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Bahariasaurus

Stromer, 1934 bah-hah-REE-ya-SAWR-us

From Bahariya (the Bahariya Oasis and Formation in Egypt, where the fossils were found) + Greek sauros (σαῦρος) meaning 'lizard'; overall meaning 'Bahariya lizard'.

100.5–93.9 million years ago Cenomanian, Late Cretaceous
Late Cretaceous stages

Bahariasaurus is an enigmatic genus of large theropod dinosaur. The genus contains a single species, Bahariasaurus ingens, which was found in North African rock layers dating to the Cenomanian age of the Late Cretaceous. The only fossils confidently assigned to Bahariasaurus were found in the Bahariya Formation of the Bahariya Oasis in Egypt by Ernst Stromer. This material was destroyed during a World War II bombing raid, with the same raid also destroying the holotypes of Spinosaurus, Aegyptosaurus, and other animals found in the Bahariya Formation.

Under dispute

Bahariasaurus ingens is a large theropod whose holotype was destroyed in 1944, complicating its classification. It has historically been allied with tetanurans (as a carcharodontosaurid or megaraptoran), but recent phylogenetic analyses recover it within Ceratosauria as an abelisauroid (Cau, 2024; Cau and Paterna, 2025). Cau and Paterna (2025) further argue that Deltadromeus agilis is a junior synonym of Bahariasaurus; that synonymy is not yet widely adopted. It is placed at Abelisauroidea incertae sedis following the prevailing recent view.

Diagnosis

  1. Posterior dorsal vertebrae platycoelous, strongly elongate (nearly twice as long as high anteriorly), diaphysis constricted with lateral oval foramen indicating internal hollowness, diapophysis broad supported only by posterior strut, no parapophysis
  2. Sacrum of 3 vertebrae with platycoelous elongate bodies, each with a lateral foramen and a broad longitudinal ventral groove
  3. Pubic foot extremely small and almost lacking an anterior part, shaft forms U-shape with contralateral bone, very long symphysis with thin connecting lamella ending above the foot
  4. Ilium with remarkably straight upper margin, postacetabular part tapering to an acute posterior angle, ischial process very short
  5. Femur shaft slender and convexly curved forward; trochanter IV only a strong longitudinal ridge positioned above mid-shaft; medial condyle below flatter and less deeply projecting than the strongly arched outer condyle
  6. Scapula shaft of approximately constant width to the very top (not expanded distally), contrasting with all known theropods; coracoid triangular without posterior median corner, with foramen near the joint

Species

Bahariasaurus ingens Stromer, 1934

Type species

From Latin 'ingens' meaning 'huge', referring to the enormous size of the animal.

Holotype
BSP 1922 X 47 , Bayerische Staatssammlung für Paläontologie und Geologie
Material
Group of gypsum-preserved bones: sacrum of 3 fused vertebral bodies, posterior dorsal and cervical vertebrae, ossa pubis, ischium, and rib fragments.
Horizon
Bahariya Formation, Cenomanian, Late Cretaceous , 100.5–93.9 million years ago
Locality
Jabal Ghurābī, Giza, Egypt

References

  1. Stromer, E. (1934). Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltierreste der Baharîje-Stufe (unterstes Cenoman). 13. Dinosauria [Results of the expeditions of Professor E. Stromer in the Egyptian deserts. II. Vertebrate animal remains from the Baharîje bed (lowest Cenomanian). 13. Dinosauria]. Abhandlungen der Bayerischen Akademie der Wissenschaften Mathematisch-naturwissenschaftliche Abteilung, Neue Folge 22: 1-79. stromer1934a
  2. Cau, A. (2024). A Unified Framework for Predatory Dinosaur Macroevolution. Bollettino della Società Paleontologica Italiana 63(1): 1-19. doi:10.4435/BSPI.2024.08

    Recovered Bahariasaurus within Ceratosauria as an abelisauroid.

    cau2024a
  3. Cau, A.; Paterna, A. (2025). Beyond the Stromer's Riddle: the impact of lumping and splitting hypotheses on the systematics of the giant predatory dinosaurs from northern Africa. Italian Journal of Geosciences 144(2): 162-185. doi:10.3301/IJG.2025.10

    Argued Deltadromeus agilis is a junior synonym of Bahariasaurus.

    cau2025a
  4. Carrano, M. T.; Sampson, S. D. (2008). The Phylogeny of Ceratosauria (Dinosauria: Theropoda). Journal of Systematic Palaeontology 6(2): 183-236. doi:10.1017/S1477201907002246

    Discussed Bahariasaurus only in comparison with Deltadromeus agilis; left its position unresolved (comparison only, not a scored analysis result).

    carrano2008a