When we think about dinosaurs, it's typically hulking beasts like the fearsome tyrannosaurus rex and the noble triceratops that come to mind. But the era of giant lizards spanned hundreds of millions of years, and for every popular dino that made a cameo in Jurassic Park, there are dozens of little-celebrated, freakishly bizarre creatures with feathers, fingers, and other evolutionary idiosyncrasies. Here, five of the strangest dinosaurs paleontologists have unearthed:
1. The cross between a porcupine and a parrot
The 2-foot-long Pegomastax africanus, a peculiar little beast that lived 200 million years ago, had pig-like fangs, a parrot-like beak, and was covered in porcupine-like quills that made it look like a "strange little bird." Despite its pointy teeth, recent research suggests it subsisted primarily on plants, baring its fangs primarily for self-defense. If the animal were alive, says study author Paul Sereno, "it would be a nice pet — if you could train it not to nip you."
2. The pot-bellied dinosaur covered in feathers
Therizinosaur isn't a household name, says Brian Switek at Smithsonian Magazine. But they are "some of the strangest dinosaurs ever found." The "long-necked, pot-bellied omnivores" possessed unusually long claws, making them more odd than frightening. "The image is wholly different from the dinosaurs I first met as a kid," says Switek. "Perfect for a creature that has pushed the boundaries of what we think a dinosaur is."
3. The cat-sized cross between a mammal and dinosaur
The 20-inch long Thrinaxodon wandered the Woodlands of Africa 250 million years ago, sporting a "cat-like profile" and, quite possibly, fur. It belonged to a group of early Triassic creatures that experts say bridged the gap between dinosaurs and mammals, and could itself have been an ancient ancestor of modern-day mammals.
4. The dinosaur with a finger instead of an arm
T. rex gets made fun of for having short stubby arms, but this bird-like dinosaur is even stranger. It has a single pointy finger where its arm should be. So why did Linhenykus have these seemingly useless extremities? The popular theory is it used these stout digits to feast on insects, digging through bug nests and colonies for its next meal.
5. The dinosaur with a neck twice as long as its body
Consider this massive herbivore the "giraffe of the dinosaur family," says Ki Mae Heussner at ABC News. "Although many think that long necks in animals, including giraffes, are driven by the need to reach food at the tops of high trees," paleontologists suggest neck length could help dinosaurs like Mamenchiasaurus select a mate. Like their spotted, modern-day Doppelgangers, the giraffe-like dinos likely "hugged" by wrapping their necks around each other.