Dakhla Formation
Geological formation in Egypt
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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]
| Dakhla Formation | |
|---|---|
| Stratigraphic range: Maastrichtian-Danian ~ | |
| Type | Geological formation |
| Sub-units | |
| Underlies | Tarawan Formation[4] |
| Overlies | Duwi Formation[4] |
| Thickness | 230 meters[4] |
| Lithology | |
| Primary | Shale[4] |
| Other | Marl, Phosphorite |
| Location | |
| Country | Egypt |
Fossil content
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Reptiles
Dinosaurs
| Dinosaurs reported from the Dakhla Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Sauropoda | Ammonite Hill Member[8] | A left femur (Vb-646).[8] | Most similar to femurs of Brachiosaurus or Saltasaurus.[8] | ||
Turtles
| Turtles reported from the Dakhla Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Arenila | A. krebsi | Ammonite Hill Member[9] | Partial skull.[9] | A bothremydid turtle. | |
| ?Cf. A. krebsi | Ammonite Hill Member[9] | Partial dorsal shell & right pelvis.[9] | A bothremydid turtle. | ||
| Bothremydidae | Undetermined large forms | Ammonite Hill Member[9] | Nuchal bone, left pleuron & partial plastron of one individual.[9] | A large bothremydid turtle, with a shell length of 70 to 80 centimeters.[9] | |
| Gigantochelys | G. aegyptiacus[10] | Beris Member[10] | Pelvic girdle[10] | A large dermochelyid turtle | |
| Panchelonioidea | Gen. et. sp. indet. | Ammonite Hill Member[11] | Humerus (NVP010).[11] | A giant marine turtle. | |
| Taphrosphys | T. cf. sulcatus | Ammonite Hill Member[9] | Anterior part of dorsal shell & partial dorsal shell with partial anterior plastral lobe.[9] | A bothremydid turtle. | |
| Cf. T. sp. | Ammonite Hill Member[9] | Left first pleural.[9] | A bothremydid turtle. | ||
| ?Aff. Tasbacka | ?Aff. T. sp. | Ammonite Hill Member[9] | Left humerus.[9] | A chelonioid sea turtle. |  |
| Zolhafah | Z. bella | Ammonite Hill Member[9] | Skull.[9] | A bothremydid turtle. | |
Mosasaurs
| Mosasaurs 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. hebae | Beris Oyster Mudstone Member[12] | A halisaurine | ||
| Mosasaurinae | Indeterminate | Beris Oyster Mudstone Member[2] | A fragmentary small dentary with a single tooth (CUNV0012).[2] | A mosasaurine. | |
| 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 | |
Fish
| Fish reported from the Dakhla Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Anomoeodus | A. aegypticus | Lower Beris Member[13] | A single specimen (NVP023).[13] | A pycnodont. | |
| Diastemapycnodus | D. tavernensis | Beris Member[14] | "A single vomer with partial dentition".[14] | A pycnodont. | |
| Sclerorhynchus | S. cf. leptodon[15] | Beris Member | Four fragmentary rostral denticles originally attributed to Onchopristis sp.[16] | A sawskate. | |
| cf. Otodus | cf. O. obliquus[citation needed] | Fragmentary teeth and possible vertebra founds. | A otodontid. | ||
| Sclerorhynchoidei | Indeterminate[15] | Beris Member | An exceptionally large, 1.46 metres (4.8 ft) long rostrum originally attributed to Onchopristis sp.[16] | A sawskate. | |
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) & 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 & seed casts.[17] | A mangrove palm | ||
| N. sp. | Ammonite Hill Member[1] | Fruits with bivalve borings.[1] | A mangrove palm. | ||
