There is an amazing array of dinosaur shapes and sizes. The different shapes and sizes of dinosaurs evolved to suit the way in which the animals lived.
Tiny, agile Compsognathus lived on small animals and could move fast enough to catch them. Allosaurus was a huge, fierce and muscular dinosaur; while long necked Diplodocus could reach the leaves that most other dinosaurs could not reach.
Gigantic And Slow
Diplodocus (di-plod-o-cus) had a very long neck and tail and reached 27m in length. It had a slender body and a tiny head for its size. Diplodocus needed to eat vast amounts of food to survive and had a huge stomach to digest all the leaves.
Diplodocus tiny head was held at an angle to the neck. It had weak jaws with thin peg-like teeth to comb vegetation into its mouth.
It’s powerful neck muscles lift the head up and down. It had large and strong shoulders and forelimbs. Its neck connected to a strong backbone to prevent its massive body from collapsing. It had pillar like legs as thick as tree trunks, and five toes like an elephants foot. The first toe was large and sharap.
Tiny And Fast
Compsognathus (comp-sog-nay-thus) is one of the smallest dinosaurs to be discovered so far, about the size of a chicken and walked upright on 2 legs. It was a meat-eater, but it was light and could run very fast. It was a clever predator, which chased after, and fed on, lizards and insects.
Compsognathus had a long tail almost half the length of its body that it used for balance. It had long boned back legs for speed, and short arms and hands for front legs. It had a slender head with over 60 curved shaped teeth.
Large And Muscular
Dragon-like Allosaurus (al-oh-saw-rus) was a fierce meat-eater. It was strongly built so that it could attack and kill. It could not run fast for long distances, but probably caught smaller, younger or slow dinosaurs, or ate carrion (animals that are already dead).
It was about the size of a giraffe and walked upright on its two hind legs. It’s front legs were short stubby arms with 3-fingered hands. This gave them a strong grip and allowed them to tear into prey.
It had a thick short neck and a strong back to support it’s heavy body. Its wide hinged mouth had huge jaws and 60 dagger-like teeth.
Four Fingered And Beaked
Psittacosaurus (si-tak-oh-saw-rus) was given a name that means “parrot-reptile” because it had a sharp, horny beak at the front of its mouth for slicing through plants. Psittacosaurus is a ceratopian.
This dinosaur had long back legs but shorter arms, with four long fingers. It may have walked on all-fours at times. It was almost as tall as a man, with long clawed fingers to grab food and balance on all fours.
Large And Thick Headed
Pachycephalosaurus (pak-ee-kef-al-ohsaw-rus) had a skull with a very thick top, decorated with knobs and spikes. It may have used these as weapons for head-butting fights with other members of its species. It was a large dinosaur, about the size of an elephant, that walked upright, and used its tail to balance on when resting.
Horned And Spiked
Styracosaurus (Sty-rak-oh-saw-rus) had a large horn on its nose, and a spiky frill around its neck. These were probably used to warn off enemies and rivals, and to attract mates. This plant eating dinosaur was a ceratopian and was related to Triceratops. Its name means “spiked reptile”.
What Is A Ceratopian
Ceratopians were herbivores. Many looked like rhinoceroses, with sturdy bodies and horned faces. However, ceratopians had curved beaks at the front of their jaws. They lived in the Cretaceous Period, and have been found in North America and Asia. They included Triceratops, tyracosaurus and Psittacosaurus.
Head Butting
Some dinosaurs clashed in head-to-head battles like today’s mountain sheep. This head-butting took place among males. It was a test of strength to see which would lead the herd or win a mate. The brains of dinosaurs like Pachycephalosaurus were quite small and were protected from head blows by very thick bone on the top of the skull.