Bahariasaurus

Last updated

Bahariasaurus
Temporal range: Late Cretaceous, 95  Ma
O
S
D
C
P
T
J
K
Pg
N
Bahariasaurus vertebra.png
Vertebra of Bahariasaurus from specimen 1912 VIII 62
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Bahariasauridae
Genus: Bahariasaurus
Stromer, 1934
Species:
B. ingens
Binomial name
Bahariasaurus ingens
Stromer, 1934
Synonyms

Bahariasaurus is an enigmatic genus of large theropod dinosaur. The genus is known to have included at least 1 species, Bahariasaurus ingens (meaning "huge Bahariya lizard"), which was found in North African rock layers dating to the Cenomanian and Turonian ages of the Late Cretaceous. The only fossils confidently assigned to Bahariasaurus were found in the Bahariya Formation of the Bahariya (Arabic: الواحة البحرية meaning the "northern oasis") oasis in Egypt by Ernst Stromer but were destroyed during a World War II bombing raid with the same raid taking out the holotype of Spinosaurus and Aegyptosaurus among other animals found in the Bahariya Formation. While there have been more fossils assigned to the genus such as some from the Farak Formation of Niger, these remains are referred to with much less certainty. [1] Bahariasaurus is, by most estimations, one of the largest theropods, approaching the height and length of other large bodied theropods such as Tyrannosaurus rex and the contemporaneous Carcharodontosaurus . The aforementioned estimations tend to put it at around 11–12.2 metres (36–40 ft) in length and 4-4.8 tonnes in overall weight. [2] [3] [4]

Contents

History

Bahariasaurus was found during the 1910s during an expedition to Egypt's Baharija Formation led by Markgraf and Stromer, and the holotype, specimen 1912 VIII 62, was discovered in 1911. [5] The type species, B. ingens, was described by Ernst Stromer in 1934. [6] It was considered to be potentially the largest known theropod. This specimen was destroyed in an air raid during World War II on the night of 23/24 April 1944.

The questionable remains of Bahariasaurus from the Farak Formation of Niger, which consist of a proximal caudal centrum (65 mm), two mid caudal centra and three mid caudal centra (from different individuals) were discovered some time later during the 20th century and described by de Lapparent in 1960. [1] [7] It is possible that these remains may have belonged to another unrelated theropod.

Description

Bahariasaurus was a notably large theropod. The type species, B. ingens, is only known from post-cranial material. The two centra of the posterior dorsal vertebrae are ~157% and 189% longer than they are tall, and ~82% and ~95% wider than they are tall. [1] All preserved sacrals have a longitudinally elongate pleurocoel and a ventral median groove, which is unknown in any ceratosaurs. The last sacral vertebrae known from Bahariasaurus implies that there was no greater fusion of the vertebrae after that. [6] The 22.5 cm long vertebra of Bahariasaurus 1912 VIII 62 is the longest dorsal vertebra among all theropods, 12.5% longer than that of Sue. [4]

Classification

The exact taxonomic placement of Bahariasaurus is uncertain, although it has been variously assigned to several theropod groups, including the Carcharodontosauridae [8] and the superfamily Tyrannosauroidea. [9] The smaller contemporaneous theropod Deltadromeus 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. [2] More specimens would be needed to more accurately classify it and determine its relationship to Deltadromeus.

However, the taxon has posterior dorsal and sacral pleurocoels, a proximally placed interpubic fenestra and ventrally-grooved sacrals, which makes the taxon unlikely to be a ceratosaur. [10]

If added to the phylogenetic analysis of Carrano (2012), it is recovered as an indeterminate tetanuran.

