Dakhla Formation

Dakhla Formation
Stratigraphic range: Maastrichtian-Danian
~71–63 Ma
TypeGeological formation
Sub-units
  • Ammonite Hill Member
  • Baris Oyster Mudstone Member
  • Beida Shale Member
  • Kharga Shale Member
UnderliesTarawan Formation
OverliesDuwi Formation
Thickness230 meters
Lithology
PrimaryShale
OtherMarl, Phosphorite
Location
CountryEgypt

The Dakhla Formation, also called the Dakhla Shale, is a Maastrichtian-Danian geologic formation in the Western Desert, Egypt. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.

One of the younger Danian-aged localities of the formation, the Qreiya 3 site, is a lagerstätte preserving the earliest known records of numerous modern fish groups.

Fossil content

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.

Reptiles

Dinosaurs

Dinosaurs reported from the Dakhla Formation
GenusSpeciesPresence MaterialNotesImages
Sauropoda Ammonite Hill Member A left femur (Vb-646). Comparable to femurs of Brachiosaurus and Saltasaurus

Turtles

Turtles reported from the Dakhla Formation
GenusSpeciesPresence MaterialNotesImages
Arenila A. krebsi Ammonite Hill Member Partial skull A bothremydid turtle
?Cf. A. krebsi Ammonite Hill Member Partial dorsal shell and right pelvis A bothremydid turtle
Bothremydidae Undetermined large forms Ammonite Hill Member Nuchal bone, left pleuron, and partial plastron of one individual A large bothremydid turtle, with a shell length of 70–80 cm (28–31 in)
Gigantochelys G. aegyptiacus Beris Member Pelvic girdle A large dermochelyid turtle
Panchelonioidea Gen. et. sp. indet. Ammonite Hill Member Humerus (NVP010) A giant marine turtle
Taphrosphys T. cf. sulcatus Ammonite Hill Member Anterior part of dorsal shell and partial dorsal shell with partial anterior plastral lobe A bothremydid turtle
cf. T. sp. Ammonite Hill Member Left first pleural A bothremydid turtle
?aff. Tasbacka ?aff. T. sp. Ammonite Hill Member Left humerus A chelonioid sea turtle
Zolhafah Z. bella Ammonite Hill Member Skull A bothremydid turtle

Squamates

Squamates reported from the Dakhla Formation
GenusSpeciesPresence MaterialNotesImages
Globidens G. phosphaticus Beris Oyster Mudstone Member A single tooth crown (CUNV0011) A mosasaurine.
Halisaurus H. auriculatus Beris Oyster Mudstone Member A halisaurine
H. hebae
Mosasaurinae Indeterminate Beris Oyster Mudstone Member A fragmentary small dentary with a single tooth (CUNV0012) A mosasaurine
Palaeophiidae Indeterminate Qreiya 3 A marine snake.
Prognathodon P. sp. Lower part Two tooth crowns, three cervical, nine dorsal, three caudal vertebrae, and ribs, found in association (NVP025) Most similar to P. overtoni, possibly a member of that species

Cartilaginous fish

Fish reported from the Dakhla Formation
GenusSpeciesPresence MaterialNotesImages
Hexanchidae Qreiya 3 Teeth A cow shark.
Odontaspididae Qreiya 3 Teeth A sand shark.
Sclerorhynchus S. cf. leptodon Beris Member Four fragmentary rostral denticles originally attributed to Onchopristis sp. A sawskate
Sclerorhynchoidei Indeterminate Beris Member An exceptionally large, 1.46 metres (4.8 ft) long rostrum originally attributed to Onchopristis sp. A sawskate

Ray-finned fish

Fish reported from the Dakhla Formation
GenusSpeciesPresence MaterialNotesImages
Anomoeodus A. aegypticus Lower Beris Member A single specimen (NVP023) A pycnodont.
A. teneidaensis A single specimen (NVP024)
Aulostomoidea Indeterminate Qreiya 3 Articulated skeleton A trumpetfish and cornetfish relative.
Carangidae Indeterminate Qreiya 3 Articulated skeleton A relative of jacks.
Clupeoidei Indeterminate Qreiya 3 Articulated skeleton A herring relative.
Diastemapycnodus D. tavernensis Beris Member A single vomer with partial dentition A pycnodont
Mene sp. Qreiya 3 Articulated skeleton A moonfish.
cf. Nursallia Indeterminate Qreiya 3 Articulated skeleton A pycnodont.
Osteoglossidae Indeterminate Qreiya 3 Articulated skeleton A bonytongue.
Scombrinae (Eocoelopomini) Indeterminate Qreiya 3 Articulated skeleton A scombrid.
Syngnathidae Indeterminate Qreiya 3 Articulated skeleton A pipefish.
Veliferidae Indeterminate Qreiya 3 Articulated skeleton A sailfin velifer.
Trichiuroidea Indeterminate Qreiya 3 Articulated skeleton A relative of cutlassfish and snake mackerels.
Wadiichthys W. anbaawyi Beris Member A saurodontid ichthyodectiform
Zeiformes Indeterminate Qreiya 3 Articulated skeleton A zeiform.

