Barapasaurus

Barapasaurus (/bəˌrɑːpəˈsɔːrəs/ bə-RAH-pə-SAWR-əs) is a genus of basal sauropod dinosaur from Early Jurassic rocks of India. The only species is B. tagorei. Barapasaurus comes from the lower part of the Kota Formation, that dates back to the Sinemurian and Pliensbachian stages of the early Jurassic. It is therefore one of the earliest known sauropods. Barapasaurus is known from approximately 300 bones from at least six individuals, so that the skeleton is almost completely known except for the anterior cervical vertebrae and the skull. This makes Barapasaurus one of the most completely known sauropods from the early Jurassic.

Barapasaurus
Temporal range: Early Jurassic, 196.5–183 Ma
Barapasaurus DB
Life restoration
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Saurischia
Suborder: Sauropodomorpha
Clade: Sauropoda
Clade: Gravisauria
Genus: Barapasaurus
Jain et al., 1975
Species:
B. tagorei
Binomial name
Barapasaurus tagorei
Jain et al, 1975

Etymology

The name Barapasaurus ("big-legged lizard") is derived from bara meaning 'big' and pa meaning 'leg' in several Indian languages including Bengali; the Greek word sauros means 'lizard'.[1] This name was used as a nomen nudum since a femur measuring over 1.7 m was unearthed at 1961.[1] The specific name tagorei means 'Tagore's', which honors Bengali poet, writer, painter, and musician Rabindranath Tagore. The first year of fieldwork was carried out in the centenary year of Tagore's birth.[1]

Description

Although a very early and unspecialized sauropod, Barapasaurus shows the building plan typical for later, more derived sauropods: the cervical vertebrae were elongated, resulting in a long neck. The trunk was short and holds columnar limbs which indicate an obligate quadrupedal posture.[2][3] Even the size, which is estimated at approximately 14 meters,[4] is comparable with that of later sauropods.[2]

The vertebral column already shows many traits that are typical for later sauropods which allowed them to attain great body sizes, although in later sauropods these traits are much more developed. The central and neural spines show early hints of hollowing as a weight-saving measure. The dorsal vertebrae are stabilized with hyposphene-hypantrum articulations, accessory projections that link the vertebrae with each other. The sacrum is strengthened through an additional fourth sacral vertebra.[3]

From the skull, only three whole teeth and three crowns are known. The largest known tooth is 5.8 cm in height. Like that of later sauropods, the teeth are spoon shaped and show wrinkled enamel. A basal trait is the coarse serration.[3]

Classification

Cladogram of basal Sauropoda
 Sauropoda 

 Jingshanosaurus

   

 Antetonitrus

   

 Chinshakiangosaurus

   

 Kotasaurus

   

 Barapasaurus

   

 Vulcanodon

   
 Eusauropoda 

 Shunosaurus

   

 Camarasaurus

 Omeisaurus

Bandyopadhyay 2010[3]

The relationships of this genus within the Sauropoda are debated. When first described in 1975, it was not attributed to one specific group at all, although the presence of many basal, prosauropod-like features was noted.[1] Since 1984, Barapasaurus was united with another early sauropod, Vulcanodon, in a family called Vulcanodontidae, although this family was declared invalid by Paul Upchurch in 1995 because it was recognized as polyphyletic. Upchurch erected a clade named Eusauropoda that includes all known sauropods except some very basal forms. While Vulcanodon was classified outside the Eusauropoda, Barapasaurus was classified inside it, which means that Barapasaurus is more derived than Vulcanodon.[3][5] Although Upchurch's classification was accepted by most paleontologists, a recent study from Bandyopadhyay and colleagues came to a contrary conclusion: these paleontologists stated that Barapasaurus was in fact more basal than Vulcanodon and removed it from Eusauropoda.[3]

Discovery

All known fossils come from a single locality in the vicinity of the village of Pochampally, (Pochampally is a mandal in Nalgonda District, Telangana, in southern India and is popularly known as Silk City of India, India.[1] The first bones were discovered in 1958, but most specimens were unearthed in 1960 and 1961.[3] In 1975, the finds were described scientifically by paleontologist Sohan Jain and colleagues.[1] In 2010, a more detailed osteological description was published by Bandyopadhyay and colleagues.[3] The material is archived in the paleontological collection of the Indian Statistical Institute (ISI), while a majority of the bones are part of a mount at the Geological Museum of the ISI.[3]

