''Jainosaurus'' is a genus of

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

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their b ...

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 ...

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

and wider

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

, which lived in the

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

(approximately 68

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

). It is thought to have been about the same size as its contemporary relative ''

Isisaurus ''Isisaurus'' (named after the Indian Statistical Institute) is a genus of titanosaurian dinosaur from the Late Cretaceous Lameta Formation of India and Pab Formation of Pakistan. The genus contains a single species, ''Isisaurus colberti''. Di ...

'', measuring long and weighing . The humerus of the type specimen is 134 centimetres long.

History

The type species of ''Jainosaurus'', ''J. septentrionalis'' has a long and complex taxonomic history closely connected to the history of the problematic genera ''

Titanosaurus ''Titanosaurus'' (; ) is a dubious genus of sauropod dinosaurs, first described by Richard Lydekker in 1877.R. Lydekker. (1877). Notices of new and other Vertebrata from Indian Tertiary and Secondary rocks. ''Records of the Geological Survey of ...

'' and ''

Antarctosaurus ''Antarctosaurus'' (; meaning "southern lizard") is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period (geology), Period of what is now South America. The type species, ''Antarctosaurus wichmannianus'', and a second speci ...

''. The first known remains attributable to ''Jainosaurus'', the humerus GSI K22/754, was discovered in 1871 or 1872 by

Henry Benedict Medlicott Henry Benedict Medlicott, FRS (3 August 1829 – 6 April 1905) was an Irish geologist who worked in India. He was a coauthor of a text on the geology of India and is credited with the coining of the term "Gondwana" which was later used to cre ...

, and the holotype remains were found by

Charles Alfred Matley Charles Alfred Matley (1866–1947) was a British paleontologist and geologist in India, the British West Indies and Wales. Matley was educated at Birmingham University, and earned a doctorate in geology (D.Sc.) from the University of London in J ...

between 1917 and 1920 near

Jabalpur Jabalpur, formerly Jubbulpore, is a city situated on the banks of Narmada River in the state of Madhya Pradesh, India. It is the 3rd-largest urban agglomeration of the state and the 38th-largest of the country. Jabalpur is the administrative h ...

in the

Lameta Formation The Lameta Formation, also known as the Infratrappean Beds (not to be confused with the contemporaneous Intertrappean Beds), is a sedimentary geological formation found in Madhya Pradesh, Gujarat, Maharashtra, Telangana, and Andhra Pradesh, Indi ...

. These were named ''

septentrionalis'' by

Friedrich von Huene Baron Friedrich Richard von Hoyningen-Huene (22 March 1875 – 4 April 1969) was a German nobleman paleontologist who described a large number of dinosaurs, more than anyone else in 20th-century Europe. He studied a range of Permo-Carbonife ...

and Matley in 1933. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

of ''J. septentrionalis'' means "northern" in

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

, a reference to the fact that the species was discovered on the

Northern hemisphere The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...

whereas ''Antarctosaurus'' means "saurian from the Southern hemisphere" because its

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

''Antarctosaurus wichmannianus'' was found in

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 generic name honours the Indian paleontologist Sohan Lal Jain, who worked on the cranial nerve impressions in the skull; and in 1982 published a study about the results. Ironically, Jain himself considered the remains synonymous with ''Titanosaurus'' in the 1997 description of ''Isisaurus''. However, Wilson and Upchurch (2003) rejected the synonymy of ''Jainosaurus'' and ''Titanosaurus'' due to the dubious status of the latter. Jainosaurus Skeletal V3 updated

In 1995

Hunt Hunting is the Human activity, human practice of seeking, pursuing, capturing, and killing wildlife or feral animals. The most common reasons for humans to hunt are to obtain the animal's body for meat and useful animal products (fur/hide (sk ...

''et al.'', believing ''Antarctosaurus'' to belong to

Dicraeosauridae Dicraeosauridae is a Family (biology), family of Diplodocoidea, diplodocoid sauropods who are the sister group to Diplodocidae. Dicraeosaurids are a part of the Flagellicaudata, along with Diplodocidae. Dicraeosauridae includes genera such as ''A ...

, made the clearly titanosaurian ''Antarctosaurus septentrionalis'' the type species of a new genus, ''Jainosaurus'', and determined that the braincase, GSI IM K27/497, should be the

lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes ...

. ''Jainosaurus'' was further distinguished from ''Antarctosaurus'' by details of the braincase. In 2009, Jeffrey Wilson and others made a detailed reassessment of ''Jainosaurus septentrionalis'' and confirmed its validity. The

postcrania The postcranium ("behind the cranium"; plural: postcrania) or postcranial skeleton in zoology and vertebrate paleontology is the skeleton apart from the skull. The postcranium encompasses the axial skeleton, which includes the entirety of the verte ...

, which had been assumed lost, were shown to be largely present in the collection of the

Geological Survey of India The Geological Survey of India (GSI) is a scientific agency of India. It was founded in 1851, as a Government of India organization under the Ministry of Mines, one of the oldest of such organisations in the world and the second oldest survey ...

Calcutta Kolkata, also known as Calcutta (List of renamed places in India#West Bengal, its official name until 2001), is the capital and largest city of the Indian States and union territories of India, state of West Bengal. It lies on the eastern ba ...

. They include: dorsal rib fragments (GSI K20/326, K27/425); a caudal vertebra (GSI K20/317), four chevrons (GSI K27/492–494, 496), the left and right scapula (only a cast still extant); a sternal plate (GSI K20/647); a humerus (lacking an inventory number), a radius (GSI K27/490) and an ulna (GSI K27/491). In 1996

Sankar Chatterjee Sankar Chatterjee (born May 28, 1943) is a paleontology, paleontologist, the Paul W. Horn Professor of Earth science, Geosciences at Texas Tech University and curator of Paleontology at the Museum of Texas Tech University. He earned his Doctor of ...

referred a second braincase to the species: ISI R162. Some material from

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

also possibly belongs to ''Jainosaurus''. Wilson e.a. concluded that ''Jainosaurus'' is a valid taxon, clearly distinguishable from ''

''. It would have been a fairly derived member of the

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

, more closely related to South American forms like '' Pitekunsaurus'', '' Muyelensaurus'' and ''

'' than to ''Isisaurus'' or ''

Rapetosaurus ''Rapetosaurus'' ( ) is a genus of titanosaurian sauropod dinosaur that lived in Madagascar from 70 to 66 million years ago, at the end of the Cretaceous Period. Only one species, ''Rapetosaurus krausei'', has been identified. Like other sauropod ...

''.Wilson, Jeffrey; D'Emic, Michael; Rogers, Christina A. Curry; Mohabey, Dhananjay M.; Sen, Subashis, 2009, "Reassessment of Sauropod Dinosaur ''Jainosaurus'' (="Antarctosaurus") ''septentrionalis'' from the Upper Cretaceous of India", ''Contributions from the Museum of Paleontology, University of Michigan'', 32(2): 17–40

References

{{Authority control Titanosauria Dinosaur genera Maastrichtian dinosaurs Fossil taxa described in 1995 Taxa named by Martin Lockley Taxa named by Spencer G. Lucas Dinosaurs of India