In the 2016 description and analysis of the megaraptoran Aoniraptor , Bahariasaurus was found, along with Gualicho , Aoniraptor and Deltadromeus to probably form a family in the still poorly understood clade known as the Megaraptora and are different from the more derived megaraptorids. [11]

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. [12]

However, Cau (2024) included the Bahariasaurus type specimen in a phylogenetic analysis and recovered it in a monophyletic clade near the base of Ceratosauria along with Aoniraptor , Deltadromeus , and Gualicho , with Elaphrosaurus as the sister taxon to this clade. [13]

Paleobiology

Restoration of Bahariasaurus as a noasaur (far right background) with contemporaneous animals of the Bahariya Formation Bahariya Formation McAfee.jpg
Restoration of Bahariasaurus as a noasaur (far right background) with contemporaneous animals of the Bahariya Formation

Bahariasaurus was one of four giant theropods known from the Bahariya Formation, the other three being the allosauroid Carcharodontosaurus and the spinosaurids Spinosaurus and Sigilmassasaurus , 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 exhibited niche-partitioning in order to avoid competition so that they could coexist in the same environment. [14]

Related Research Articles

<i>Spinosaurus</i> Genus of spinosaurid dinosaur

Spinosaurus is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian stage of the Late Cretaceous period, about 100 to 94 million years ago. The genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material came to light in the early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The type species is S. aegyptiacus from Egypt and Morocco. Although a potential second dubious species, S. maroccanus, has been recovered from Morocco, this dubious species is likely a junior synonym of S. aegyptiacus. Other possible junior synonyms include Sigilmassasaurus from the Kem Kem beds in Morocco and Oxalaia from the Alcântara Formation in Brazil, though other researchers propose both genera to be distinct taxa.

<i>Carcharodontosaurus</i> Genus of carcharodontosaurid dinosaur from the Cretaceous period

Carcharodontosaurus is a genus of carnivorous theropod dinosaur that lived in North Africa from about 100 to 94 million years ago during the Cenomanian age of the Late Cretaceous. Two teeth of the genus, now lost, were first described from Algeria by French paleontologists Charles Depéret and Justin Savornin as Megalosaurus saharicus. A partial skeleton was collected by crews of German paleontologist Ernst Stromer during a 1914 expedition to Egypt. Stromer did not report the Egyptian find until 1931, in which he dubbed the novel genus Carcharodontosaurus, making the type species C. saharicus. Unfortunately, this skeleton was destroyed during the Second World War. In 1995 a nearly complete skull of C. saharicus, the first well-preserved specimen to be found in almost a century, was discovered in the Kem Kem Beds of Morocco; it was designated the neotype in 1996. Fossils unearthed from the Echkar Formation of northern Niger were described and named as another species, C. iguidensis, in 2007.

<span class="mw-page-title-main">Ernst Stromer</span> German paleontologist

Ernst Freiherr Stromer von Reichenbach was a German paleontologist best remembered for his expedition to Egypt, during which the discovery of the first known remains of Spinosaurus was made.

<span class="mw-page-title-main">Spinosauridae</span> Family of dinosaurs

Spinosauridae is a clade or family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. Spinosaurid fossils have been recovered worldwide, including Africa, Europe, South America and Asia. Their remains have generally been attributed to the Early to Mid Cretaceous.

<i>Aegyptosaurus</i> Titanosaurid sauropod dinosaur genus from late Cretaceous Period

Aegyptosaurus is a genus of sauropod dinosaur that lived in what is now Africa, around 95 million years ago, during the Late Cretaceous Period.

<span class="mw-page-title-main">Carcharodontosauridae</span> Extinct family of dinosaurs

Carcharodontosauridae is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae as a family, which, in modern paleontology, indicates a clade within Carnosauria. Carcharodontosaurids include some of the largest land predators ever known: Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan all rivaled Tyrannosaurus in size. Estimates give a maximum weight of 8–10 metric tons for the largest carcharodontosaurids, while the smallest carcharodontosaurids were estimated to have weighed at least 500 kilograms (1,100 lb).

<i>Deltadromeus</i> Theropod dinosaur genus from mid-Cretaceous Period

Deltadromeus is a genus of theropod dinosaur from the Aoufous Formation of Morocco.

<i>Elaphrosaurus</i> Ceratosaurian theropod dinosaur genus from the Late Jurassic Period

Elaphrosaurus is a genus of ceratosaurian theropod dinosaur that lived approximately 154 to 150 million years ago during the Late Jurassic Period in what is now Tanzania in Africa. Elaphrosaurus was a medium-sized but lightly built member of the group that could grow up to 6.2 m (20 ft) long. Morphologically, this dinosaur is significant in two ways. Firstly, it has a relatively long body but is very shallow-chested for a theropod of its size. Secondly, it has very short hindlimbs in comparison with its body. Phylogenetic analyses indicate that this genus is likely a ceratosaur. Earlier suggestions that it is a late surviving coelophysoid have been examined but generally dismissed. Elaphrosaurus is currently believed to be a very close relative of Limusaurus, an unusual beaked ceratosaurian which may have been either herbivorous or omnivorous.

