There are many different kinds and types of dinosaurs, from super small to huge, from peaceful to predatory. The strange ones listed here are mostly lesser known but still having a distinctive characteristic, which makes them unique.
Therizinosaurus
This dinosaur, found in Mongolia, is shrouded in mystery. He was a big one, 10 meters long, but this is not what made him strange. First off, scientists assumed they found a gigantic turtle. Then come his claws, which can be 1 meter long. Imagine that! It is still not certain what he used his claws for. Defending himself? Picking the most delicious plants to eat like a sloth? Or was it a mating call to show he is matured enough? Furthermore it is possible that his body had feathers, although once again solid evidence can't be found. There are just not that many bones to judge from.
Masiakasaurus
He is not a big guy, oh no, this dinosaur is only about 2 meters long and because of its posture he was shorter than a human. What made him unique were his teeth. They were big and bent outwards, looking like hooks. Theory is that he chased small creatures for a living and this peculiar jaw structure allowed him to catch them easily in his mouth. Another interesting thing is his name, Masiakasaurus knopfleri. It comes from the musician Mark Knopfler, whose music inspired the expedition which ultimately discovered this dinosaur.
Sharovipteryx
This is the ancestor of all flying dinosaurs and trust me, it looked hilarious! He was discovered in 1965 in Asia and the most peculiar thing about him was the position of his flying membrane. It was on his ass! Or more accurately, it was surrounding his pelvis, between his back legs and a portion of his tail. Needless to say they couldn't glide for a very long time, it was the only creature known to have his glider like that. Thankfully later dinosaurs evolved in a better direction.
Spinosaurus
Forget about the Tyrannosaurus, this dinosaur was the boss when it comes to carnivores! Estimates (published very recently), showed that the Spinosaurus could reach more than 15 meters in length and his mass was from 7 to 20 tonnes. He was eating both fish and land prey and didn't have any problem going into the water despite his size. His head was crocodile like, which probably helped. His defining characteristic were the extensions on his spine, which grew to at least 1.65 meters. The Spinosaurus was discovered in North Africa in 1915, but the Second World War destroyed what's been found of him. Only recently scientists managed to give us more information about this fearsome beast.
Concavenator
Just another dinosaur, who used to stroll around on his hind legs in what is today's Spain about 130 million years ago. What is so strange about him is the bump on his back, right above his waist. There are different theories regarding it. First, if it was something narrow like a fish fin it means that the hump was used to regulate the temperature of his body. However some scientists argue that the bump was quite fleshy and was used to store body fat, similarly to what camels do. Based on that his pictures can be quite different from one another.
Carnotaurus
The hint is in the name. This dinosaur had horns like a bull. He was built like most other carnivores of his time, big and strong hind legs, small and stinted front limbs. Beside the horns another special characteristics were his deep skull, muscular neck and light body. This leads scientists to believe that this fascinating dinosaurs engaged in fights with each other by ramming their heads, kind of like what bulls do. He was discovered in Argentina and possesses one of the more complete skeletons, which makes it easier to deduce what he looked like.
Pelecanimimus
There exists a special group of dinosaurs, called simply "ostrich dinosaurs" . They are very similar to the big land birds of today. The Pelecanimimus is perhaps the earliest dinosaur from this group. He was about 2.5 meters long , similar to the height of a human. His mouth though, now this is where the nightmares begin. He had 220 teeth in his mouth, specifically designed for cutting and ripping, which later developed into a beak. He also had a crest on his head, so you can imagine him as a huge and very deadly rooster.
Amargasaurus
The Amargasaurus was a herbivore and his size wasn't very significant, he was only about 10 meters long. His bones were discovered in South America. He was related to the Diplodocus, but took a different path, keeping his neck shorter and his body smaller. The special thing about him are the spines, which formed too rows, one on his neck and one on his back. There are different theories regarding them. Some people think they were used to scare predators away, others insist they were used to attract partners. It could be both, of course.
Mononykus
This dinosaur is strange on so many levels. First off, scientists are not 100% sure it was a dinosaur at all, it could be a big running bird. Second, his habitat was the deserts of Mongolia and his big eyes suggest that he might have gone hunting during the night. Third, his forelimbs are extremely small and have just one finger, one claw. It was most likely used to pick up and eat ants and small insects, which is not the behavior displayed by most dinosaurs, considering they were either big predators or big herbivores. Debates about his classification are still going on.
Dilophosaurus
Jurassic Park made this dinosaur famous, although there were a few inaccuracies. He had no neck frills and he didn't spit out poison. That said, he is certainly one of the most recognizable dinosaurs because of the two crests on his head, which resemble half circles. They sat on top of his skull and were most likely bright colored, used for display and finding a partner. He apparently lived in both North America and China regions 200 million years ago. He was a carnivore(especially liking fat guys), 6 meters long and weighting 450 kilograms.
