If anyone ever challenges you to name an animal that's as awkward as it is terrifying, calmly reply, "duh, the Therizinosaurus." This late Cretaceous therapod was several meters tall and sported 40-inch claws, the biggest of any animal ever. It also had a weird pot belly, a snubbed tail, and a beaky face: behold, the strangest Frankenstein monster in existence. It's so bizarre that at first, paleontologists didn't even believe its fossils belonged together. Artwork by IsisMasshiro.
The Balaur, a small raptor first discovered in 2010, is a prime example of the evolutionary "island effect." Isolated on an island, the Balaur evolved away from its more famous cousin, the Velociraptor. It developed two giant foot claws instead of one, a low center of gravity, and bulky, muscular legs. It was essentially a beefed up version of a regular raptor, and specialized in kicking prey much larger than itself to the ground like some kind of Mesozoic ninja. Artwork by NTamura.
Whoa, check out that freaky smile! Masiakasaurus knopfleri is easily the top runner for Dinosaur Most in Need of Braces. Paleontologists think its bizarre set of outwardly pointing teeth evolved so the Masiakasaur could spear fish with its face (quite the party trick!). Also, fun fact: this dinosaur was named after Dire Straights frontman Mark Knopfler, whose music was playing as its skeleton was unearthed. Artwork by HodariNundu.
The Guanlong was one of the earliest tyrannosaurs ever discovered, and also one of the most stylish. Seriously, check out that chic head crest! Too thin and fragile to be a weapon, the crest was likely a built-in personal ad for attracting lonely lady Guanlongs. The discovery that such a strange ornament adorned the granddaddy of T-Rex revealed that there is much to be learned about tyrannosaur diversity. Artwork by HodariNundu.
Spinosaurus was the main villain of Jurassic Park III because...well, look at this terrifying beast! It's the biggest meat-eating dinosaur ever found, much larger than T-Rex. What makes this enormous carnivore even more intimidating is its freaky appearance: a crocodilian head, dextrous arms, and a dramatic sail that serves no obvious purpose except to say, "Enjoy the view, it's going to be your last!"
Pegomastax was only identified in the last few months, bringing a whole new world of weird into paleontology. Its mouth looks like a Medieval torture device, and paleontologists think its canine teeth sharpened themselves against each other. As if that's not weird enough, Pegomastax likely sported quills all over its body. Though it was about the size of a house cat, we sure wouldn't want to pet one. Artwork by Teratophoneus.
The few dinosaurs who managed to survive the KT extinction event gradually evolved into modern day birds. But the Oviraptor here must've been too impatient to wait 65 million years, as it apparently tried to bridge the gap all by itself. With its avian head, feathered arms, and a proven compulsion to incubate eggs in nests, Oviraptor is just a Cretaceous riff on an ostrich...and looks it too. Artwork by Apsaravis.
Brachiosaurus and Apatosaurus are probably the most famous sauropods, or "long necks," of the Mesozoic Era. But Mamenchisaurus deserves some love for taking neck length to the extreme. This dinosaur evolved the most ridiculously extended neck of any sauropod, about 35-40 feet. In fact, the Mamenchisaurus' neck was so freaking huge that it couldn't hold its head in the tree tops (you try pumping blood 40 feet high!) but rather swept its mouth through underbrush like the world's weirdest-looking vacuum cleaner. Artwork by AshiRox.
The predators eyeing the Tuojiangosaur in this image are cautious, and for good reason. While this member of the stegosaur was undoubtedly delicious, it evolved a badass pair of shoulder spikes to fend off attackers. Unlike its cousin stegosaurs, the Tuojiangosaurus made it virtually impossible for predators to get in a bite at its precious neck without skewering themselves. Artwork by Alexandernevsky.
Now, I'm all for dinosaurs having high self esteem. But there's no way around it: Carnotaurus was one ugly lizard. We're talking bony horns over its eyes, a stocky build, and arms so puny they make T-Rex's look like a boxer. But what Carnotaurus lacked in the looks department, it made up for in badassery. The muscular build suggests this dinosaur was a real sprinter, and its arms probably shrunk because it attacked its prey with its tough head and neck, like a bull. So if you run into one, laugh it up, but know that it's your last laugh. Artwork by
Pterosaurs are not technically dinosaurs, but we had to make an exception to show off the bizarre Sharovipteryx. This Triassic reptile evolved wing flaps on its hind limbs instead of its front, and likely fed on insects while gliding between trees. Though bizarre in design, you have to admit this pint-sized flyer is pretty darn cute too. Artwork by NTamura.
We had to save our favorite for last. Thought the Oviraptor was weird? Well, nature decided to outdo herself and make one in Extra Large: the Gigantoraptor. Just look at this insane animal! It was 16 feet tall, weighted 2 tons, and likely sported colorful feathers. Paleontologists remain flummoxed by how it moved and what it ate: the lack of sharp teeth suggest vegetation was on the menu, but then why the enormous claws? Whatever it dined on, Gigantoraptor was easily the Biggest Bird of all time. Artwork by NTamura.