Inosaurus is the name given to a dubious genus of theropod dinosaur from the Early Cretaceous-aged "Continental intercalaire" and Early Cretaceous (Albian)-aged Echkar Formation of Niger and possibly from the Late Cretaceous (Cenomanian)-aged Baharija Formation of Egypt The type, and only species, is Inosaurus tedreftensis.

<i>Sigilmassasaurus</i> Spinosaurid theropod dinosaur genus from Cretaceous Period

Sigilmassasaurus is a 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 Canadian paleontologist Dale Russell, it contains a single species, Sigilmassasaurus brevicollis. The identity of the genus has been debated by scientists, with some considering its fossils to represent material from the closely related species Spinosaurus aegyptiacus, while others have classified it as a separate taxon, forming the clade Spinosaurini with Spinosaurus as its sister taxon.

The Farak Formation is a geological formation in Niger, central Africa.

Bahariasauridae is a potential family of averostran theropods that might include a handful of African and South American genera, such as Aoniraptor, Bahariasaurus, Deltadromeus, and Gualicho. The placement of these theropods is controversial, with some studies placing them as basal ceratosaurs possibly related to Noasauridae, others classifying them as megaraptorans, basal neovenatorids, or basal coelurosaurs. There is also a possibility the group might not be monophyletic, as a monograph on the vertebrate diversity in the Kem Kem Beds published in 2020 found Bahariasaurus to be nomen dubium. In the same paper Deltadromeus is classified as an noasaurid, a result also recovered by some previous studies. A 2024 phylogenetic analysis found Aoniraptor, Bahariasaurus, Deltadromeus, and Gualicho to form a monophyletic clade as the sister taxon to Elaphrosaurus near the base of Ceratosauria.

Kemkemia is a genus of probable crocodyliforms living in the Cretaceous, described from a single fossil that was recovered in 1999 from Morocco by an Italian team searching for fossil invertebrates. The fossil of Kemkemia dates from the Cenomanian age.

<span class="mw-page-title-main">Megaraptora</span> Extinct clade of dinosaurs

Megaraptora is a clade of carnivorous theropod dinosaurs with controversial relationships to other tetanuran theropods. Its derived members, the Megaraptoridae are noted for their large hand claws and powerfully-built forelimbs, which are usually reduced in size in other large theropods.

<i>Oxalaia</i> Extinct genus of dinosaurs

Oxalaia is a genus of spinosaurid dinosaur that lived in what is now the Northeast Region of Brazil during the Cenomanian stage of the Late Cretaceous period, sometime between 100.5 and 93.9 million years ago. Its only known fossils were found in 1999 on Cajual Island in the rocks of the Alcântara Formation, which is known for its abundance of fragmentary, isolated fossil specimens. The remains of Oxalaia were described in 2011 by Brazilian palaeontologist Alexander Kellner and colleagues, who assigned the specimens to a new genus containing one species, Oxalaia quilombensis. The species name refers to the Brazilian quilombo settlements. Oxalaia quilombensis is the eighth officially named theropod species from Brazil and the largest carnivorous dinosaur discovered there. One study suggested that this taxon is a junior synonym of the closely related African genus Spinosaurus, but this was disputed by subsequent studies which consider the genus to be diagnostic.

<i>Paralititan</i> Genus of a titanosaurian sauropod dinosaur

Paralititan was a giant titanosaurian sauropod dinosaur genus discovered in coastal deposits in the Upper Cretaceous Bahariya Formation of Egypt. It lived between 99.6 and 93.5 million years ago.