Habitat

Barapasaurus comes from clay and sandstone that belongs to the lower part of the Kota Formation. Other vertebrates of this part include another early sauropod, Kotasaurus, as well as the mammals Kotatherium, Indotherium and Indozostrodon. The upper part of the Kota Formation additionally contained a pterosaur, a turtle, two rhynchocephalians, a lepidosaur and some mammals.[3]

Taphonomy

The approximately 300 bones were found together with large trunks of trees scattered over an area of 276 square meters. Although one of the specimens was found partly articulated, most bones were found disarticulated. Because there are six left femora, the total number of individuals is at least six.[3]

Bandyopadhyay and colleagues (2002, 2010) interpret this assemblage as a herd that died due to a catastrophic event, likely a flood. This flood could have unearthed the trees and transported both trees and Barapasaurus a distance before they began to decompose. After decomposition progressed, the bones began to disarticulate. The disarticulated skull bones were removed by the water stream because they were light, leaving only the heavy postcranial bones at the site, which would explain why no skull bones were found.[3]

References

  1. ^ a b c d e f Jain, S. L.; T. S. Kutty; T. Roy-Chowdhury; S. Chatterjee (1975-02-18). "The Sauropod Dinosaur from the Lower Jurassic Kota Formation of India". Proceedings of the Royal Society B. 188 (1091): 221–228. doi:10.1098/rspb.1975.0014. ISSN 1471-2954. Retrieved 2012-10-13.
  2. ^ a b Jain, S. L.; T. S. Kutty; T. Roy-Chowdhury; S. Chatterjee (1979). "Some characteristics of Barapasaurus tagorei, a sauropod dinosaur from the Lower Jurassic of Deccan, India". Proceedings of the IV International Gondwana Symposium, Calcutta. 1. pp. 204–216.
  3. ^ a b c d e f g h i j k l Bandyopadhyay, Saswati; David D. Gillette; Sanghamitra Ray; Dhurjati P. Sengupta (2010). "Osteology of Barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India". Palaeontology. 53 (3): 533–569. doi:10.1111/j.1475-4983.2010.00933.x. ISSN 1475-4983.
  4. ^ Glut, Donald F. (1997). Dinosaurs, the encyclopedia. McFarland & Company, Inc. Publishers. ISBN 978-0-375-82419-7.
  5. ^ Upchurch, Paul (1995-09-29). "The Evolutionary History of Sauropod Dinosaurs". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 349 (1330): 365–390. doi:10.1098/rstb.1995.0125. ISSN 1471-2970.

External links

1975 in paleontology

Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1975.

Eusauropoda

Eusauropoda (meaning "true sauropods") is a derived clade of sauropod dinosaurs. Eusauropods represent the node-based group that includes all descendant sauropods starting with the basal eusauropods of Shunosaurus, and possibly Barapasaurus, and Amygdalodon, but excluding Vulcanodon and Rhoetosaurus. The Eusauropoda was coined in 1995 by Paul Upchurch to create a monophyletic new taxonomic group that would include all sauropods, except for the vulcanodontids.Eusauropoda are herbivorous, quadrupedal, and have long necks. They have been found in South America, Europe, North America, Asia, Australia, and Africa. The temporal range of Eusauropoda ranges from the early Jurassic to the Latest Cretaceous periods. The most basal forms of eusauropods are not well known and because the cranial material for the Vulcanodon is not available, and the distribution of some of these shared derived traits that distinguish Eusauropoda is still completely clear.

Ferganasaurus

Ferganasaurus was a genus of dinosaur first formally described in 2003 by Alifanov and Averianov. The type species is Ferganasaurus verzilini. It was a sauropod similar to Rhoetosaurus. The fossils were discovered in 1966 in Kyrgyzstan from the Balabansai Formation and date to the Callovian stage of the Middle Jurassic.

Flagellicaudata

Flagellicaudata is a clade of Dinosauria. It belongs to Sauropoda and includes two families, the Dicraeosauridae and the Diplodocidae.

Gravisauria

Gravisauria is a clade of sauropod dinosaurs consisting of some genera, Vulcanodontidae and Eusauropoda.

Huangshanlong

Huangshanlong is a genus of mamenchisaurid dinosaurs native to the Anhui province of China. It contains a single species, Huangshanlong anhuiensis. H. anhuiensis represents, along with Anhuilong and Wannanosaurus, one of three dinosaurs fround in Anhui province.

