The Cretaceous period saw the earth climate becoming much more humid which were ideal for plants. It is not surprising the most of the dinosaurs in the Cretaceous period were plant eaters. The Cretaceous period also saw a swing in evolution, the gigantic dinosaurs gave way to smaller creatures. Although the giants and hunter dinosaurs were still the dominants habitant of the Cretaceous world.

Tarbosaurus a habitant of the Cretaceous world was a terrifying hunter, measuring 10 metre long and was one of the fiercest dinosaurs ever lived. It lives a solitude existence. Another flesh eating dinosaurs that lived at the same time of the Tarbosaurus was the infamous Velociraptor (a central character in the movie JURRASIC PARK) . Smaller than the Tarbosaurus, Velociraptor was still one of the most vicious and deadly killer that roamed the Cretaceous world. Measuring only 2.8 metre long and 1.5 metre high, any creature chased by these ‘speedy predator’ will had no chance of escape. Even the fearsome Tarbosaurus had no chance against Velociraptor assault. With its sharp sickle-like claws, 38 centimetre in length, this predator can easily rip-off its prey. Velociraptors are found mostly in Mongolia which also house small plant eating dinosaurs such as Protoceratops, Microceratop and Pinacosaurus.

The early Cretaceous Period also seems to be a heaven for the plant eaters. With more variety of plants flourishing the pre-historic world, newer breed of dinosaurs starts to appear. Most were plant eaters , but there were also some vicious meat eater. Some of the plant eaters of this period had armour for defence. Polacanthus was protected by sharp spines and bony plates on its back. Hyleosaurus, measuring 6 metre long, had armour plates with spines at the end of its tail.. These plant eaters seems to roam the pre-historic land of south Africa and north America. During the early Cretaceous period, there were also some strange carnivores like the Baryonix. It had an unusual crocodile-like head and equipped with 30 centimetre long curved claws that scientist thought to be its weapon and is also used to catch fish. It lived in the southern part of England and Belgium which is the same area of the mighty Iguanodon.

The Iguanodon was an enormous plant eater measuring 10 metre long and stood 6 metre high. This mighty herbivores had a thumb spike on each hand that it used for defence. Muttaburrasaurus a relative of the Iguanodon lived at Australia. This rare Australian dinosaur was one of the few dinosaurs that were found in Australia . And of all dinosaur skeletons discovered in Australia, the Muttaburasaurus is the most complete. Muttaburasaurus had a toothless beak for nipping off shoots. It had had teeth at the sides of its beak which were better suited to cutting and slicing than the Iguanodon grinding teeth. It is possible that Muttaburasaurus had to cope with different type of vegetation than its more northerly relation.

In Montana USA, palaeontologist had discovered one extraordinary skeleton of a big tail dinosaurs. They called this dinosaur Tenontosaurus which mean sinew lizard and had a huge powerful tail to protect itself from attacks by fierce predator such as Deinonychus. Deinonychus belongs to same family of the Mongolian speedy predator, Velociraptor.

In north America and south Africa, lived one of the earliest species of ‘duck billed’ dinosaurs. Ourannosaurus was quite different from its later descendent. Ourannosaurus had a remarkable sail on its back consist of skin stretched over long spines that grow from it back bone. Scientists thought that the sail was filled with blood vessel that will help them warmed up. Once this harmless plant eater had warmed up, it can move more quickly. Scientists also believed that the sail also helped the Ourannosaurus to cool down. When there were breeze it stood with it sail sideways on the wind which helped to lower its body temperature. As it cooled the sail sent out heat like a giant radiator. Ourannosaurus will not become overheated, even on the hottest day. Another sail-backed dinosaurs that lived at the same time with Ourannosaurus was Spinosaurus. But unlike the gentle plant eater Ourannosaurus, Spinosaurus was a deadly flesh eater. It measured 12 metre long. Some scientists think that Spinosaurus sail may have been brightly coloured which it used as a warning to threaten the other male. Spinosaurus also used its sail to attract a mate during the breeding season. When Spinosaurus was first discovered in Egypt, only a few bone were unearthed. These included a broken lower jaw, some teeth and a few backbones. Sadly, this important evidence was destroyed by bombs dropped on Dresden, Germany , in Second World War. Spinosaurus lived at about same time and same place with some other Spinosaurid (Spinosaurid are a family of meat eating dinosaurs with tall spines along their backs which supported a sail of skin) such as Altispinax and Metriacanthosaurus.