<i>Ichthyovenator</i> Genus of dinosaur

Ichthyovenator is a genus of spinosaurid dinosaur that lived in what is now Laos, sometime between 120 and 113 million years ago, during the Aptian stage of the Early Cretaceous period. It is known from fossils collected from the Grès supérieurs Formation of the Savannakhet Basin, the first of which were found in 2010, consisting of a partial skeleton without the skull or limbs. This specimen became the holotype of the new genus and species Ichthyovenator laosensis, and was described by palaeontologist Ronan Allain and colleagues in 2012. The generic name, meaning "fish hunter", refers to its assumed piscivorous lifestyle, while the specific name alludes to the country of Laos. In 2014, it was announced that more remains from the dig site had been recovered; these fossils included teeth, more vertebrae (backbones) and a pubic bone from the same individual.

Aoniraptor is a genus of possibly megaraptoran or bahariasaurid theropod dinosaur from the Late Cretaceous of Argentina.

Gualicho 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 supercontinent Gondwana. The fossils were found in the Huincul Formation, dating to the late Cenomanian-early Turonian age of the upper Cretaceous Period, around 91 million years ago.

<i>Tratayenia</i> Extinct genus of dinosaurs

Tratayenia is an extinct genus of megaraptoran theropod dinosaurs known from remains found in the Santonian-age Bajo de la Carpa Formation of Argentina. The type and only species, Tratayenia rosalesi, was described in March 2018.

References

  1. 1 2 3 "Megalosauroidea". www.theropoddatabase.com. Retrieved 10 December 2020.
  2. 1 2 Holtz, Thomas R. Jr. (2008) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages Supplementary Information
  3. Paul, Gregory S. (2016). The Princeton Field Guide to Dinosaurs. Princeton University Press. p. 81. ISBN   978-1-78684-190-2. OCLC   985402380.
  4. 1 2 Molina-Pérez, Rubén; Larramendi, Asier; Connolly, David; Cruz, Gonzalo Ángel Ramírez (25 June 2019). Dinosaur Facts and Figures. Princeton University Press. ISBN   978-0-691-18031-1.
  5. Josh., Smith (2013). The lost dinosaurs of egypt. Random House. ISBN   978-1-58836-117-2. OCLC   869562622.
  6. 1 2 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.
  7. de Lapparent A. F. (1960) "The dinosaurs of the “Continental Intercalaire” of the central Sahara". Memoirs of the Geological Society of France39: 1-60.
  8. Rauhut, (1995). "Zur systematischen Stellung der afrikanischen Theropoden Carcharodontosaurus Stromer 1931 und Bahariasaurus Stromer 1934." Berliner geowissenschaftliche Abhandlungen, E16 (Gundolf-Ernst-Festschrift): 357-375.
  9. 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.
  10. Mortimer, Mickey (17 September 2014). "The Theropod Database Blog: No giant Egyptian Deltadromeus". The Theropod Database Blog. Retrieved 3 December 2023.
  11. Matías J. Motta; Alexis M. Aranciaga Rolando; Sebastián Rozadilla; Federico E. Agnolín; Nicolás R. Chimento; Federico Brissón Egli & Fernando E. Novas (2016). "New theropod fauna from the Upper Cretaceous (Huincul Formation) of northwestern Patagonia, Argentina". New Mexico Museum of Natural History and Science Bulletin. 71: 231–253.
  12. Ibrahim, Nizar; Sereno, Paul C.; Varricchio, David J.; Martill, David M.; Dutheil, Didier B.; Unwin, David M.; Baidder, Lahssen; Larsson, Hans C.E.; Zouhri, Samir; Kaoukaya, Abdelhadi (21 April 2020). "Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco". ZooKeys (928): 1–216. doi: 10.3897/zookeys.928.47517 . ISSN   1313-2989. PMC   7188693 . PMID   32362741.
  13. Cau, Andrea (2024). "A Unified Framework for Predatory Dinosaur Macroevolution" (PDF). Bollettino della Società Paleontologica Italiana. 63 (1): 1–19. doi:10.4435/BSPI.2024.08 (inactive 20 November 2024). ISSN   0375-7633.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
  14. Farlow Pianka, James, Eric (2002). "Body Size Overlap, Habitat Partitioning and Living Space Requirements of Terrestrial Vertebrate Predators: Implications for the Paleoecology of Large Theropod Dinosaurs". Historical Biology. 16: 21–40. doi:10.1080/0891296031000154687. S2CID   18114585.{{cite journal}}: CS1 maint: multiple names: authors list (link)