Therizinosaurus

Therizinosaurus was a species of theropod dinosaurs that lived during the Late Cretaceous Period, around 75 million years ago. Therizinosaurus was one of the last and largest representatives of its unique group, the Therizinosauria.

Appearance
Over 10 meters long and 4.6 meters high, and weighing up to 4 tons, Therizinosaurus lived in Mongolia, Asia.The claws that Therizinosaurus possesed could be as long as 70 cm.-1 m. long and were the biggest known claws of any animal after the less-known Deinocheirus. In fact, when they were first discovered, they were thought to be ribs of a giant tortoise, and were recognized as claws only later.

Behaviour
Therizinosaurus used its long neck to reach higher branches in trees, where it would nibble leaves with its small, beak-like mouth. Also, it could probably hook branches down with its great claws, or use them to strip bark off the tree trunks.

Therizinosaurus was a herbivore despite it being a member of the theropod clan that consisted mainly of carnivorous dinosaurs. When mating or trying to defend its self, Therizinosaurus may have stood with its arms outstretched, like a swan flapping its wings, so that it could display the size of its claws. If this failed, it may have been able to take gentle swipes at any aggressors, although the weight of the claws would have limited their use as an effective weapon.

When walking, Therizinosaurus probably folded its arms against its body, a bit like a bird, to stop the weight of the claws from unbalancing it. With its giant claws, long neck, bulbous body and small head, Therizinosaurus was one of the strangest-looking of all the dinosaurs.

In Chased By Dinosaurs
Nigel searches the early Mongolia deserts and forests for Therizinosaurus, who has massive and very long claws. Nigel catches a scorpion and explains that they have been on the planet long before the dinosaurs, and are still alive today. He also finds a group of Mononykus and discovers they have feathers. The next morning he finds that the Mononykus have eaten his scorpion, and heads out of the denser parts of the forest. There he finds the nesting site of a Therizinosaurus, along with the embryo of one, but also finds herbivore dung around the area. Nigel cannot understand why it is scattered around the nest of Therizinosaurus which he thinks must be a predator.

He speculates that Therizinosaurus used the claws for disemboweling prey, but he gets even more confused as he also finds herbivore teeth amongst the bones. Before Nigel can continue searching, he finds a pack of Velociraptors hunting him. He escapes them by driving them off with a fog horn, and hears some noises by the lake. There, he finds a Tarbosaurus coming down to drink, and while observing it, he finally finds a Therizinosaurus. The two creatures fight each other, with the Tarbosaurus backing down after getting wounded by the huge claws of the Therizinosaurus. After the Tarbosaurus leaves, Nigel is surprised as he finds a whole herd of Therizinosaurus browsing on the trees, which meant that Therizinosaurus is actually a plant-eater that uses its sickle-claws to drag leaves towards its mouth. Nigel attempts to touch one, and he does. He continues observing it using his camera, and at the end, the Therizinosaurus licks Nigel's camera, which makes him fall.