The bird mimic dinosaurs were also found during this period. The Avimimus, said to have feathers along their arms and at the end of the arms were sharp claws which is probably used to slashed out at smaller prey. The Hadrosaurs were also the inhabitant of the Cretaceous world, the Secrenosaurus, Parasauroluphus, Prosaurolophus and Lambeosaurus are hadrosaurs that thrived the Cretaceous. Fierce dinosaurs hunt these gentle herbivores and these herbivores normally fall easy prey to the likes of Albertosaurus and Daspletosaurus, both hunters belongs to the tyranosaurid. They were the most terrifying dinosaurs at that time, measuring about 6 metre and 10 metre long. In Utah, USA lived another species of dinosaur that was related to the Velociraptor called Utahraptor. The Utahraptor was a great survivor as it roamed the earth until the end of the dinosaur era.

The late cretaceous period which lasted from 80 to 66 MYA was a time of great change. The continent that we know today were gradually taking shape. During this time many flowering plant burst into bloom. Roses and primroses turned their head to the sun, dazzling water lilies floated on the surface of lake. Evergreen pines were shooting upwards. Trees that shed their leaves started to appear, growing along side breadfruit, fig and palm trees that now only grow in the warm part of the world. One of the most common and famous dinosaurs at that time was the Triceratop. The Triceratop is a large, powerful dinosaurs with a stumpy horn on its nose and one above each eye which measured 1 metre long . It probably used its horn to protect itself from predators. Around its neck was a huge bony frill which protected it shoulder from other dinosaurs. Triceratops feeds on shoots and leaves using its bony parrot-like beak. Triceratops could charge at its enemies by sprinting at top speed that scientists calculate at 30 km/hours. A charge from rhinoceros like dinosaurs would been enough to scared off many predators.

Another famous dinosaurs from the late Cretaceous period was Ankylosaurus, one of the last and largest armoured dinosaur. This gigantic Ankylosaurus was almost as well protected as a military tank that only big an fierce carnivores would have threatened this plant eater. Liked the other Ankylosaurid, Ankylosaurus has an extra protection at the end of its long tail (a large boney club as big as a large suitcase). Pachycephalosaurus was another famous cretaceous dinosaurs. This dinaosaur had a thick boney skull which it probably use to protect its brain when battling other Pachycephalosaurus during the mating seasons. These dinosaurs will charged and smashed their head with each other during the battle. Its thick boney skull is not useful for defending themselves from predators. The Cretaceous period also sees the largest dinosaur on the planet earth. The earth shaking Seismosaurus, a sauropod measured 52 metre long and weigh about the same as 19 african elephants.

The largest predator during the late cretaceous period is probably the Tyrannosaurus Rex measuring 14 metre long and 6 metre high. It had backward pointing teeth that measures 30 cm long each and a big head about 2 metre long. But these dinosaurs had very small forearms that can’t even reach their mouth. Scientists are still guessing on the uses of these arms. Another predator is the Dromeosaurus, a relative of the velociraptor from mongolia measure 2 metre long and 1 metre high. This dinosaur was as fierce as its relative. The dinosaurs were very great survivors but why did they became extinct. They had dominated the pre-historic world for 1600 million years. Then they vanished surprisingly quickly. Expert have puzzled over this for many years but still no plausible explanation as to why dinosaur become extinct with some other pre-historic animal.