Invertebrates

Bivalves

Bivalves reported from the Dakhla Formation
GenusSpeciesPresence MaterialNotesImages
Apectoichnus A. longissimus Ammonite Hill Member Borings in Nypa fruits Bivalve borings
Teredolites T. clavatus Ammonite Hill Member 32 moderately preserved borings (TBT02-33) and two badly preserved specimens (TBT44-45) in Nypa fruits Bivalve borings

Plants

Plants reported from the Dakhla Formation
GenusSpeciesPresence MaterialNotesImages
Nypa N. burtinii Fruits and seed casts A mangrove palm
N. sp. Ammonite Hill Member Fruits with bivalve borings A mangrove palm

See also

References

  1. 1 2 3 4 5 6 7 El Hedeny, M.; Kassab, W.; Rashwan, M.; Abu El-Kheir, G.; AbdelGawad, M. (2020-07-01). "Bivalve borings in Maastrichtian fossilNypafruits: Dakhla Formation, Bir Abu Minqar, South Western Desert, Egypt". Ichnos. 28 (1): 24–33. doi:10.1080/10420940.2020.1784158. ISSN 1042-0940. S2CID 225527064.
  2. 1 2 3 4 5 6 AbdelGawad, Mohamed K.; Abu El-Kheir, Gebely A.; Kassab, Walid G. (September 2021). "The youngest records of mosasaurid reptiles from the Upper Cretaceous of the South-Western Desert in Egypt". Proceedings of the Geologists' Association. 132 (5): 556–562. Bibcode:2021PrGA..132..556A. doi:10.1016/j.pgeola.2021.07.004. ISSN 0016-7878.
  3. ↑ "UPPER DAKHLA FORMATION ( BEIDA SHALE MEMBER) AT G. DUWI, RED SEA, EGYPT: MINERALOGICAL AND GEOCHEMICAL ASPECTS | Faculty of Science". www.aun.edu.eg. Retrieved 2022-11-23.
  4. 1 2 3 4 5 Anan, Tarek I.; Abd El-Wahed, Ahmed G. (2017-12-15). "The Maastrichtian-Danian Dakhla Formation, Eastern Desert, Egypt: Utilization in manufacturing lightweight aggregates". Applied Clay Science. 150: 10–15. Bibcode:2017ApCS..150...10A. doi:10.1016/j.clay.2017.08.027. ISSN 0169-1317.
  5. 1 2 El-Kheir, Gebely A. Abu; Shaker, Ahmed A.; Street, Hallie P.; Longrich, Nicholas R.; Strougo, Amin; Asan, Anhar; AbdelGawad, Mohamed (9 November 2023). "A Prognathodontin Mosasaur from the Maastrichtian of the Dakhla Oasis, Western Desert, Egypt". Fossil Studies. 1 (1): 60–75. doi:10.3390/fossils1010007. ISSN 2813-6284.
  6. ↑ Tantawy, A. A.; Keller, G.; Adatte, T.; Stinnesbeck, W.; Kassab, A.; Schulte, P. (2001-12-01). "Maastrichtian to Paleocene depositional environment of the Dakhla Formation, Western Desert, Egypt: sedimentology, mineralogy, and integrated micro- and macrofossil biostratigraphies". Cretaceous Research. 22 (6): 795–827. Bibcode:2001CrRes..22..795T. doi:10.1006/cres.2001.0291. ISSN 0195-6671.
  7. ↑ Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517–607.
  8. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 El-Sayed, Sanaa; Friedman, Matt; Salem, Belal S.; Gohar, Abdullah S.; Al-Ashqar, Shorouq F.; Amin, Mohamed; El-Saka, Hossam; Saad, Hadeel; Speijer, Robert P.; Sallam, Hesham M. (2026-06-05). "Rise of modern marine fishes captured in an early Paleocene Lagerstätte". Science Advances. 12 (23). doi:10.1126/sciadv.aec8978. ISSN 2375-2548. PMC 13232593. PMID 42234753.
  9. 1 2 3 Rauhut, Oliver W M; Werner, Christa (January 1997). "First record of a Maastrichtian sauropod dinosaur from Egypt". Palaeontolgia Africana. 34: 63–67.
  10. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 de Lapparent, France; Werner, Christa (April 1998). "New Late Cretaceous turtles from the Western Desert, Egypt". Annales de Paléontologie. 84 (2): 131–214. Bibcode:1998AnPal..84..131D. doi:10.1016/S0753-3969(98)80005-0.
  11. 1 2 3 Mousa, Mohamed K.; Tantawy, Abdel Aziz A.; Abu El-Kheir, Gebely A. (February 2026). "First known gigantic dermochelyid turtle (Pan-Chelonioidea) from the Upper Cretaceous deposits of Dakhla Oasis, Western Desert, Egypt". Cretaceous Research (in press) 106357. doi:10.1016/j.cretres.2026.106357.
