''Taniwhasaurus'' (from the Māori ''

taniwha In Māori mythology, taniwha () are large supernatural beings that live in deep pools in rivers, dark caves, or in the sea, especially in places with dangerous currents or deceptive breakers (giant waves). They may be considered highly respected ...

'', a supernatural, aquatic creature, and the Greek (), meaning lizard) is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

mosasaur Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Greek ' meaning 'lizard') comprise a group of extinct, large marine reptiles from the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Maastricht on th ...

(carnivorous marine

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

s) which inhabited

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

and

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

.Caldwell MW, Konishi T, Obata I, Muramoto K. 2008. New species of ''Taniwhasaurus'' (Mosasauridae, Tylosaurinae) from the upper Santonian-lower Campanian (Upper Cretaceous) of Hokkaido, Japan. ''Journal of Vertebrate Paleontology'' 28 (2): 339-348. during the Late Cretaceous. The genus was a close relative of the genus ''

Tylosaurus ''Tylosaurus'' (from the ancient Greek (') 'protuberance, knob' + Greek (') 'lizard') is a genus of mosasaur, a large, predatory marine reptile closely related to modern monitor lizards and to snakes, from the Late Cretaceous. Description A ...

''.

Species

''T. oweni''

''Taniwhasaurus oweni'', the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the genus ''Taniwhasaurus'', was a relatively medium-sized mosasaur, measuring long and weighing . It was named and described by

James Hector Sir James Hector (16 March 1834 – 6 November 1907) was a Scottish-New Zealand geologist, naturalist, and surgeon who accompanied the Palliser Expedition as a surgeon and geologist. He went on to have a lengthy career as a government employe ...

in 1874 from a fossil specimen found in the

late Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian sp ...

Conway Formation The Conway Formation is a Campanian to Danian geologic formation in the South Island of New Zealand and therefore crosses the Cretaceous–Paleogene boundary. Plesiosaur remains are among the fossils that have been recovered from its strata. The ...

outcrops at Haumuri Bluff, New Zealand (a stage known in the

New Zealand geologic time scale While also using the international geologic time scale, many nations–especially those with isolated and therefore non-standard prehistories–use their own systems of dividing geologic time into epochs and faunal stages. In New Zealand, these epo ...

Haumurian While also using the international geologic time scale, many nations–especially those with isolated and therefore non-standard prehistories–use their own systems of dividing geologic time into epochs and faunal stages. In New Zealand, these epo ...

). The skeletal material consisted of a skull, vertebrae, and paddles, which occurred in three separate sections but were all thought to belong to the same species. Further cranial material and vertebrae were collected in 1999. Discovered remains of ''T. oweni'' suggests that this species had powerful muscular

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

that were short and wide, with paddle bones that had

phalange The phalanges (singular: ''phalanx'' ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones. ...

s. ''Tylosaurus haumuriensis'', which was also named by Hector from the front parts of the jaws, was found to be a junior taxon of ''T. oweni''.

''T. capensis''

''Tylosaurus capensis'' was described in 1912 by Broom from Santonian deposits in Pondoland,

based on a few fragmentary pieces of the jaw bone and a single vertebra. In 2019, a re-examination of tylosaurine taxa by Paulina Jimenez-Huidobro and Michael Caldwell of the

University of Alberta The University of Alberta, also known as U of A or UAlberta, is a public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford,"A Gentleman of Strathcona – Alexander Cameron Rutherfor ...

found that the holotype specimen is more characteristic of ''Taniwhasaurus'' than ''Tylosaurus'', but also found that the fossils were too poorly preserved to identify to the species and reidentified them as ''Taniwhasaurus'' instead. Nevertheless, the study also moved the taxon ''T. capensis'' to ''Taniwhasaurus''.

''T. antarcticus''

The genus ''Lakumasaurus'' was described in 2002 by Novas ''et al.'' from a skull, rib fragments, and several vertebrae found in the

Santa Marta Formation The Santa Marta Formation is a geologic formation in Antarctica. It, along with the Hanson Formation and the Snow Hill Island Formation, are the only formations yet known on the continent where dinosaur fossils have been found. The formation outcr ...

James Ross Island James Ross Island is a large island off the southeast side and near the northeastern extremity of the Antarctic Peninsula, from which it is separated by Prince Gustav Channel. Rising to , it is irregularly shaped and extends in a north–south ...

, Antarctica. When the type material was reexamined in 2007, James E. Martin and Marta Fernández determined ''Lakumasaurus'' to be a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of ''Taniwhasaurus'' and recombined the species ''Lakumasaurus antarcticus'' as ''T. antarcticus''.

''T. mikasaensis''

"Yezosaurus" was the name given to an undescribed genus of prehistoric marine

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

. Originally thought to be a

Tyrannosaur Tyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinent be ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

, it was later identified as a

ichthyosaur Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, altho ...

which lived in what is now Japan.''Yezosaurus'' in the Dinosaur Encyclopaedia
at Dino Russ's Lair The "

", "Yezosaurus mikasaensis", was coined by Obata and Muramoto in 1977, but was not formally described until 2008, when the species ''T. mikasaensis'' was described by Caldwell ''et al'' (thereby making ''Y. mikasaensis'' a ''

nomen nudum In taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published with an adequate descr ...

''). Jimenez-Huidobro & Caldwell (2019) argued that there is not enough sufficient fossil evidence to distinguish between ''T. mikasaensis'' and ''T. oweni'' and thus reassigned the former to ''Taniwhasaurus'' indet.

References

{{Taxonbar, from=Q136278 Mosasaurids Extinct reptiles of New Zealand Fossil taxa described in 1874 Fossil taxa described in 2002 Fossil taxa described in 2008 James Ross Island Prehistoric reptiles of Antarctica Fossils of Japan Mosasaurs of Asia Mosasaurs of Oceania