Dakhla Formation Explained

Dakhla Formation
Type:	Geological formation
Age:	Maastrichtian-Danian ~
Period:	Cretaceous
Prilithology:	Shale
Otherlithology:	Marl, Phosphorite
Country:	Egypt
Subunits:	Ammonite Hill Member Baris Oyster Mudstone Member Beida Shale Member^[1] Kharga Shale Member
Underlies:	Tarawan Formation
Overlies:	Duwi Formation
Thickness:	230 meters

The Dakhla Formation, also called the Dakhla Shale,^[2] is a Maastrichtian-Danian geologic formation in the Western Desert, Egypt.^{[3] [4]} Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.^[5]

Fossil content

Reptiles

Turtles

Turtles reported from the Dakhla Formation
Genus	Species	Presence	Material	Notes	Images
Arenila	A. krebsi	Ammonite Hill Member	Partial skull.	A bothremydid turtle.
	?Cf. A. krebsi	Ammonite Hill Member	Partial dorsal shell & right pelvis.	A bothremydid turtle.
Bothremydidae	Undetermined large forms	Ammonite Hill Member^[7]	Nuchal bone, left pleuron & partial plastron of one individual.	A large bothremydid turtle, with a shell length of 70 to 80 centimeters.
Panchelonioidea	Gen. et. sp. indet.	Ammonite Hill Member^[8]	Humerus (NVP010).	A giant marine turtle.
Taphrosphys	T. cf. sulcatus	Ammonite Hill Member	Anterior part of dorsal shell & 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.

Mosasaurs

Mosasaurs reported from the Dakhla Formation
Genus	Species	Presence	Material	Notes	Images
Globidens	G. phosphaticus	Beris Oyster Mudstone Member^[9]	A single tooth crown (CUNV0011).	A mosasaurine.
Mosasaurinae	Indeterminate	Beris Oyster Mudstone Member	A fragmentary small dentary with a single tooth (CUNV0012).	A mosasaurine.
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

Fish

Fish reported from the Dakhla Formation
Genus	Species	Presence	Material	Notes	Images
Anomoeodus	A. aegypticus	Lower Beris Member^[10]	A single specimen (NVP023).	A pycnodont.
Diastemapycnodus	D. tavernensis	Beris Member^[11]	"A single vomer with partial dentition".	A pycnodont.

Invertebrates

Bivalves

Bivalves reported from the Dakhla Formation
Genus	Species	Presence	Material	Notes	Images
Apectoichnus	A. longissimus	Ammonite Hill Member^[12]	Borings in Nypa fruits.	Bivalve borings.
Teredolites	T. clavatus	Ammonite Hill Member	32 moderately preserved borings (TBT02-33) & two badly preserved specimens (TBT44-45) in Nypa fruits.	Bivalve borings.

Plants

Plants reported from the Dakhla Formation
Genus	Species	Presence	Material	Notes	Images
Nypa	N. burtinii		Fruits & seed casts.^[13]	A mangrove palm
	N. sp.	Ammonite Hill Member	Fruits with bivalve borings.	A mangrove palm.

See also

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

References

Bibliography

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

Notes and References

1. Web site: UPPER DAKHLA FORMATION (BEIDA SHALE MEMBER) AT G. DUWI, RED SEA, EGYPT: MINERALOGICAL AND GEOCHEMICAL ASPECTS Faculty of Science . 2022-11-23 . www.aun.edu.eg.
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 . en . 1 . 1 . 60–75 . 10.3390/fossils1010007 . free . 2813-6284.
3. 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 . en . 150 . 10–15 . 10.1016/j.clay.2017.08.027 . 2017ApCS..150...10A . 0169-1317.
4. 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 . 10.1006/cres.2001.0291 . 2001CrRes..22..795T . 0195-6671.
5. Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517–607.
6. Rauhut . Oliver W M . Werner . Christa . January 1997 . First record of a Maastrichtian sauropod dinosaur from Egypt . Palaeontolgia Africana . 34 . 63–67.
7. de Lapparent . France . Werner . Christa . April 1998 . New Late Cretaceous turtles from the Western Desert, Egypt . Annales de Paléontologie . 84 . 2 . 131–214. 10.1016/S0753-3969(98)80005-0 . 1998AnPal..84..131D .
8. 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.
9. 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 . 10.1016/j.pgeola.2021.07.004 . 2021PrGA..132..556A . 0016-7878.
10. 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.
11. 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 . 10.1080/08912963.2021.2014482. 2022HBio...34.2324A . 245051336 .
12. 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 . 10.1080/10420940.2020.1784158 . 225527064 . 1042-0940.
13. 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 . 10.1016/j.palwor.2010.09.016 . 1871-174X.