pleurocoel Skeletal pneumaticity is the presence of air spaces within bones. It is generally produced during development by excavation of bone by pneumatic diverticula (air sacs) from an air-filled space, such as the lungs or nasal cavity. Pneumatization is h ...

and a ventral median groove. The last sacral vertebrae known from ''Bahariasaurus'' implies that there was no greater fusion of the vertebrae after that.Stromer, E. (1934). "Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltier-Reste der Baharije-Stufe (unterstes Cenoman)." 13. Dinosauria. Abhandlungen der Bayerischen Akademie der Wissenschaften, Mathematisch-naturwissenschaftliche Abteilung n.f., 22: 1–79.

Classification

The exact taxonomic placement of ''Bahariasaurus'' is uncertain, although it has been variously assigned to several theropod groups, including the

Carcharodontosauridae Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, ''carcharodontósauros'': "shark-toothed lizards") is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae ...

Rauhut, (1995). "Zur systematischen Stellung der afrikanischen Theropoden ''Carcharodontosaurus'' Stromer 1931 und ''Bahariasaurus'' Stromer 1934." ''Berliner geowissenschaftliche Abhandlungen'', E16 (Gundolf-Ernst-Festschrift): 357-375. and the superfamily

Tyrannosauroidea Tyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinen ...

.Chure, (2000). "A new species of ''Allosaurus'' from the Morrison Formation of Dinosaur National Monument (Utah-Colorado) and a revision of the theropod family Allosauridae." Ph.D. dissertation, Columbia University, 1-964. The smaller contemporaneous theropod ''

Deltadromeus ''Deltadromeus'' (meaning "delta runner") is a genus of theropod dinosaur from Northern Africa. It had long, unusually slender hind limbs for its size, suggesting that it was a swift runner. The skull is not known. One fossil specimen of a sin ...

'' could potentially be synonymous with ''Bahariasaurus''. If this assumption is correct, ''Bahariasaurus'' would possibly represent the largest ceratosaur as recent studies consider ''Deltadromeus'' a ceratosaur, specifically a noasaurid.Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages'
Supplementary Information
/ref> More specimens (especially the skull) would be needed to more accurately classify it and determine its relationship to ''Deltadromeus''. In the 2016 description and analysis of the megaraptoran ''

Aoniraptor ''Aoniraptor'' is a megaraptoran theropod from the Late Cretaceous of Argentina (Huincul Formation). Discovery and naming The holotype, MPCA-Pv 804/1 to 804/25, which consists of the last sacral vertebra, six proximal caudal vertebrae, four mid ...

'', ''Bahariasaurus'' was found, along with ''

Gualicho ''Gualicho'' (named in reference to the gualichu) is a genus of theropod dinosaur. The type species is ''Gualicho shinyae''. It lived in what is now northern Patagonia, on what was then a South American island continent split off from the superco ...

'', ''Aoniraptor'' and ''

Deltadromeus ''Deltadromeus'' (meaning "delta runner") is a genus of theropod dinosaur from Northern Africa. It had long, unusually slender hind limbs for its size, suggesting that it was a swift runner. The skull is not known. One fossil specimen of a sin ...

'' to probably form a family in the still poorly understood clade known as the

Megaraptora Megaraptora is a clade of carnivorous Tetanurae, tetanuran theropod dinosaurs with controversial relations to other theropods. Its Derived (phylogenetics), derived members, the Megaraptoridae are noted for their elongated hand claws and proporti ...

and are different from the more derived megaraptorids. In 2016, Gregory S. Paul suggested that ''Deltadromeus'' may be a juvenile specimen of ''Bahariasaurus'', but that their relationship is uncertain and to be determined. A 2020 study found that a referred fossil of ''Bahariasaurus'' belongs to ''Deltadromeus,'' leaving ''Bahariasaurus'' to be regarded as a '' nomen dubium'' by the authors.

Paleobiology

''Bahariasaurus'' was one of four giant theropods known from the

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 ...

, the other three being the allosauroid ''

Carcharodontosaurus ''Carcharodontosaurus'' (; ) is a genus of large carcharodontosaurid theropod dinosaur that existed during the Cenomanian age of the Late Cretaceous in Northern Africa. The genus ''Carcharodontosaurus'' is named after the shark genus '' Carc ...

'' and the spinosaurids ''

Spinosaurus ''Spinosaurus'' (; ) is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian stages of the Late Cretaceous period, about 99 to 93.5 million years ago. The genus was known first f ...

'' and ''

Sigilmassasaurus ''Sigilmassasaurus'' ( ; "Sijilmassa lizard") is an extremely controversial genus of spinosaurid dinosaur that lived approximately 100 to 94 million years ago during the Late Cretaceous Period in what is now northern Africa. Named in 1996 by Ca ...

'', though the validity of ''Sigilmassasaurus'' is currently being debated as it may be a junior synonym of ''Spinosaurus''. It is likely the predators in the

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 ...

exhibited niche-partitioning in order to avoid competition so that they could coexist in the same environment.

References

{{Taxonbar, from=Q133070 Megaraptorans Late Cretaceous dinosaurs of Africa Cenomanian life Fossils of Egypt Cretaceous Niger Fossils of Niger Fossil taxa described in 1934 Taxa named by Ernst Stromer Nomina dubia