Therizinosaurus

Therizinosaurus

Therizinosaurus was a very weird dinosaur.  It is thought to have had protofeathers.  Its arms were found first.  Those arms had 3 ft or about a meter long claws on each hand.  So paleontologists had assumed they had found a vicious predatory dinosaur.  Its legs, arms, and feet were that of a Theropod.  But the big surprise came when they found the skull.  It was small like the skulls of a long neck Sauropod.  It had blunt teeth for eating plants.  Even so, So if a carniverous Theropod attacked it would be facing 6 swords with unusually long and powerful arms powering the sword.  This dinosaur was a still a Theropod itself.  It was, however, not a predator.   Paleontologists were surprised to see that it was a plant eater.  But it was a big one.  It weighed 5 tons and was 33 feet or 10 meters long.   

One paleontologists said Therizinosaurus looked like a half plucked turkey.  It had a big pot belly for fermenting and digesting plants.  It probably used its large arms and claws to pull branches to its mouth for feeding.  Those arms were over 8 feet or 2.5 meters long.  The 6 long claws really were a formidable set of weapons.  Therizinosaurus probably lived a peaceful life browsing on trees and shrubs, but when threatened it was able to take care of itself.  

There are more than one species of Therozinosaur.  The more primitive ones had claws that were much shorter.  The last or youngest species or most recent species was Therozinosaurus and it had the long sword-like claws that clearly made it able to defend itself.  The ancestor to all Therizinosaurs is thought to be a predatory Theropod carnivore.  This kind of amazing change . . . where a predatory animal eventually evolves into an herbivore is rather rare in nature.