Dinosaurs were a group of cold blooded reptiles that ruled the earth during the Mesozoic Era spanning a period of more than 180 million years making them one of the most successful species to have walked on earth. The Mesozoic period has been divided into three major periods- Triassic, Jurassic and Cretaceous. During the Triassic Period (248 million years to 208 million years) there was one massive supercontinent on earth - Pangea. Dinosaurs had just started to flourish and by the end of this era became a dominant species. Then during the Jurassic Period (208-144 million years) was the peak time of supremacy of the dinosaurs. The dinosaurs got bigger and bigger. The Sauropod dinosaurs (long necked and tailed) began to appear in great numbers. The Amphacilias, the biggest known sauropod is considered to be the largest known creature to have set foot on earth. The supercontinent broke up into two continents - Gondowanaland and Laurasia. During the Cretaceous period (144 - 65 million years) the two continents broke up into the present day forms.And this was the period when dinosaurs saw their dooms day. Though dinosaurs ruled the Cretaceous world too, their end came all of a sudden due to some mysterious reason.                       

       The Theropod group consists of only the Carnivorous dinosaurs where as the remaining groups consists of  only herbivorous dinosaurs. The sauropod dinosaurs included the dinosaurs with long necks, legs and tail with an enormous body. Diplodocus, Argentinosaurus, Brachiosaurus, Giganotaurus, Apatosaurus etc. belonged to this group. The theropod dinosaurs included Tyrannosaurus Rex, Deinonychus, Allosaurus, Compsognathus, Velociraptor etc. The Ornithopod dinosaurs included the Hadrosaurs (duck billed dinosaurs)  too. Miasaurus, Edmontosaurus, Ouranosaurus are worth mentioning. The Stegosaurs and Ankylosaurs were characterized by bony armour on their body and had spikes or heavy club at the tip of their tail. Some of the important dinosaurs of these groups are Stegosaurus, Ankylosaurus, Scelidosaurus, Toujiangosaurus, Nodosaurus, Euplocephalus etc. The Pachycephalosaurus group dinosaurs had a  helmet like bone in its head used for defense. The Ceratopsians were the most unusual looking dinosaurs. They looked more like rhinoceros and head horns on their face and a bony frill around heir neck and a line of bone projecting out of its body running from neck to the tail. The most famous ceratopsians are Triceratops, Protoceratops, Styracosaurus, Brachyceratops.

    During the late Jurassic Period the small and light weight dinosaurs like Deinonychus, Velociraptor, Compsognathus, Dromeosaurus etc. developed feathers and started gliding from tree to tree. Eventually these dinosaurs in later years evolved into first birds which had a well developed tail, claws on the wings, and teeth in their beaks. That is they were not fully birds, and they were no more simple dinosaurs and are regarded as the ancestors of modern day birds. Some of famous avian dinosaurs are Archoepteryx, Sinosauropteryx, Caudipteryx. The Jurassic sky was also ruled by a group of flying reptiles called Pterosaurs viz., Pteroductylus, Ramphorynchus, Quetzacoatlus etc.

      Now the million dollar question is what made  this successful species become extinct. There are many theories which gives us the answer. The most widely accepted theory is that towards the end of Cretaceous period i.e., 65 million years ago an asteroid traveling at a speed of 50000 km/hr hit the earth killing all the living beings on earth. The proof is the crater (of 180 km in diameter) found in Yucatan peninsula in Mexico. This impact initially caused fire burning in North America and then sulphuric acid rain all over the world. It also raised the dust up into atmosphere blocking the sunlight for years. And everything died out. Other theories says that the main reason could be competition from mammals, or a deadly virus broke out, nuclear winter, self declination ( all carnivorous dinosaurs ate up all herbivorous dinosaurs and then they died out due to starvation).

Let me all tell you , how dinosaurs became an obsession for me. I was in the fifth standard, when the movie Jurassic Park was released. I was so much fascinated by the animals that I started collecting the posters and stickers of these creatures and made a small album. I used to collected newspaper articles and cut them and keep them with me. When I was in seventh standard, some Japanese robotics company organized an exhibition in Guwahati, in which they brought their dinosaurs models. These life size models not only made sound but also made some movements (not locomotion). I traveled 180 kms from Tezpur, to visit the exhibition. I bought some books on dinosaurs in the exhibition too. And this was the beginning. I started to gain interest with more and  more knowledge. One month after that, one day when asked, i gave a speech on dinosaurs in the classroom. My friends started to call me the dinosaur boy. I didn't dislike it. I started searching for more books and newspaper articles in the school library. My parents and teachers too helped me and encouraged me.

      When I was in ninth standard, the Discovery channel used to telecast programs named "Paleoworld" and "Bone Head Detectives". I never missed any episode of those. By then I gained so much knowledge regarding Dinosaurs that I decided to pen down a book and finally a manuscript of the book "A Theory On The Mesozoic" was prepared in few months. As I was too young and novice in the field that my father didn't allow me to publish the book. But he assured me that he would allow me to study Paleontology (study of fossils) anywhere in India after 10th board exam. But destiny had something else in store for me. As I was unaware of any Indian University offering that course esp. on Dinosaurs. But still, if I get a chance to go US then I will do a course on dinosaurs or atleast visit the American Museum of Natural History, New York.