''Kaijutitan'' (meaning "

Kaiju is a Japanese term that is commonly associated with media involving giant monsters. Its widespread contemporary use is credited to ''tokusatsu'' (special effects) director Eiji Tsuburaya and filmmaker Ishirō Honda, who popularized the ''kaiju'' ...

titan" after the type of Japanese movie monsters) is a genus of basal

titanosaur Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thr ...

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

from the

Sierra Barrosa Formation The Sierra Barrosa Formation is a geologic formation of the Neuquén Basin in the northern Patagonian provinces of Mendoza Province, Mendoza and Neuquén Province, Neuquén. The formation dates to the Late Cretaceous, Coniacian, middle to late Con ...

from

Neuquén Province Neuquén () is a Provinces of Argentina, province of Argentina, located in the west of the country, at the northern end of Patagonia. It borders Mendoza Province to the north, Rio Negro Province to the southeast, and Chile to the west. It also me ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

and only species is ''Kaijutitan maui''.

Discovery and naming

''Kaijutitan'' was discovered by a team of researchers from the Museo Municipal Argentino Urquiza and the Museo Provincial de Ciencias Naturales “Prof. Dr. Juan Olsacher" from a layer from the Sierra Barrosa Formation, in Cañadón Mistringa, about 9 km southwest of the city of

Rincón de los Sauces Rincón de los Sauces () is a first category municipality and the capital of Pehuenches Department in Neuquén Province, Argentina. History The area was first populated by settlers around the end of the 19th and the start of the 20th century un ...

, in Neuquen,

Description

''Kaijutitan'' is known from the holotype MAU-Pv-CM-522, stored at the Museo Municipal Argentino Urquiza, Paleontología de Vertebrados, Cañadón Mistringa, which is a partial skeleton preserving elements from several parts of the skeleton. It can be distinguished from other titanosaurians through the possession of unique traits: the width between the basal tuberosities is almost four times the width of the foramen magnum; the foramen for the

internal carotid artery The internal carotid artery is an artery in the neck which supplies the anterior cerebral artery, anterior and middle cerebral artery, middle cerebral circulation. In human anatomy, the internal and external carotid artery, external carotid ari ...

is located on the back of the , almost at the middle of the distance between the basipterygoid and the basal tuberosities; the anterior cervical vertebrae have bifid

neural spines Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...

; a medial tuber located behind both metapophyses on both cervical vertebrae; a bifurcated in the spinal sector, generating elongated deep pneumatic cavities on anterior cervical vertebrae; a posteroventral keel on the anterior cervical vertebrae, generated from the convergence of two ridges that originate from the bottom edge of the parapophysis; an accessory lamina that runs from up to the in cervical vertebra; absence of proximal pneumatopores in dorsal ; the prespinal lamina is triangular, which is a product of a dorsal expansion in anterior caudal vertebra; the absence of a ventromedial process in the bottom of the ; the proximal condyle is narrow, with its long axis anteroposteriorly oriented; the tibial cnemial crest projects forward; and foramina at the base of the ascending process of the .

Classification

To test the systematic position of ''Kaijutitan,'' a phylogenetic analysis was conducted to resolve its affinities. A simplified cladogram, showing the results of the analysis, is presented below.

References

{{Taxonbar, from=Q62569760 Titanosauria Dinosaur genera Coniacian dinosaurs Fossil taxa described in 2019 Dinosaurs of Argentina