Tahora Formation
| Tahora Formation | |
|---|---|
| Stratigraphic range: Santonian-Maastrichtian (Piripauan) ~ | |
| Type | Geological formation |
| Unit of | Tinui Group |
| Sub-units | Maungataniwha Sandstone Member, Mutuera Member, Houpapa Member |
| Underlies | Whangai Formation |
| Overlies | Urewera Group or Matawai Group |
| Thickness | ~500 m (1,600 ft)[1] |
| Lithology | |
| Primary | Sandstone, conglomerate |
| Other | Siltstone |
| Location | |
| Coordinates | Lua error in Module:Coordinates at line 489: attempt to index field 'wikibase' (a nil value). |
| Approximate paleocoordinates | Lua error: callParserFunction: function "#coordinates" was not found. |
| Region | North Island |
| Country | New Zealand |
| Extent | Gisborne |
| Type section | |
| Named for | Tahora Station |
Tahora Formation (New Zealand) | |
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The Tahora Formation is a Late Cretaceous geologic formation that outcrops in northeastern New Zealand near Napier.[2][3] It is Haumurian in age according to the New Zealand geologic time scale (mainly Campanian, but ranging from Santonian to lower Maastrichtian). It forms part of the Upper Cretaceous to Teurian (Danian) (lower Paleocene) Tinui Group. It unconformably overlies the Jurassic to Lower Cretaceous Urewera Group or the Upper Cretaceous Matawai Group. It is conformably overlain by the Haumurian to Teurian Whangai Formation. It consist of three members, the Maungataniwha Sandstone Member, the Mutuera Member and the Houpapa Member.[1] It is named for Tahora Station, south of Matawai in the Gisborne Region. The aptly named Maungataniwha (Māori for "mountain of monsters") Sandstone Member is known for its rich reptile fossil remains, first investigated by amateur palaeontologist Joan Wiffen.
Depositional environment
[edit | edit source]The whole of the Tinui Group is interpreted to be an upper Cretaceous transgressive sequence. The Maungataniwha Sandstone Member was deposited in a very shallow water to beach environment. The siltstones of the time-equivalent Mutuera Member are thought to have been deposited in a mid to outer shelf environment. The Houpapa Member is interpreted to be the fill of local channels cut into the underlying strata.[1]
Fossil content
[edit | edit source]Vertebrates
[edit | edit source]Indeterminate dinosaur remains have been recovered from the formation, including indeterminate theropod, sauropod, and ornithischian remains.[4] Other fossils found in the Tahora Formation include plesiosaurs and pterosaurs.[5]
Because of a lack of material, the exact taxonomic placement of the theropod from the Tahora Formation is uncertain, although its discoverer Joan Wiffen considered it possibly a megalosaurid, at the time a poorly defined group of unspecialized large carnivorous dinosaurs. The vertebra was described by Molnar (1981), and was considered an indeterminate theropod by Agnolin et al. (2010).[6][7]
Reptiles
[edit | edit source]Plesiosaurs
[edit | edit source]| Plesiosaurs recorded from Tahora Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Member/Location | Material | Description | Image |
| Tuarangisaurus[8] | T. keyesi | Maungataniwha Sandstone | A nearly complete skull, mandible, rear skull elements, and nine anterior-most cervical vertebrae from the same individual. | An elasmosaurid. | |
Mosasaurs
[edit | edit source]| Mosasaurs recorded from Tahora Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Member/Location | Material | Description | Image |
| Moanasaurus[9] | M. mangahouangae | Maungataniwha Sandstone[10] | A disarticulated skull, vertebrae, ribs and flipper bones. | A Mosasaurini mosasaur. | |
Pterosaurs
[edit | edit source]| Pterosaurs recorded from Tahora Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Member/Location | Material | Description | Image |
| Azhdarchidae[11] | Indeterminate | Maungataniwha Member, Mangahouanga Stream | Distal left ulna, coracoid fragment | ||
Dinosaurs
[edit | edit source]| Dinosaurs recorded from Tahora Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Member/Location | Material | Description | Image |
| Ankylosauria[12][7] | Indeterminate | Maungataniwha Member, Mangahouanga Stream | An incomplete rib and two caudal veterbral centra | ||
| Ornithopoda[7] | Indeterminate | Maungataniwha Member, Mangahouanga Stream | Partial right ilium | ||
| Sauropoda[12] | Indeterminate | Maungataniwha Member | A rib fragment | ||
| Theropoda[7][12] | Indeterminate | Maungataniwha Member, Mangahouanga Stream | Caudal vertebra, pedal phalanx | ||
Invertebrates
[edit | edit source]Invertebrates found in the formation include beetles,[13] ammonites, annelids, belemnites, bivalves, brachiopods, crinoids, crustaceans, gastropods, nautiloids and scaphopods.[3]
See also
[edit | edit source]- List of dinosaur-bearing rock formations
- Geology of the Raukumara Region
- Stratigraphy of New Zealand
- South Polar region of the Cretaceous
References
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- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Weishampel, et al. (2004). "Dinosaur distribution" Pp. 517-607. in Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).. " Pp. 517-607.
- ^ Mangahouanga Stream at Fossilworks.org
- ^ Molnar,R.E.1981.AdinosaurfromNewZealand.Pp.91–96in M.M.Cresswell&P.Vella(eds)GondwanaFive:Proceeding of the Fifth International Gondwanan Symposium. Wellington. A. A., Balkema, Rotterdam.
- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
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- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ GS 14182, Mangahouanga Stream (V19/f133) at Fossilworks.org