  12. 1 2 Abu El-Kheir, G. A.-M.; AbdelGawad, M. K.; Kassab, W. G. (2021). "First known gigantic sea turtle from the Maastrichtian deposits in Egypt". Acta Palaeontologica Polonica. 66 (2): 349–355.
  13. ↑ Shaker, A. A.; Longrich, N. R.; Strougo, A.; Asan, A.; Bardet, N.; Mousa, M. K.; Tantawy, A. A.; Abu El-Kheir, G. A. (2023). "A new species of Halisaurus (Mosasauridae: Halisaurinae) from the lower Maastrichtian (Upper Cretaceous) of the Western Desert, Egypt". Cretaceous Research. 154. 105719. doi:10.1016/j.cretres.2023.105719.
  14. ↑ Shaker, A. A.; Longrich, N. R.; Strougo, A.; Asan, A.; Kamel Mousa, M.; Abu El-Kheir, G. A.-M. (2026). "A new species of halisaurine mosasaurid from the Upper Cretaceous of Egypt". Acta Palaeontologica Polonica. 71 (3): 589–604. doi:10.4202/app.01310.2025.
  15. 1 2 El-Sayed, S.; Friedman, M.; Salem, B. S.; Gohar, A. S.; Al-Ashqar, S. F.; Amin, M.; El-Saka, H.; Saad, H.; Speijer, R. P.; Sallam, H. M. (2026). "Rise of modern marine fishes captured in an early Paleocene Lagerstätte". Science Advances. 12 (23) eaec8978. doi:10.1126/sciadv.aec8978. PMC 13232593. PMID 42234753.
  16. 1 2 Greenfield, T. (2025). "No evidence for a giant, late-surviving Onchopristis: Comment on Capasso et al. (2024)". Journal of African Earth Sciences. 223. 105541. doi:10.1016/j.jafrearsci.2025.105541.
  17. 1 2 Capasso, L.; Abdel Aziz, S.; Tantawy, A. A.; Mousa, M. K.; Wahba, D. G. A.; Abu El-Kheir, G. A. (2024). "The first described Onchopristis Stromer, 1917, (Elasmobranchii: †Onchopristidae) from the Marine Maastrichtian of Dakhla Formation, Western Desert, Egypt". Journal of African Earth Sciences. 105415. doi:10.1016/j.jafrearsci.2024.105415.
  18. 1 2 Capasso, Luigi; Abu El-kheir, Gebely Abdelmaksoud; Mousa, Mohamed Kamel; Tantawy, Abdel Aziz (December 2021). "ANOMOEODUS AEGYPTICUS N. SP. (PISCES, †PYCNODONTIFORMES) FROM THE LATE CRETACEOUS OF THE DAKHLA FORMATION, WESTERN DESERT, EGYPT". Thalassia Salentina (43): 89–104.
  19. 1 2 Marzouk, A.; Capasso, L.; Zahran, E.; Kasem, A. M.; Kamel, A.; Kamel, M.; Abu El-Kheir, G. A. (2026). "New material of pycnodonts (Actinopterygii, † Pycnodontiformes) from the Maastrichtian deposits of Dakhla Basin, Western Desert, Egypt". Thalassia Salentina. 48: 35–50.
  20. 1 2 Abu El-Kheir; Tantawy; Mousa; Wahba; Capasso (2022-12-02). "Diastemapycnodus tavernensis gen. et sp. nov. (Actinopterygii, †Pycnodontiformes) from the marine Maastrichtian (Late Cretaceous) of the Dakhla Formation, Western Desert, Egypt". Historical Biology: A Journal of Paleobiology. 34 (12): 2324–2331. Bibcode:2022HBio...34.2324A. doi:10.1080/08912963.2021.2014482. S2CID 245051336.
  21. ↑ Abu El-Kheir, G. A.; Marzouk, A.; Capasso, L.; Zahran, E.; Kasem, A. M.; Kamel, A.; Mousa, M. K.; Elbsebeshi, A. (2026). "A new saurodontid fish from the Late Cretaceous of the Western Desert, Egypt". Acta Palaeontologica Polonica. 71 (1): 85–94. doi:10.4202/app.01277.2025.
  22. ↑ Abu El-Kheir, G. A.; Marzouk, A.; Capasso, L.; Zahran, E.; Kasem, A. M.; Kamel, A.; Mousa, M. K.; Elbsebeshi, A. (2026). "A new saurodontid fish from the Late Cretaceous of the Western Desert, Egypt". Acta Palaeontologica Polonica. 71 (1): 85–94. doi:10.4202/app.01277.2025.
  23. ↑ El-Soughier, Maher I.; Mehrotra, R.C.; Zhou, Zhi-Yan; Shi, Gong-Le (January 2011). "Nypa fruits and seeds from the Maastrichtian–Danian sediments of Bir Abu Minqar, South Western Desert, Egypt". Palaeoworld. 20 (1): 75–83. doi:10.1016/j.palwor.2010.09.016. ISSN 1871-174X.

Bibliography

  • Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.