Dinosaurium
The palaeontology and fossils section of the museum houses a rare and magnificent fossil of the dinosaur, Kotasaurus, dating back to the lower Jurassic age. It is about 160 million years old! It is one of the most well-preserved specimens found in the world. The fossil has been set up in a natural and dynamic posture to bring it to life. At 14 metres in length and over 5 metres in height, it is certainly a sight to behold. The fossils were excavated from Yamanpalli in the Adilabad district of Andhra Pradesh, and mounted by the Geological Survey of India at the museum. Along with this giant mammal standing tall in the centre of the hall, the palaeontology and fossils section has several other important fossils dating back to a similar timeline such as dinosaur eggs, part of a fossilised tree trunk and a giant ammonite. The smaller fossils and their replicas studded on the four columns depict manifestations of smaller flora and fauna. Other exhibits in the form of illustrations such as fossils of dinosaur eggs, marine shells and fossilised tree trunks give visitors an idea of what the planet looked like a long time ago. Another skeleton of a comparable dinosaur, also from the Godavari Valley of India, has been put up by the Indian Statistical Institute (Calcutta).
Dinosaurs: Dinosaurs literally mean “terrible lizards”. They comprise an extinct group of reptiles generally of gigantic dimensions that had the earth under their sway for more than 130 million years. Originating about 200 million years ago from a reptile called Thecodont, this group multiplied with abundant diversification, invading in the process all broad ecological niches available on land and in inland waters, feeding on both plant and flesh.
Types of Dinosaurs
Saurischion with hip structure, resembling that of modern crocodiles and ornithischion with hip structure like that of birds. The sourischions split into sauropods which included giant herbivorous dinosaurs like Brachiosaurus, Apatosaurus and theropods which included flesh eating giants like Tyrannosaurus and Allosaurus. The flesh-eaters walked with the two hind limbs, whereas the plant eaters were mainly quadrupedal. Their diverse shapes included duck-billed, beaked, horned, long and short snouted heads; tank like, ostrich like, cylindrical body with long neck and tail and armoured bodies.
Dinosaurs were also a spectacular failure. They were totally and almost suddenly wiped out from the earth about 65 million years ago, towards the end of the Mesozoic era. A number of reasons like change of vegetation, advent of small mammals etc. were given as causes for their extinction. The most plausible reason, appears to be that of cosmic impact as evidenced by a thin sediment layer with enrichment of Iridium of the end of the Cretoceous.
The dinosaurs were distributed in all the continents of the world. Well preserved skeletal parts were recovered from Africa, America, Antarctica, Asia and Europe. Dinosaurian remains are known from the following Mesozoic sediments from different localities in India: The Upper Triassic and Lower Jurassic sediments of AP (Adilabad district) and Maharashtra (Chandrapur district) Upper Cretaceous sediments of Tamil Nadu (Tiruchy district), Lameta beds of M.P (Jabalpur district) and Gujarat (Kheda district).
Retrieval And Restoration Of Dinosaur Skeleton
In course of search and excavation for dinosaur bones in Yamanapalli area, Adilabad district, Andhra Pradesh, about 840 skeletal parts belonging to sauropod dinosaurs were collected and developed between 1974 and 1980. On examination, it was found that the skeletal remains consisted of at least 12 individuals belonging to a single species. Further study revealed that this dinosaur belonged to a new genus and new sspecies Kotasaurus Yamanpolliensis. In pursuance of a project of GSI for mounting the skeleton of Kotasaurus Yamanpolliensis, processing and treatment of the vast collelction of fossil bones were initiated which took nearly 7 years of time. The work continued under the supervision of former Directors of Palaeontology Division, GSI, SR from time to time. Based on the osteolotgical characters and partial associations, a composite skeleton was assembled at the B.M. Birla Science Centre, Hyderabad. A few of the scenes showing field excavation and laboratory processing have been shown in a panel.
Kotasaurus is a large sauropod with rather slender bones. The composite skeleton at B.M. Birla Science Centre is nearly 14. m long and 4.5 m tall.
Significance of Kotasaurus Skeleton
The sauropod dinosaurs – Barapasaurus fagorei and Kotasaurus Yamanpollieneis from the Lower Jurassic Kota Formation (about 160 million years old) are the earliest known species. Although earlier sauropods have been found in Zimbabwe and China, great interest is attached to the Indian, dinossaurs which had already attained gigantic sizes.
Palaeontologists, till recently had an unsolved problem concerning the origin and evolution of sauropod dinosaurs. Many authorities attempted in vain to find anatomical links between prosauropods and sauropods. This gap has now been bridged by the work of the Indian Statistical Institute and the Geological Survey of India. They are many structural features by which Indian sauropods can be linked with prasauropods on the one hand and with advanced sauropods on the other. Thus, Indian sauropoid can be called a missing link in the evolution of sauropod dinosaurs.
Kota dinosaurs make a significant contribution to the history of the break-up of Gondwanaland, especially the relationship of India with other Gondwanaland continents. It is generally believed that the close of the Palaeozoic, all of the earth’s crust was united to form a supercontinent surrounded by the universal ocean. By the close of the Triassic (about 200 million years old) the supercontinent began to drift apart and the Indian Peninsula, getting separated from the rest of the Gondwanaland, began to drift northward as an island.
The Kota dinosaurs, however, give a somewhat different picture concerning the time of separation of the Indian Peninsula from the rest of the Gondwanaland. Their occurrence in India is a positive proof that there were overland connections between the Peninsular India and other continents during early Jurassic (160 million years old) times.
