Steven Spielberg, the renowned Hollywood filmmaker, has aptly portrayed dinosaurs in his 1993 film, Jurassic Park. These reptiles have long been a subject of research for paleontologists, i.e., the people who study fossils, and yet, what we know about them can be best described as the tip of the iceberg.
The term 'dinosaur' was coined by the English paleontologist, Sir Richard Owen in 1842. It is derived from the combination of Greek words 'deinos', meaning something wondrous, powerful, and terrible, and 'saurus', implying a lizard. Tyrannosaurus rex or T. rex is the first thing to come to our mind when we hear the word dinosaur, which, perhaps, has to something do with the depiction of 'dinosaurs' in popular culture. The rex though, was by no means biggest of them all. Talking of 'big' dinosaurs, the species belonging to the Brachiosaurus genus cannot be ignored.
Brachiosaurus inhabited the planet 150 - 160 million years ago, flourishing in the late Jurassic period of the Mesozoic Era (the Age of Reptiles). The genus had some of the tallest and largest known dinosaurs to its credit. These dinosaurs were called arm lizards―nicknamed the 'great arms'―because of their unusually long front feet. Measuring about 85 feet (26 meters) in length and weighing around 33 - 88 tons, they were as tall as a 7-floor building! They walked on all four legs and had a very short tail as compared to their body.
These dinosaurs resembled the giraffes in body structure. Each of their foot had five toes with fleshy pods. They also had claws on both the feet. The large nasal openings at top of their head indicated a well-developed sense of smell. In total, they had 52 teeth: 26 on the upper jaw and 26 on the lower.
Brachiosaurus were purely terrestrial in nature. Earlier it was assumed that they lived in water, but recent studies have proved that it was impossible for them to inhale and inflate their lungs underwater, due to the water pressure at those depths. These dinosaurs lived in groups and often migrated in search of food. They usually laid eggs in linear pattern while walking. They had a lifespan of nearly a hundred years. Their best defense was their huge size and sharp, theropod teeth.
Brachiosaurus were herbivorous in nature. They never chewed their food, but instead, swallowed the entire top of the trees and often the whole tree. They ate a lot―several hundred ounces a day and digested this food in their gut. Owing to their sheer size, they didn't have any predators, which isn't surprising as most other theropods of those times were half the size of Brachiosaurus. These dinosaurs were peace loving creatures.
Due to their massive size, they were a little slow and clumsy. Their size also contributed to problem of high blood pressure in this species. Their brain and head were well above their heart and therefore, they required a strong heart for properly transmit the blood to their head. The blood pressure of a Brachiosaurus was 400 mm, which is nearly 4 times that of humans!
The first fossils of genus Brachiosaurus were discovered in the Grand River Valley in Colorado, USA, in 1900, by the American paleontologist, Elmer S. Riggs. Later in 1909, many fossils were found in Tanzania, Africa, and later, in North America. A huge skeleton of a Brachiosaurus is preserved in 'The Field Museum of Natural History', in Chicago, Illinois. With further research and an improved understanding of the fossils, we will be able to discover some more amazing facts about them.