Kokoamu Greensand | |
---|---|
Stratigraphic range: Chattian ~ | |
Type | Geological formation |
Unit of | Otiake Group |
Underlies | Otekaike Limestone |
Overlies | Earthquakes Marl |
Thickness | up to 7 metres (20 ft) |
Lithology | |
Primary | Greensand |
Other | Limestone |
Location | |
Coordinates | 44°42′S170°30′E / 44.7°S 170.5°E |
Approximate paleocoordinates | 50°30′S176°18′W / 50.5°S 176.3°W |
Region | Canterbury, Otago |
Country | New Zealand |
Extent | Around Duntroon, South Island |
The Kokoamu Greensand is a geological formation found in New Zealand. It is a fossil-bearing, late Oligocene, greensand rock unit of the eastern South Island, especially the Waitaki District of North Otago and the southern Canterbury region. The formation was named by geologist Maxwell Gage in the 1950s. In North Otago it underlies the thicker and harder Otekaike Limestone. [1] The formation gets its green colour from the mineral glauconite which forms slowly on the ocean floor.
The formation was laid down in shallow seas some 26-30 million years ago. It contains abundant microfossils of foraminifera, ostracods and coccoliths, those of larger marine invertebrates such as the shells of brachiopods, gastropods and scallops, as well as corals, echinoderms, and crustaceans. Vertebrates found in the formation include fish, penguins and cetaceans. Many of the fossils discovered in the formation are held in the Geology Museum of the University of Otago. [1]
Archaeoceti, or Zeuglodontes in older literature, is a paraphyletic group of primitive cetaceans that lived from the Early Eocene to the late Oligocene. Representing the earliest cetacean radiation, they include the initial amphibious stages in cetacean evolution, thus are the ancestors of both modern cetacean suborders, Mysticeti and Odontoceti. This initial diversification occurred in the shallow waters that separated India and Asia 53 to 45 mya, resulting in some 30 species adapted to a fully oceanic life. Echolocation and filter-feeding evolved during a second radiation 36 to 35 mya.
Prosqualodon is an extinct genus of Early to Middle Miocene cetacean from Argentina, Australia, New Zealand and Venezuela.
Mammalodon is an extinct genus of archaic baleen whale belonging to the family Mammalodontidae.
Waipatia is an extinct genus of odontocetes from the late Oligocene (Chattian) of New Zealand.
Australodelphis mirus is an extinct Pliocene dolphin. A. mirus is known from fossils found in the Sørsdal Formation, Mule Peninsula, Vestfold Hills, East Antarctica. The genus has been described as an example of convergent evolution with beaked whales.
Kentriodontidae is an extinct family of odontocete whales related to modern dolphins. The Kentriodontidae lived from the Oligocene to the Pliocene before going extinct.
Waipatiidae is an extinct family of odontocetes currently known from the Oligocene of the Pacific Ocean and possibly Europe and the Caucasus.
Cetotheriidae is a family of baleen whales. The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by Fordyce & Marx 2013 recovered the living pygmy right whale as a member of Cetotheriidae, making the pygmy right whale the only living cetotheriid, other authors either dispute this placement or recover Neobalaenidae as a sister group to Cetotheriidae.
Kairuku is an extinct genus of penguin. It contains three species, K. grebneffi, K. waitaki and K. waewaeroa. This taxon is known from bones from 27 MYA, from the Kokoamu Greensand Formation of New Zealand. It was historically referred to as Palaeeudyptes.
Otekaikea is an extinct genus of toothed whale closely related to Waipatia. It is known from the late Oligocene (Chattian) of New Zealand.
Tohoraata is a genus of eomysticetid baleen whale from the Late Oligocene (Chattian) of New Zealand. There are two recognized species, T. raekohao and T. waitakiensis.
The Pisco Formation is a geologic formation located in Peru, on the southern coastal desert of Ica and Arequipa. The approximately 640 metres (2,100 ft) thick formation was deposited in the Pisco Basin, spanning an age from the Middle Miocene up to the Early Pleistocene, roughly from 15 to 2 Ma. The tuffaceous sandstones, diatomaceous siltstones, conglomerates and dolomites were deposited in a lagoonal to near-shore environment, in bays similar to other Pacific South American formations as the Bahía Inglesa and Coquimbo Formations of Chile.
Microcetus is a genus of extinct odontocete from the late Oligocene (Chattian) of Nordrhein-Westfalen, Germany.
Matapanui is a genus of eomysticetid baleen whale from the Late Oligocene Kokoamu Greensand of New Zealand.
Horopeta is a genus of baleen whale from the Late Oligocene (Chattian) Kokoamu Greensand of New Zealand.
Notocetus is an extinct genus of river dolphin belonging to Squalodelphinidae. Known specimens have been found in Early Miocene marine deposits from Argentina, Italy and Peru.
Tangaroasaurus is an extinct genus of squalodontid whale from the Miocene of New Zealand. It contains a single species, Tangaroasaurus kakanuiensis. Similar to Basilosaurus and its close relative Squalodon, it was originally thought to be a species of marine reptile. Parts of the Holotype are presumably lost. Its name comes from Tangaroa, the Maori god of the sea, while the suffix -saurus comes from the Latin word for reptile, the group that Tangaroasaurus was originally placed in.
Nihoroa is an extinct genus of waipatiid odontocete cetacean from the glauconitic Otekaike Limestone in North Otago; New Zealand. The type species is N. reimaea, known from only the holotype which comprises various skull elements.