Science, Tech, Math › Animals & Nature A Dinosaur ABC for Curious Kids Share Flipboard Email Print Animals & Nature Dinosaurs Basics Paleontologists Carnivores Dinosaurs & Birds Herbivores Marine Reptiles Prehistoric Mammals Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Forestry Evolution View More By Bob Strauss Science Writer B.S., Cornell University Bob Strauss is a science writer and the author of several books, including "The Big Book of What, How and Why" and "A Field Guide to the Dinosaurs of North America." our editorial process Bob Strauss Updated July 03, 2019 01 of 27 A Journey Through the World of Dinosaurs, from A to Z Are you tired of Dinosaur ABC books that feature all the obvious candidates--A is for Allosaurus, B is for Brachiosaurus, and so on? Well, here's an unpredictable ABC that doubles down on some of the more obscure dinosaurs in the prehistoric bestiary, ranging from Anatotitan to Zupaysaurus. All of these dinosaurs really existed, and they all shed some much-needed light on day-to-day existence during the Mesozoic Era. Just click on the arrow at right to get started! 02 of 27 A Is for Anatotitan Anatotitan (Vladimir Nikolov). There's a good explanation for how Anatotitan came by its name, which is Greek for "giant duck." First, this dinosaur was huge, measuring about 40 feet from head to tail and weighing over five tons. And second, Anatotitan had a broad, flat bill on the end of its snout, which it used to dig up plants for its lunch and dinner. Anatotitan was a typical hadrosaur, or duck-billed dinosaur, of North America, where it lived about 70 million years ago. 03 of 27 B Is for Bambiraptor Bambiraptor (Wikimedia Commons). Seventy years ago, the most famous cartoon character on the planet was a cute little deer named Bambi. Bambiraptor was much smaller than its namesake--only about two feet long and five pounds--and it was also much more vicious, a raptor that hunted down and ate other dinosaurs. What's truly amazing about Bambiraptor is that its skeleton was discovered by a 14-year-old boy while hiking in a national park in Montana! 04 of 27 C Is for Cryolophosaurus Cryolophosaurus (Alain Beneteau). The name Cryolophosaurus means "cold-crested lizard"--which refers to the fact that this meat-eating dinosaur lived in Antarctica, and that it had a prominent crest on top of its head. (Cryolophosaurus didn't need to wear a sweater, though--190 million years ago, Antarctica was a lot warmer than it is today!) The fossil specimen of Cryolophosaurus has been nicknamed "Elvisaurus," for its resemblance to the rock-and-roll superstar Elvis Presley. 05 of 27 D Is for Deinocheirus Deinocheirus (Wikimedia Commons). In 1970, paleontologists in Mongolia discovered the enormous, fossilized arms and hands of a previously unknown kind of dinosaur. Deinocheirus--pronounced DIE-no-CARE-us--turns out to have been gentle, plant-munching, a 15-foot-long "bird mimic" dinosaur closely related to Ornithomimus. (Why was so little of Deinocheirus left to discover? The rest of this individual had probably been eaten by an even bigger tyrannosaur!) 06 of 27 E Is for Eotyrannus Eotyrannus (Wikimedia Commons). The tiny Eotyrannus lived 50 million years before more famous relatives like Tyrannosaurus Rex--and at 15 feet long and 500 pounds, it was also much smaller than its famous descendant. In fact, the early Cretaceous Eotyrannus was so slender and lithe, with relatively long arms and legs and grasping hands, that to the untrained eye it might have looked more like a raptor (the giveaway was the lack of single, giant, curved claws on each of its hind feet). 07 of 27 F Is for Falcarius Falcarius (Utah Museum of Natural History)). The weirdest dinosaurs that ever lived were the "therizinosaurs," long-clawed, small-brained, big-bellied plant eaters that were covered in colorful feathers. And Falcarius was the typical therizinosaur, down to its equally weird diet: even though this dinosaur was closely related to meat-eating tyrannosaurs and raptors, it seems to have spent most of its time munching on vegetation (and probably hiding so other creatures wouldn't make fun of it). 08 of 27 G Is for Gastonia Gastonia (North American Museum of Ancient Life). One of the earliest ankylosaurs (armored dinosaurs), the remains of Gastonia were discovered in the same midwestern quarry as those of Utahraptor--the largest, and fiercest, of all the North American raptors. We can’t know for sure, but it's likely that Gastonia figured on this giant raptor's dinner menu, which would explain why it evolved such elaborate back armor and shoulder spikes. 09 of 27 H Is for Hesperonychus Hesperonychus (Nobu Tamura). One of the smallest dinosaurs ever to be discovered in North America, Hesperonychus ("western claw") weighed about five pounds dripping wet. Believe it or not, this tiny, feathered raptor was a close relative of the much bigger (and much more fearsome) Velociraptor and Deinonychus. Another odd thing about Hesperonychus is that it's one of the few pint-sized feathered dinosaurs to be discovered in North America; most of these "dino-birds" hail from Asia. 10 of 27 I Is for Irritator Irritator (Wikimedia Commons). Have your mom or dad ever said they're irritated with you? Well, they probably weren't nearly as irritated as the scientist who was given a skull by a fossil collector, and was so frustrated by the condition he found it in that he named the dinosaur Irritator. For the record, Irritator was a slightly scaled-down South American version of the largest predatory dinosaur of all time, the African Spinosaurus. 