Tyrannosaurus Rex

   

Courtesy of: www.kidsdinosaurs.com

    
     Tyrannosaurus Rex, meaning "Tyrant Lizard King", is perhaps the most widely known dinosaur after it's discovery in Hell Creek MT in 1902 by Barnum Brown. Tyrannosaurus was one of the largest land predators of it's time–dating back from 67 mya, to the extinction of dinosaurs 65.5 million years ago. It is still being debated wether or not Tyrannosaurus was an agile predator hunting prey or a lethargic scavenger eating leftovers. After catching it's prey, Tyrannosaurus ripped chunks of flesh and bone. It's teeth were so strong it could grind the animal's bones and swallow them along with the meat.


    Rival Tyrannosaurus probably fought by lunging into each others' necks or heads. Scientists know this due to the discovery of several Tyrannosaurus skulls with bite marks from other Tyrannosaurus. T-Rex was a theropod dinosaur that walked on two legs. Theropod dinosaurs had four toes but only walked on three–the first toe was held above the ground.

Courtesy of: www.dinosaursociety.com

Spinosaurus Aegyptiacus

Spinosaurus Comparison -courtesy of: wikipedia.com

Spinosaurus Aegyptiacus, "spine lizard" was discovered in Egypt in the 1910's and lived in what is now North Africa during the Cretaceous Period.  Spinosaurus is perhaps the largest theropod dinosaur to ever walk the earth at over 40 feet long and 6-20 tons. Spinosaurus was even larger than Tyrannosaurus and Giganotosaurus. Spinosaurus grew more popular after the movie: Jurassic Park 3.  Spinosaurus was most likely a bipedal carnivore which hunted large prey or fished on tidal streams.  Spinosaurus is most widely known for the distinct sail on it's back. This sail may have been used for display or to intimidate rivals. 

The skull of Spinosaurus was similar to modern day crocodiles. This may have enabled Spinosaurus to better catch fish and small aquatic reptiles. The bottom lower of Spinosaurus shows it was also well adapted to hunt larger prey. Therefore, Spinosaurus perhaps is the largest, fiercest, and surely the most awe-inspiring lizard has ever trodden on the Earth.

Artwork courtesy of M. Shiraishi

image courtesy of Professor Paul Olsen