Rajasaurus: India's 1st Dinosaur

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Rajasaurus was living in the Indian Peninsula some 67 million years

ago (Upper Cretaceous, Maastrichtian). This was the period when the

Gondwana land had broken and the Indian landmass, broken away from

Africa and South America, was drifting northwards in isolation, in

the form of a big island. The great Himalayan mountain chain was

still to born about 1.5 million years later.

 

20 May 2005

 

The first Indian dinosaur emerges from oblivion

INDO-DINO IMAGE

http://www.jansamachar.net/images/tb-3049.jpg

Rajasaurus narmadensis: Fossilized bones of this species was first

discovered by Suresh Srivastava of GSI during 1982-84 from Rahioli,

Kheda district, Gujarat, India.

 

Fossil bones of Rajasaurus have also been identified from Lameta

Formation (Cretaceous, Maastrichtian) near Jabalpur, Madhya Pradesh

in Central India, indicating its habitat along Narmada river upto

Gujarat.

 

Rajasaurus, a theropod (carnivore), lived along narmada valley. It

had its cousins (eg. Majungatholus) in Africa and Madagascar. The

type specimens of this princely reptile (9 m length, 3 m height) are

to be preserved in the repository unit of GSI at Kolkata.The fossil

collection consists of huge limb bones, vertebrae, pelvic bones,

brain case, post cranial skeleton, parts of lower and upper jaws,

teeth and tail.

 

A team of scientists from India and USA collaborated in assessing the

anatomy of Rajasaurus, thereby successfully reconstructing the total

appearance of it.

 

The history of research pertaining to Rajasaurus began with a

significant event, way back in 1981, when two of the mapping duo of

GSI, G.N. Dwivedi and D.M.Mohabey, Geologists, came across the

workers of ACC Cement quarry at Rahioli, Kheda district, Gujarat. The

workers were curious to know from the geologists what the smooth,

rounded, ball-like structures (of limestone)

that came out of the quary-face at a certain level of the limestone

bed were? The "balls" were dinosaurian eggs.

 

Interestingly the geologists also found that the fossil-egg

containing limestone bed was underlain by a coarse sandstone-

conglomerate horizon yielding a bountiful of an assortment of bone

fossils that could be assigned to dinosaurs (Dwivedi, Mohabey and

Bandopadhyay, 1982).

Suresh Srivastava, Geologist (Sr.) was assigned to collect bone

fossils from a suitable site in the field for examination and study

during the FSP 1982-83 and 1983-84 under the supervision of S.C.Pant

and Dr.U.B.Mathur, the then Directors, Palaeontology Division,

Western Region.

 

A large number of bone fragments were collected and the fossil site

was precisely mapped. The collected

material was housed in the Palaeontology Division, WR, Jaipur for

identification. Two research papers resulted from the collection,

based on the study of some bones and teeth (Mathur and Pant, 1986;

Mathur and Srivastava, 1987). Pressing engagements elsewhere in the

Survey kept further study of the dinosaur fossil collection in

abeyance.

 

With the object to study the whole collection in the totality, which

apparently contained a major part of the skeleton of at least one

individual dinosaur, further work on the fossil material collected in

1982-84 was activated under a MOU with the Punjab University in the

FS 1994-95.

 

An Ameican team of two scientists sponsored by the American Institute

of Indian Studies, New Delhi and the

National Geographic Society, U.S.A., under the aegis of the Punjab

University joined the study group in the winters of 2001.

 

The reconstruction of Rajasaurus is based on about 70% of actual

fossil material dug from the site at Rahioli, Kheda district,

Gujarat, including bits and pieces already known from the Jabalpur

site in Madhya Pradesh.

 

Brief biodata of Rajasaurus

 

Heavy-bodied and stoutly limbed Rajasaurus was a carnivorous

abelisaurid (theropod) dinosaur, inhabiting the environs of present

Narmada river, 6 crores and 70 lac years ago. It is therefore aptly

named as R.narmadensis. Its body measured some 9 m in length and 3 m

in height. The heighest point in its body was in the pelvic region.

It had a somewhat horizontal disposition of the body, unlike the

subvertical stance of the well-known Tyrannosaurus rex. Possessing a

regal

body frame, R.narmadensis was truly the Raja (=King) of dinosaurs of

the Narmada region. Like a true Raja it had a crown of double-crested

horns on the head.

 

Habitat of Rajasaurus

 

Fossilized bones of Rajasaurus typically occur embedded in a coarse

sandstone-conglomerate bed that underlies a sileceous limestone

horizon yielding fossils of dinosaur eggs and egg clutches at

Rahioli, Kheda district, Gujarat. These fossiliferous strata form

part of the Lameta

Formation.

 

The Lameta Formation has a close field association with the Deccan

lava flows or Deccan Trap. The volcanic activity that deposited the

different layers of the Deccan Trap was episodic in occurrence and,

sometimes, there was a considerable period of quiescence between the

eruption of two successive flows. During such quiescent periods the

ground surface upon the latest flow developed into usual land scenery

with rivers, lakes, ponds, etc., with abundant vegetation.

 

Rajasaurus habited such an environ in the quiet phases of the Deccan

volcanic activity. On death its skeletal remains were deposited

alongwith the depopsits of the rivers and the lakes. The

contemporaneous dinosaur community of the meat-eating Rajasaurus also

included some herbivorous sauropod dinosaurs, which are yet to be

fully known. The successively next Deccan volcanic eruption quickly

burried the dinosaurian remains in the sediments, leading to their

good preservation as fossils.

 

The fossil bones of Rajasaurus are found at Rahioli (Gujarat) and in

the headward region of Narmada

at Jabalpur (Madhya Pradesh). In fact a small portion of the upper

jaw of Rajasaurus in the present skeletal reconstruction comes from

the `Bara Shimla Hill', Jabalpur.

 

Palaeogeographic attributes of Rajasaurus

 

Rajasaurus was living in the Indian Peninsula some 67 million years

ago (Upper Cretaceous, Maastrichtian). This was the period when the

Gondwana land had broken and the Indian landmass, broken away from

Africa and South America, was drifting northwards in isolation, in

the form of a big island. The great Himalayan mountain chain was

still to born about 1.5 million years later.

 

This indicates a strong possibility of indigenous features in the

precise form and structure of Rajasaurus, restricted to the Indian

Peninsula. A close ancestral affinity of Rajasaurus is discernible

with Majungatholus of Madagascar and Carnotaurus of South America.

 

 

2005-05-21 12:20:17

Original Source : Geological Survey of India