Earth:Dakhla Formation

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Dakhla Formation
Stratigraphic range: Maastrichtian-Danian
~71–63 Ma
TypeGeological formation
Sub-units
  • Ammonite Hill Member[1]
  • Baris Oyster Mudstone Member[2]
  • Beida Shale Member[3]
  • Kharga Shale Member[2]
UnderliesTarawan Formation[4]
OverliesDuwi Formation[4]
Thickness230 meters[4]
Lithology
PrimaryShale[4]
OtherMarl, Phosphorite
Location
CountryEgypt

The Dakhla Formation, also called the Dakhla Shale,[5] is a Maastrichtian-Danian geologic formation in the Western Desert, Egypt.[4][6] Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.[7]

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.[8]

Fossil content

Template:Paleobiota-key-compact-stacked

Reptiles

Dinosaurs

Dinosaurs reported from the Dakhla Formation
Genus Species Presence Material Notes Images
Sauropoda Ammonite Hill Member[9] A left femur (Vb-646).[9] Comparable to femurs of Brachiosaurus and Saltasaurus[9]

Turtles

Turtles reported from the Dakhla Formation
Genus Species Presence Material Notes Images
Arenila A. krebsi Ammonite Hill Member[10] Partial skull[10] A bothremydid turtle
?Cf. A. krebsi Ammonite Hill Member[10] Partial dorsal shell and right pelvis[10] A bothremydid turtle
Bothremydidae Undetermined large forms Ammonite Hill Member[10] Nuchal bone, left pleuron, and partial plastron of one individual[10] A large bothremydid turtle, with a shell length of 70–80 cm (28–31 in)[10]
Gigantochelys G. aegyptiacus[11] Beris Member[11] Pelvic girdle[11] A large dermochelyid turtle
Panchelonioidea Gen. et. sp. indet. Ammonite Hill Member[12] Humerus (NVP010)[12] A giant marine turtle
Taphrosphys T. cf. sulcatus Ammonite Hill Member[10] Anterior part of dorsal shell and partial dorsal shell with partial anterior plastral lobe[10] A bothremydid turtle
cf. T. sp. Ammonite Hill Member[10] Left first pleural[10] A bothremydid turtle
?aff. Tasbacka ?aff. T. sp. Ammonite Hill Member[10] Left humerus[10] A chelonioid sea turtle
Zolhafah Z. bella Ammonite Hill Member[10] Skull[10] A bothremydid turtle

Squamates

Squamates reported from the Dakhla Formation
Genus Species Presence Material Notes Images
Globidens G. phosphaticus Beris Oyster Mudstone Member[2] A single tooth crown (CUNV0011)[2] A mosasaurine.
Halisaurus H. auriculatus Beris Oyster Mudstone Member[13][14] A halisaurine
H. hebae
Mosasaurinae Indeterminate Beris Oyster Mudstone Member[2] A fragmentary small dentary with a single tooth (CUNV0012)[2] A mosasaurine
Palaeophiidae Indeterminate Qreiya 3[8] A marine snake.
Prognathodon P. sp. Lower part Two tooth crowns, three cervical, nine dorsal, three caudal vertebrae, and ribs, found in association (NVP025)[5] Most similar to P. overtoni, possibly a member of that species

Cartilaginous fish

Fish reported from the Dakhla Formation[15]
Genus Species Presence Material Notes Images
Hexanchidae Qreiya 3[8] Teeth A cow shark.
Odontaspididae Qreiya 3[8] Teeth A sand shark.
Sclerorhynchus S. cf. leptodon[16] Beris Member Four fragmentary rostral denticles originally attributed to Onchopristis sp.[17] A sawskate
Sclerorhynchoidei Indeterminate[16] Beris Member An exceptionally large, 1.46 metres (4.8 ft) long rostrum originally attributed to Onchopristis sp.[17] A sawskate

Ray-finned fish

Fish reported from the Dakhla Formation[15]
Genus Species Presence Material Notes Images
Anomoeodus A. aegypticus[18] Lower Beris Member A single specimen (NVP023)[18] A pycnodont.
A. teneidaensis[19] A single specimen (NVP024)[19]
Aulostomoidea Indeterminate[8] Qreiya 3[8] Articulated skeleton A trumpetfish and cornetfish relative.
Carangidae Indeterminate[8] Qreiya 3[8] Articulated skeleton A relative of jacks.
Clupeoidei Indeterminate[8] Qreiya 3[8] Articulated skeleton A herring relative.
Diastemapycnodus D. tavernensis Beris Member[20] A single vomer with partial dentition[20] A pycnodont
Mene sp. Qreiya 3[8] Articulated skeleton A moonfish. frameless
cf. Nursallia Indeterminate[8] Qreiya 3[8] Articulated skeleton A pycnodont.
Osteoglossidae Indeterminate[8] Qreiya 3[8] Articulated skeleton A bonytongue.
Scombrinae (Eocoelopomini) Indeterminate[8] Qreiya 3[8] Articulated skeleton A scombrid.
Syngnathidae Indeterminate[8] Qreiya 3[8] Articulated skeleton A pipefish.
Veliferidae Indeterminate[8] Qreiya 3[8] Articulated skeleton A sailfin velifer.
Trichiuroidea Indeterminate[8] Qreiya 3[8] Articulated skeleton A relative of cutlassfish and snake mackerels.
Wadiichthys[21] W. anbaawyi Beris Member[22] A saurodontid ichthyodectiform
Zeiformes Indeterminate[8] Qreiya 3[8] Articulated skeleton A zeiform.

