The Most Bizarre Dinosaurs That Ever Existed

Linhenykus monodactylus is a small dinosaur in a group of species known as alvarezsaurs, whose membership consists of bipedal dinosaurs with absurdly tiny arms. This particularly species inhabited the area which would become Mongolia between 84 and 75 million years ago, and it is unique among the alvarezsaurs. Unlike its close relatives, who all have multiple fingers, linhenykus only has the one, heavily-clawed finger. This makes linhenykus the only known dinosaur to possesses a single finger per arm, a trait which is unusual even to this day.

It is unclear exactly why linhenykus and its relatives had such tiny arms, but there is one theory floating around in the paleontological community. It is hypothesized linhenykus used their thick claws to dig at ants hills and termite mounds to break in and feast on the small insects hiding inside. These creatures were very small, able to fit in the palm of your hand, and could have subsisted on an insectivorous diet.

This scary-looking guy was a small, bird-like dinosaur who lived between 152 and 168 million years ago. Although they sported a primitive form of feathers, they are actually not a direct ancestor to birds. However, epidexipteryx helped scientists better understand some of the transitional stages between dinosaurs and birds. 

Epidexipteryx could not fly, so researchers believe its feathers may have evolved purely as a form ornamentation, perhaps making them more attractive to prospective mates. However, they may not have been stranded on the ground either. Their hands feature several long, narrow fingers that could possibly have been used to climb or extract insects from trees, much like the modern aye-aye. As epidexipteryx is rather small, it would make sense that an arboreal lifestyle would help in keeping them safe from terrestrial threats.

This odd theropod is Concavenator corcovatus, a carnivorous dinosaur that roamed Europe about 130 million years ago. The noticeable hump on its back is unique for these types of dinosaurs, and it has left scientists puzzled since its discovery in 2003. Researchers have thrown out all sorts of theories about the hump, speculating it could be used for mating, storing fat, or maybe that it was purely decorative. Another one of concavenator’s bizarre features are the bumpy protrusions on its arms.

These are similar to the anchor points for modern bird feathers, but scientists believed concavenator most likely had non-scale protrusions that dangled from them. The debate is still ongoing as to the true nature of these strange knobs.

Perhaps one of the most unusual dinosaurs of all, Deinocheirus mirificus was at the heart of a puzzle in the scientific community since 1965. At first, the only fossils recovered from this dinosaur were a pair of massive arms, which measured almost eight feet in length. The arms were originally found in the Gobi desert, but subsequent expeditions to find the rest of its body were fruitless. That is, until two other skeletons were discovered in 2006 and 2009.

At first, researchers were dismayed to hear poachers had stolen and sold off many parts of the skeletons, including a skull. By a stroke of miraculous luck a man named Pascal Godefroit, a representative of the Royal Belgian Institute of Natural Sciences, remembered seeing some of the stolen fossils and was able to point the investigation in the right direction. They discovered that the fossils had been sold to private collectors in Japan and Germany, and were finally able to put an end to a 50 year mystery. 

What scientists learned from the unification of the skeleton was even more shocking than the story of the discovery itself, as Deinocheirus mirificus proved to be one of the most unique dinosaurs in the fossil record. It had a toothless, duck-like bill used to skim water for food, as well as two powerful arms for gathering food and stripping branches from trees. It grew to the size of a tyrannosaurus, and had a massive hump on its back to help its legs support its large body. About 1,400 rocks were found in the belly of one specimen, leading researchers to believe they used them to grind up food in their stomachs, similar to many modern birds. 

Halszkaraptor's skeleton appeared so unusual that at first, experts didn't even think it was real. Andrea Cau, an investigator from the University of Bologna, explains:

"It was so strange that we suspected that it might have been a chimera – a mix of different skeletons glued together. It wouldn’t be the first time."

But once the chunk of rock containing the fossil was scanned, the scientists determined that this creature was for real. It seems to have been amphibious, though its features look more like those of a duck or a swan than a reptile. It presumably ate fish.

Possibly one of the most absurd creatures to ever walk the Earth, incisivosaurus is a buck-toothed dinosaur that lived 128 million years ago. This bird-like dinosaur is unique for it’s bizarre teeth, a rare quality in animals outside of mammals. Most reptiles have one type of tooth, but incisivosaurus had both smaller, sharper teeth, as well as their distinctive front teeth. Some scientists believe they were either herbivorous or omnivorous, another trait that makes them distinct.

Amazingly, their strange physiology helped reveal some major secrets about another type of dinosaur, the oviraptor. It was believed oviraptors may have been birds who had simply lost their ability to fly, but it was later discovered incisivosaurus had actually been an early ancestor to the oviraptors, disproving the theory they came from birds.