Barapasaurus

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Barapasaurus
Live artistic representation of Barapasaurus

Live artistic representation of Barapasaurus

Temporal occurrence
Lower Jurassic ( Sinemurian to Pliensbachian )
199.3 to 182.7 million years
Locations
Systematics
Dinosaur (dinosauria)
Lizard dinosaur (Saurischia)
Sauropodomorpha
Sauropods (Sauropoda)
Barapasaurus
Scientific name
Barapasaurus
Jain , Kutty , Roy-Chowdhury & Chatterjee , 1975
Art
  • Barapasaurus tagorei

Barapasaurus is a genus of dinosaurs and a very early representative of the sauropods . The only species Barapasaurus tagorei comes from the Lower Jurassic India . So far, the remains of at least six individuals are known, with the skeleton being almost completely known except for the front section of the cervical spine and the skull. This makes Barapasaurus one of the most fully known sauropods of the Lower Jurassic and is of great importance for understanding the early evolution of this group.

features

As one of the oldest known sauropods, Barapasaurus already showed the body structure typical of later sauropods with elongated cervical vertebrae, a short trunk and columnar legs, which indicate an obligatory four-legged mode of locomotion. The body length is estimated to be around 14 meters and was thus already comparable to that of later sauropods.

The spine already showed adaptations to a large body size, as it was typical for later sauropods: The bone mass of the cervical and dorsal vertebrae was reduced by cavities in the vertebral bodies and the spinous processes , which reduced the weight. The vertebrae were stabilized by additional connecting elements , the hyposphene-hypantrum connections . Meanwhile, the sacrum was reinforced by an additional, fourth sacral vertebra.

Only three whole teeth and three tooth crowns are known of the skull, the largest tooth including the root being 5.8 cm high. As with later sauropods, these teeth were spoon-shaped while the tooth enamel was folded. An original feature was the rough serration of the cutting edges.

Systematics

Cladogram , simplified from Bandyopadhyay and colleagues, 2010:
  Sauropoda  

 Jingshanosaurus


     

 Antetonitrus


     

 Chinshakiangosaurus


     

 Kotasaurus


     

 Barapasaurus


     

 Vulcanodon


     
  Eusauropoda  

 Shunosaurus


     

 Camarasaurus


   

 Omeisaurus











Template: Klade / Maintenance / Style
Systematic position of Barapasaurus

The relationship between Barapasaurus and other early sauropods is controversial. In the 1975 first description , Sohan Jain and colleagues did not attribute Barapasaurus to any of the families then differentiated , but noted a number of very original features. Since 1984 Barapasaurus is often classified together with the also very original Vulcanodon in a family called Vulcanodontidae . Paul Upchurch (1995) defines a new group, the Eusauropoda , which includes all sauropods with the exception of a few very original representatives including the Vulcanodontidae. Unlike Vulcanodon , Upchurch classifies Barapasaurus within the Eusauropoda; this interpretation is followed by most of the subsequently published studies. However, Saswati Bandyopadhyay and colleagues (2010) come to the opposite conclusion that Barapasaurus was more original than Vulcanodon and must be classified outside of the Eusauropoda.

Research history and naming

All known fossils come from a single site near the village of Pochampalli in the Indian Deccan . The first Barapasaurus fossils were found in 1958, most of the fossils were recovered from excavations in 1960 and 1961. In 1975 they were finally scientifically described by Sohan Jain and colleagues. A more extensive description of the skeleton followed in 2010. Today the finds are archived in the paleontological collection of the Indian Statistical Institute (Indian Federal Statistical Office, ISI); the majority of the original fossils are mounted in a skeleton reconstruction in the geological museum of the ISI.

The name Barapasaurus is derived from the words bara - "big" and pa - "leg" in various Indian languages ​​and the Greek sauros - "lizard", which means "big-legged lizard". The namesake state that they have been using this name as the nickname for the new dinosaur since the early stages of the 1961 excavations, when a thighbone over 1.7 meters long was discovered. The second part of the species name, tagorei , is said to remind of the famous Indian poet Rabindranath Thakur (Rabindranath Tagore is an older spelling). The first year of the excavation would also have been Thakur's hundredth birthday.

Paleohabitat

Barapasaurus comes from clay and sandstones of the lower section of the Kota Formation . Other vertebrate finds in this section include the original sauropod Kotasaurus and the mammals Kotatherium , Indotherium and Indozostrodon . The upper part of the formation also contains fish fossils, a pterosaur , a turtle, two sphenodontics , a scaled lizard and various other mammal genera.