Invertebrates

Bivalves

Bivalves reported from the Dakhla Formation
Genus Species Presence Material Notes Images
Apectoichnus A. longissimus Ammonite Hill Member[1] Borings in Nypa fruits[1] Bivalve borings
Teredolites T. clavatus Ammonite Hill Member[1] 32 moderately preserved borings (TBT02-33) and two badly preserved specimens (TBT44-45) in Nypa fruits[1] Bivalve borings

Plants

Plants reported from the Dakhla Formation
Genus Species Presence Material Notes Images
Nypa N. burtinii Fruits and seed casts[23] A mangrove palm
N. sp. Ammonite Hill Member[1] Fruits with bivalve borings[1] A mangrove palm

See also

  • List of dinosaur-bearing rock formations
    • List of stratigraphic units with indeterminate dinosaur fossils

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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. https://www.researchgate.net/publication/339002137. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 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. doi:10.1016/j.pgeola.2021.07.004. ISSN 0016-7878. Bibcode: 2021PrGA..132..556A. https://www.researchgate.net/publication/354793174. 
  3. ↑ "UPPER DAKHLA FORMATION ( BEIDA SHALE MEMBER) AT G. DUWI, RED SEA, EGYPT: MINERALOGICAL AND GEOCHEMICAL ASPECTS | Faculty of Science". https://www.aun.edu.eg/science/upper-dakhla-formation-beida-shale-member-g-duwi-red-sea-egypt-mineralogical-and-geochemical. 
  4. ↑ 4.0 4.1 4.2 4.3 4.4 Anan, Tarek I.; Abd El-Wahed, Ahmed G. (2017-12-15). "The Maastrichtian-Danian Dakhla Formation, Eastern Desert, Egypt: Utilization in manufacturing lightweight aggregates" (in en). Applied Clay Science 150: 10–15. doi:10.1016/j.clay.2017.08.027. ISSN 0169-1317. Bibcode: 2017ApCS..150...10A. https://www.sciencedirect.com/science/article/pii/S0169131717303782. 
  5. ↑ 5.0 5.1 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" (in en). 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. doi:10.1006/cres.2001.0291. ISSN 0195-6671. Bibcode: 2001CrRes..22..795T. https://www.sciencedirect.com/science/article/pii/S0195667101902915. 
  7. ↑ Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517–607.
  8. ↑ 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 8.11 8.12 8.13 8.14 8.15 8.16 8.17 8.18 8.19 8.20 8.21 8.22 8.23 8.24 El-Sayed, Sanaa; Friedman, Matt; Salem, Belal S.; Gohar, Abdullah S.; Al-Ashqar, Shorouq F.; Amin, Mohamed; El-Saka, Hossam; Saad, Hadeel et al. (2026-06-05). "Rise of modern marine fishes captured in an early Paleocene Lagerstätte" (in en). Science Advances 12 (23). doi:10.1126/sciadv.aec8978. ISSN 2375-2548. PMID 42234753. PMC 13232593. https://www.science.org/doi/10.1126/sciadv.aec8978. 
  9. ↑ 9.0 9.1 9.2 Rauhut, Oliver W M; Werner, Christa (January 1997). "First record of a Maastrichtian sauropod dinosaur from Egypt". Palaeontolgia Africana 34: 63–67. https://www.researchgate.net/publication/235907515. 
  10. ↑ 10.00 10.01 10.02 10.03 10.04 10.05 10.06 10.07 10.08 10.09 10.10 10.11 10.12 10.13 10.14 de Lapparent, France; Werner, Christa (April 1998). "New Late Cretaceous turtles from the Western Desert, Egypt". Annales de Paléontologie 84 (2): 131–214. doi:10.1016/S0753-3969(98)80005-0. Bibcode: 1998AnPal..84..131D. https://www.researchgate.net/publication/240435581. 
  11. ↑ 11.0 11.1 11.2 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." (in en). Cretaceous Research (in press). doi:10.1016/j.cretres.2026.106357. 
  12. ↑ 12.0 12.1 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. https://www.app.pan.pl/article/item/app008492020.html. 
  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. https://app.pan.pl/article/item/app013102025.html. 
  15. ↑ 15.0 15.1 El-Sayed, S.; Friedman, M.; Salem, B. S.; Gohar, A. S.; Al-Ashqar, S. F.; Amin, M.; El-Saka, H.; Saad, H. et al. (2026). "Rise of modern marine fishes captured in an early Paleocene Lagerstätte". Science Advances 12 (23). doi:10.1126/sciadv.aec8978. PMID 42234753. 
  16. ↑ 16.0 16.1 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. ↑ 17.0 17.1 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. ↑ 18.0 18.1 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. https://www.researchgate.net/publication/357930651. 
  19. ↑ 19.0 19.1 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. https://ese-journals.unisalento.it/index.php/thalassiasal/article/view/33102. 
  20. ↑ 20.0 20.1 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. doi:10.1080/08912963.2021.2014482. Bibcode: 2022HBio...34.2324A. https://www.ingentaconnect.com/content/tandf/ghbi/2022/00000034/00000012/art00007. 
  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. https://www.researchgate.net/publication/251707921. 

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.