Indroda Dinosaur and Fossil Park

The Indroda Dinosaur and Fossil Park in Ahmedabad in the state of Gujarat, India, is a park which houses the fossilized remains and the petrified eggs of the dinosaurs. It is technically a man made fossil park and not the actual nesting grounds where the dinosaurs lived. The eggs and fossils on display here are actually from the world's 3rd largest dinosaur fossil excavation site and 2nd largest hatchery located at Raiyoli, Balasinor, Gujarat. The Park was set up by the Geological Survey of India and is the only dinosaur museum in the country.The Park is run by the Gujarat Ecological and Research Foundation (GEER) and has been called India's Jurassic Park. The oldest record of dinosaur bone fossils is of middle Jurassic period and they are found from Parcham formation of Kutch basin. The fossils which were found in Upper Cretaceous formations in the region date back 66 million years ago. The eggs are of different sizes, some the size of cannon balls. Fossil trackways of these gargantuan animals are also on display in the park.Dinosaurs that are on display include Tyrannosaurus rex, Megalosaurus, Titanosaurus, Barapasaurus, Brachiosaurus, Antarctosaurus, Stegosaurus and Iguanodon. The park displays life-size models of the dinosaurs along with details of each period in which they existed and characteristics of the animals.The fossils were found in the Songhir Bagh Basin, the Himatnagar basin of Balasinor, south-eastern parts of Kheda, Panchmahal and Vadodara districts of the state.

Kaijutitan

Kaijutitan (meaning "Kaiju titan" after the type of Japanese movie monsters) is a genus of basal titanosaur dinosaur from the Sierra Barrosa Formation from Neuquén Province in Argentina. The type and only species is Kaijutitan maui.

Kota Formation

The Kota Formation is a geological formation in India. The dates for the Kora Formation are uncertain, but it dates from the Early Jurassic to Early Cretaceous, and is split into a Lower Member and Upper Member. The lower members is though to be Hettangian-Pliensbachian.

Kotasaurus

Kotasaurus ( KOH-tə-SAWR-əs; meaning "Kota Formation lizard") is a genus of sauropod dinosaur from the Early Jurassic period (Sinemurian–Pliensbachian). The only known species is Kotasaurus yamanpalliensis. It was discovered in the Kota Formation of Telangana, India and shared its habitat with the related Barapasaurus. So far the remains of at least 12 individuals are known. The greater part of the skeleton is known, but the skull is missing, with the exception of two teeth. Like all sauropods, it was a large, quadrupedal herbivore with long neck and tail.

Neosauropoda

Neosauropoda is a clade within Dinosauria, coined in 1986 by Argentine paleontologist José Bonaparte and currently described as Saltasaurus loricatus, Diplodocus longus, and all animals directly descended from their most recent common ancestor. The group is composed of two subgroups: Diplodocoidea and Macronaria. Arising in the early Jurassic and persisting until the Cretaceous-Paleogene extinction event, Neosauropoda contains the majority of sauropod genera, including genera such as Apatosaurus, Brachiosaurus, and Diplodocus. It also includes giants such as Argentinosaurus, Patagotitan and Sauroposeidon, and its members remain the largest land animals ever to have lived.When Bonaparte first coined the term Neosauropoda in 1986, he described the clade as comprising “end-Jurassic” sauropods. While Neosauropoda does appear to have originated at the end of the Jurassic period, it also includes members through the end of the Cretaceous. Neosauropoda is currently delineated by specific shared, derived characteristics rather than the time period in which its members lived. The group was further refined by Upchurch, Sereno, and Wilson, who have identified thirteen synapomorphies shared among neosauropods. As Neosauropoda is a subgroup of Sauropoda, all members also display basic sauropod traits such as large size, long necks, and columnar legs.

Patagosaurus

Patagosaurus (meaning "Patagonia lizard") is an extinct genus of eusauropodan dinosaur from the Middle Jurassic of Patagonia, Argentina. It was first found in deposits of the Cañadón Asfalto Formation, which date to around 165 to 161 million years ago. Although originally twelve specimens were assigned to the taxon, at least one of them may belong to a different genus. Patagosaurus probably lived alongside genera as Piatnitzkysaurus, Condorraptor, and Volkheimeria.