Taphonomy

The total of about 300 bones were found together with large fossil tree trunks on an area of ​​about 276 square meters. Although one of the skeletons was partially discovered in the skeletal system, most of the bones were incoherent. Using the six left thigh bones, the total number of individuals is estimated to be at least six.

According to Bandyopadhyay and colleagues (2002, 2010), these fossils are a herd of Barapasaurus that was killed by a catastrophic event, possibly a storm surge. The storm surge would also have uprooted the trees that were found along with the Barapasaurus fossils. After the carcasses were carried some distance by the water, they began to rot and the bones left the skeletal structure. The light and fragile skull bones were washed away by water, with only the heavier bones of the post-cranium remaining at the current location.

Individual evidence

  1. ↑ a b Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. In: Palaeontology. Vol. 53, No. 3, 2010, ISSN  0031-0239 , pp. 533-569, doi : 10.1111 / j.1475-4983.2010.00933.x .
  2. ↑ a b Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. Cuncluding remarks. In: Palaeontology. Vol. 53, No. 3, 2010, pp. 533-569, here p. 565, doi : 10.1111 / j.1475-4983.2010.00933.x .
  3. ^ Donald F. Glut : Dinosaurs. The Encyclopedia. McFarland & Company, Inc. Publishers, Jefferson NC et al. 1997, ISBN 0-89950-917-7 .
  4. ↑ Sohan L. Jain, TS Kutty, Tapan Roy-Chowdhury, Sankar Chatterjee : Some characteristics of Barapasaurus tagorei, a sauropod dinosaur from the Lower Jurassic of Deccan, India. In: Fourth International Gondwana Symposium, Calcutta, 1977. Papers. Vol. 1. Hindustan Publishing Corporation, Delhi 1979, pp. 204-216, here p. 205.
  5. ↑ Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of Barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. Skull and teeth. In: Palaeontology. Vol. 53, No. 3, 2010, pp. 533-569, here pp. 542-544, doi : 10.1111 / j.1475-4983.2010.00933.x .
  6. ↑ Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of Barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. Present work. Text fig. 17. In: Palaeontology. Vol. 53, No. 3, 2010, pp. 533-569, here p. 562, doi : 10.1111 / j.1475-4983.2010.00933.x .
  7. ^ John S. McIntosh: Sauropoda. In: David B. Weishampel , Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . University of California Press, Berkeley CA et al. 1990, ISBN 0-520-06726-6 , pp. 345-401, here pp. 376-377.
  8. ↑ Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of Barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. Present work. In: Palaeontology. Vol. 53, No. 3, 2010, pp. 533-569, here p. 564, doi : 10.1111 / j.1475-4983.2010.00933.x .
  9. ↑ Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of Barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. Present work. Previous work on classification of Barapasaurus. In: Palaeontology. Vol. 53, No. 3, 2010, pp. 533-569, here pp. 562-564, doi : 10.1111 / j.1475-4983.2010.00933.x .
  10. ↑ Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of Barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. Acknowledgments. In: Palaeontology. Vol. 53, No. 3, 2010, pp. 533-569, here pp. 565-566, doi : 10.1111 / j.1475-4983.2010.00933.x .
  11. ↑ a b c d Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of Barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. Taphonomy. In: Palaeontology. Vol. 53, No. 3, 2010, pp. 533-569, here pp. 538-539, doi : 10.1111 / j.1475-4983.2010.00933.x .
  12. ^ A b Sohan L. Jain, TS Kutty, Tapan Roy-Chowdhury, Sankar Chatterjee: The Sauropod Dinosaur from the Lower Jurassic Kota Formation of India. In: Proceedings of the Royal Society of London. Series B: Biological Sciences. Vol. 188, No. 1091, 1975, ISSN  0080-4649 , pp. 221-228, doi : 10.1098 / rspb.1975.0014 .
  13. ↑ Saswati Bandyopadhyay, David D. Gillette, Sanghamitra Ray, Dhurjati P. Sengupta: Osteology of Barapasaurus tagorei (Dinosauria: Sauropoda) from the Early Jurassic of India. Present work. Material. In: Palaeontology. Vol. 53, No. 3, 2010, pp. 533-569, here pp. 539-541, doi : 10.1111 / j.1475-4983.2010.00933.x .

Web links

Commons : Barapasaurus  - collection of images, videos and audio files