November 15, 2003

The word ‘Dinosaur’ is the combination of the two words, ‘Dino’ and ‘Saur’. ‘Dino’ is a Greek word which means ‘terrible’ and ‘saur’ means ‘Lizard’, a reptile. So dinosaur is a terrible lizard which causes terror because of its appearance. The dinosaurs were the largest reptiles that existed on this planet million of years ago. They were of enormous size. Brontosaurus, one of the largest plant eating dinosaurs, for example was about 65 feet long and weighed about 50000 pounds. There were dinosaurs even larger and heavier than Brontosaurus.

Some dinosaurs even weighed more than 80 tons. Among the largest and the heaviest dinosaur was the Argentinosaurus, a giant of giants about 100 tons in weight. Other giants were Diplodocus which was about 90 feet long with a long slender tail and Brachiosaurus which was 80 feet long and over 40 feet tall and weighed about 50 tons — equal to the weight of about ten elephants, the largest living animal on land.

These reptiles appeared on this planet in the late Carboniferous period (about 300 million years ago) and shared the land with the other amphibians (animals living both in water and on land). They lived together for a fairly long time but the reptiles gradually became more dominant.

Dinosaurs appeared in the Triassic, the earliest period of the Mesozoic era which began about 250 million years ago and lasted about 200 million years. During this period the dinosaurs established their supremacy on the land through competition with the contemporaneous amphibians and ruled the land for about 200 million years. Dinosaurs disappeared from the face of the earth at the close of the Cretaceous period, about 70-65 million years ago. It is thought that the disappearance of the dinosaurs may be a meteoric impact which caused a severe climatic change and brought about their extinction.

Since the nineteenth century dinosaur remains have been found in almost all the continents of the world. This practice is continuous even today and hundreds of dinosaur remains are collected every year. Fossils (remains of the ancient animals) of the oldest dinosaurs have been found in the Triassic rocks which are 230-190 million-years-old rocks and are found in North America, S. Africa and Europe.

Although contemporaneous, they were of different sizes. The size of the North American dinosaur was about 8 feet, while the European and South African dinosaurs were 20 feet long. Among the earlier dinosaurs which appeared in the Jurassic period (190-136 million years ago) were Stegosaurus and Plesiosaurus from North America. Jurassic park in Utah state, USA, is famous because of a Dinosaur quarry. This is one of the world’s greatest concentrations of Dinosaur bones in about 200 million years old rocks. Triceratops, a Cretaceous (136-70 million years old) dinosaur about 25 feet in length, five tons in weight and with three sharp horns on the forehead was discovered in North America and Asia.

During the Mesozoic Era, which comprises Triassic, Jurassic, and Cretaceous periods and covers 200 million years dinosaurs were also common in South America specially in Argentina and Brazil. The Patagonia region, the southern part of Argentina has produced a fair number of dinosaur remains from the Mesozoic Era.

Triceratops and Tyrannosaurus with very short front legs and a long tail have been reported from the cretaceous sediments of Argentina. Argentinosaurus, one of the largest and the heaviest almost weighing a 100 tons have also been found in the late cretaceous period in Argentina. Recently in 2001 the scientists have found the remains of a 40 metres Titanosaurus that weighed almost 70 tons from the “Jurassic Park” in Argentina that tread the earth 70-million-years ago.

Rocks of the Cretaceous period which started about 136 million years ago and ended about 70 million years ago were exposed in parts of Pakistan including Barkhan district of Balochistan province. It was in the year 2000 when the geologists from the Geological Survey of Pakistan during the course of geological mapping of the Barkhan area picked up a fossil bone of a large animal from the upper part of the Pab formation of the Maasstrichtian age about 70-65 million years ago. The discovery was unique, it was the first time that the oldest vertebrate fossil was found in Pab Formation. The bone was tentatively identified as the humerus of a dinosaur.

In order to increase the number of the fossil bones and to ensure the presence of dinosaurs in the area, the Geological Survey of Pakistan in the following year carried out an intensive paleontological survey of the area in collaboration with the University of Michigan, USA and collected around 1500 fossil dinosaurs to the northeast of Vitakri, Barkhan district, Balochistan from the upper Pab Formation. The scientists from the Geological Survey of Pakistan and the University of Michigan have examined and described these fossils and established the occurrence of dinosaurs known as Titanasaurus and a new individual which is named as Pabwehshi in Pakistan during the Cretaceous period.

When compared with the dinosaurs of the same age the Pakistani fossil bones indicate that these bones were related to the dinosaurs from Brazil and Argentina.

With the discovery of the dinosaur fossils, Pakistan entered the list of regions that were inhabited by dinosaurs. Further research may produce more fossil material and give more scientific information specially about the Cretaceous rocks of Pakistan.

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