Brachiosaurus: One of the Largest Dinosaurs

One of the largest dinosaurs of all time, Brachiosaurus could have towered over most four-story modern office buildings today. At first scientists thought the dinosaur weighed 80 tons, but now they’ve lowered the estimate to around 50 tons, which is equivalent to six or so elephants jammed together on a scale. Brachiosaurus remains one of the biggest, tallest, heaviest and longest known sauropods, although its tail was relatively short when compared with others in this group of diverse plant eaters.

Long Neck

The neck of Brachiosaurus could stretch to around 30 feet in length. Twelve individual vertebrae supported its giraffe-like neck, with each vertebral bone measuring 28 inches or more. Paleontologists are stumped as to how a creature with such a gigantic neck could have supplied an even flow of blood to its brain. Without special adaptations, the dinosaur would have fainted all  the time or, even worse, experienced burst blood vessels in the brain when it bent over after raising its tiny head. Scientists theorize that either its heart was extremely powerful, pumping blood at constant high pressure, or the dinosaur kept its head in a position more parallel to the ground, perhaps sweeping it from side to side in search of food.

Feeding and Digestion

Due to its weight, Brachiosaurus would have required approximately 440 pounds of food each day, according to scientific estimates. Since this dinosaur only ate plant materials, it must have spent the majority of its day chewing foliage with its sharp, inwardly curved teeth, gulping the food down its long neck. Gastroliths, otherwise known as "gizzard stones," rested in its gut and helped to further grind down the plant mash.

Long Arms

To support all of the eating action and neck swaying, Brachiosaurus possessed two long "arms." It was the only known dinosaur to have front limbs longer than its hind limbs. Giraffes embody a similar design today, but the front to back difference isn’t as pronounced. The long Brachiosaurus forelimbs allowed the sauropod to raise its chest and shoulder region about 8 feet above ground level. Although this dinosaur likely was not a fast runner, the limbs could have stepped over obstacles with ease and allowed for better access to leaves on tall trees.

Rivals and Defense

Voracious meat eaters like Allosaurus probably preyed upon young or sick Brachiosaurus individuals, but carnivores might have steered clear of adults, due to their intimidating size. Brachiosaurus also possessed sharp claws on its feet that could have gored intruders with one swift kick. Additionally, this dinosaur probably traveled in small herds, gaining protection in numbers.