Odd looking: With its bucked teeth, Incisivosaurus would have been a fairly goofy looking dinosaur.

Head-butter: A snarl of spiky horns and knobs, the heavily armoured skull of Dracorex would have made a formidable battering ram.

SYDNEY: Until their sudden demise 65 million years ago, dinosaurs had dominated the Earth for some 165 million years. During this lengthy reign, evolution took them in some weird and wonderful directions. Roll up for our pick of the most bizarre.

GIVEN THE FINGER
Known from a single juvenile specimen found in China, Epidendrosaurus lived some 160 million years ago and sported a hugely elongated third finger. Palaeontologists say this formidable finger allowed the sparrow-sized creature to cling to the branches of trees and probe holes for insects and grubs in the same way as today's aye-aye, a lemur with the same trait. The oversize finger might also have pointed in the same evolutionary direction as the elongated digit of pterosaurs, which supported a membrane that enabled flight.

BUCK-TOOTHED BIRD
Rodent-like teeth on its upper jaw and the beginnings of a beak on its lower jaw gave the metre-long Incisivosaurus one of the weirdest faces around, as pictured at right. Palaeontologists posit that the plant-eating Incisivosaurus was a strange evolutionary intermediate between carnivorous dinosaurs and later forms that lost their teeth and developed full beaks.

BIG BIRD
If Gigantoraptor were around today, this bird-like beast could have peered into a second storey window. Standing five metres tall and weighing in at 1.5 tonnes, the creature is the biggest feathered dinosaur so far discovered. Like modern birds, it had a beak, no teeth and long feather-covered arms. While most large dinosaurs had short, stocky hind limbs, Gigantoraptor had long, chicken-like legs, leading experts to think it was one of the fastest bipedal dinosaurs. Gigantoraptor chased down its prey on the steppes of Mongolia some 85 million years ago.

HEAD-BUTTING DRAGON
A snarl of spiky horns and knobs, this creature's heavily armoured skull probably made a formidable battering ram. The thick, flat forehead and long muzzle would have been great for fending off predators or for clashes over mates. The name Dracorex hogwartsia means 'dragon king of Hogwarts', a reference to the fearsome fire-breathing dragon of Harry Potter's School of Witchcraft and Wizardry. Despite the comparison, however, palaeontologists think the three-metre-long Dracorex – a North American native from 66 million years ago – was probably a relatively peaceful vegetarian.

WADDLING SLOTH
Its close relatives were the infamous carnivores Tyrannosaurus rex and Velociraptor. But palaeontologists describe the 6.5 m Suzhousaurus as more like a waddling sloth. With its bipedal stance and enormous claws, the creature resembled its meat-eating ancestors, but flared ribs and hip bones meant it walked with an awkward, wide-legged gait. According to experts, Suzhousaurus was herbivorous and probably used its claws for gripping branches – or for fending off predators as it waddled between trees in China 115 million years ago.