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 | |||||||
|---|---|---|---|---|---|---|---|
| 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 | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Sauropoda | Ammonite Hill Member[8] | A left femur (Vb-646).[8] | Comparable to femurs of Brachiosaurus and 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 and right pelvis[9] | A bothremydid turtle | ||
| Bothremydidae | Undetermined large forms | Ammonite Hill Member[9] | Nuchal bone, left pleuron, and partial plastron of one individual[9] | A large bothremydid turtle, with a shell length of 70–80 cm (28–31 in)[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 and 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[13] | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Anomoeodus | A. aegypticus[14] | Lower Beris Member | A single specimen (NVP023)[14] | A pycnodont. | |
| A. teneidaensis[15] | A single specimen (NVP024)[15] | ||||
| Diastemapycnodus | D. tavernensis | Beris Member[16] | A single vomer with partial dentition[16] | A pycnodont | |
| Sclerorhynchus | S. cf. leptodon[17] | Beris Member | Four fragmentary rostral denticles originally attributed to Onchopristis sp.[18] | A sawskate | |
| Sclerorhynchoidei | Indeterminate[17] | Beris Member | An exceptionally large, 1.46 metres (4.8 ft) long rostrum originally attributed to Onchopristis sp.[18] | A sawskate | |
| Wadiichthys[19] | W. anbaawyi | Beris Member[20] | A saurodontid ichthyodectiform | ||
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[21] | A mangrove palm | ||
| N. sp. | Ammonite Hill Member[1] | Fruits with bivalve borings[1] | A mangrove palm | ||