Since Patagosaurus is known from many specimens, including at least one juvenile, its anatomy and growth are fairly well understood. Both ages exhibit the typical features of a sauropod, a long neck, small head, a long tail, and being quadrupedal. The juvenile exhibits features different from the adult in regions like the mandible, pectoral girdle, pelvis and hindlimb, although overall their anatomy is quite similar. The many known specimens help fill in gaps in the anatomy of the genus, such as the forelimb and skull. Parts of the skeleton, like the pectoral girdle, tibia, and pubis are more robust, while others, like the forelimb and ischium, are more gracile. The material of Patagosaurus is similar to closely related taxa like Cetiosaurus and Volkheimeria, more primitive genera such as Barapasaurus and Amygdalodon, and more derived sauropods like Diplodocus and Camarasaurus.

Shunosaurus

Shunosaurus, meaning "shu lizard", is a genus of sauropod dinosaur from Early Jurassic (Oxfordian) beds in Sichuan Province in China, approximately 159±2 million years ago. The name derives from "Shu", an ancient name for the Sichuan province.

Tambatitanis

Tambatitanis is an extinct genus of titanosauriform dinosaur from the Early Cretaceous (probably early Albian) of Japan. It is known from a single type species, Tambatitanis amicitiae. It was probably around 14 meters long and its mass was estimated at some 4 tonnes. It was a basal titanosauriform and possibly belonged to the Euhelopodidae.

Tehuelchesaurus

Tehuelchesaurus (tay-WAYL-chay-SAWR-us) is a genus of dinosaur. It is named in honor of the Tehuelche people, native to the Argentinian province of Chubut, where it was first found.

Toarcian

The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian.The Toarcian age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age.

Vulcanodon

Vulcanodon (meaning "volcano tooth") is an extinct genus of sauropod dinosaur from the Early Jurassic of southern Africa. The only known species is V. karibaensis. Discovered in 1969 in Rhodesia (now known as Zimbabwe), it was regarded as the earliest known sauropod for decades, and is still one of the most primitive sauropods that has been discovered. As a quadrupedal, ground-dwelling herbivore, Vulcanodon already showed the typical sauropod body plan with column-like legs and a long neck and tail. It was smaller than most other sauropods, measuring approximately eleven metres (35 ft) in length. Vulcanodon is known from a fragmentary skeleton including much of the pelvic girdle, hindlimbs, forearms, and tail, but lacking the trunk and neck vertebrae as well as the skull.

Originally, this genus was believed to be a prosauropod because of the knife-shaped teeth found near its fossils, which fit in with the idea that prosauropods were omnivorous. Scientists now know that the teeth belonged to an unidentified theropod that may have scavenged on the Vulcanodon carcass. Vulcanodon is now known to be a true sauropod. Upon the discovery of the related Tazoudasaurus, both animals were unified in the family Vulcanodontidae, though this has not been universally accepted.

Vulcanodontidae

The Early Jurassic sauropod dinosaurs Zizhongosaurus, Barapasaurus, Tazoudasaurus, and Vulcanodon may form a natural group of basal sauropods called the Vulcanodontidae. Basal vulcanodonts include some of the earliest known examples of sauropods. The family-level name Vulcanodontidae was erected by M.R. Cooper in 1984. In 1995 Hunt et al. published the opinion that the family is synonymous with the Barapasauridae. One of the key morphological features specific to the family is an unusually narrow sacrum.

Zizhongosaurus

Zizhongosaurus (meaning "Zizhong lizard") is a genus of basal herbivorous sauropod dinosaur which lived in the Early Jurassic Period of China. It was a large-bodied herbivore characterized by a long neck.

The type species Zizhongosaurus chuanchengensis was named in 1983 by Dong Zhiming, Zhou Shiwu and Zhang Yihong. The generic name is derived from Zizhong County in Sichuan Province. The specific name refers to the town of Chuancheng.

The type specimens consist of three syntypes: V9067.1 is a partial dorsal vertebra; V9067.2 is a humerus or upper arm; and V9067.3 is a pubis. All specimens likely were part of a single skeleton. Zizhongosaurus was described as a small species.In 1999 Li Kui mentioned a second species: Zizhongosaurus huangshibanensis but this has remained an undescribed nomen nudum.

Zizhongosaurus was originally assigned to the Cetiosaurinae but later authors have placed it in either the Vulcanodontidae, as a relative of Barapasaurus, or the Shunosaurinae. It is today often considered a nomen dubium.

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