11 of 27 J Is for Juratyrant Juratyrant (Nobu Tamura). Until 2012, England didn't have much to boast about in the way of big, vicious, meat-eating dinosaurs. That all changed with the announcement of Juratyrant, a 500-pound tyrannosaur that looked like a vastly scaled-down version of Tyrannosaurus Rex. The fossil of this "Jurassic tyrant" had originally been assigned to another meat-eating dinosaur, Stokesosaurus, until some alert paleontologists set the record straight. 12 of 27 K Is for Kosmoceratops Kosmoceratops (Wikimedia Commons). Do you get upset when your mom tells you to comb your hair (or, worse, does it herself)? Well, imagine how you'd feel if you were a two-ton dinosaur with bizarre "bangs" hanging halfway down your frill. No one knows why Kosmoceratops--a close cousin of Triceratops--had such a distinctive 'do, but it probably had to do something with sexual selection (that is, Kosmoceratops males with bigger frills were more attractive to females). 13 of 27 L Is for Lourinhanosaurus Lourinhanosaurus (Sergey Krasovskiy). The name Lourinhanosaurus sounds vaguely Chinese, but this dinosaur is actually named after the Lourinha fossil formation in Portugal. Lourinhanosaurus is special for two reasons: first, scientists have found stones called "gastroliths" in the fossilized remnants of its stomach, proof that at least some carnivores deliberately swallowed stones to help them digest meals. And second, dozens of unhatched Lourinhanosaurus eggs have been unearthed near this dinosaur's skeleton! 14 of 27 M Is for Muttaburrasaurus Muttaburrasaurus (H. Kyoht Luterman). Complete dinosaur skeletons are extremely rare in Australia, which is better known for its bizarre prehistoric mammals. That's what makes Muttaburrasaurus so special: the bones of this three-ton plant-eater were discovered virtually intact, and scientists know more about its skull than they do about any other ornithopod. Why did Muttaburrasaurus have such a bizarre snout? Probably to clip the leaves off bushes, and also to signal to other dinosaurs with loud honking sounds. 15 of 27 N Is for Nyasasaurus Nyasasaurus (Wikimedia Commons). Scientists have had a hard time figuring out when the first true dinosaurs evolved from their immediate ancestors, the archosaurs ("ruling lizards"). Now, the discovery of Nyasasaurus has pushed that date back to the early Triassic period, over 240 million years ago. Nyasasaurus appears in the fossil record about 10 million years before previous "earliest" dinosaurs like Eoraptor, which means there's a lot we still don't know about dinosaur evolution! 16 of 27 O Is for Oryctodromeus Oryctodromeus (Joao Boto). The small dinosaurs of the Cretaceous period needed a good way to protect themselves against bigger meat-eaters. The solution Oryctodromeus came up with was to dig deep burrows in the forest floor, in which it hid, slept, and laid its eggs. Although Oryctodromeus was a good six feet long, this dinosaur had an extremely flexible tail, which allowed it to curl up into a tight ball until the coast was clear and it could emerge from its burrow. 17 of 27 P Is for Panphagia Camelotia, a close relative of Panphagia (Nobu Tamura). Do you like to help yourself to three or four extra servings of mashed potatoes at dinner? Well, you've got nothing on Panphagia, a 230-million-year-old dinosaur whose name literally translates as "eats everything." It's not that Panphagia was hungrier than the other dinosaurs of the Triassic period; rather, scientists believe this prosauropod may have been omnivorous, meaning it supplemented its vegetable diet with occasional helpings of raw meat. 18 of 27 Q Is for Qiaowanlong Qiaowanlong (Nobu Tamura). One of the biggest North American dinosaurs was Brachiosaurus, which was easily recognized by its long neck and longer front than back legs. Basically, Qiaowanlong (zhow-wan-LONG) was a slightly smaller relative of Brachiosaurus that prowled eastern Asia about 100 million years ago. Like many sauropods, Qiaowanlong isn't well represented in the fossil record, so there's still a lot we don't know about this 35-ton plant eater. 19 of 27 R Is for Rajasaurus Rajasaurus (Dmitry Bogdanov). Only a handful of dinosaurs have been discovered in India, even though this country is home to nearly one-quarter of the world's population. Rajasaurus, the "prince lizard," was closely related to a family of meat-eating dinosaurs that lived in South America during the Cretaceous period. How is this possible? Well, 100 million years ago, India and South America were both joined in the same supercontinent, Gondwana. 20 of 27 S Is for Spinops Spinops (Dmitry Bogdanov). How can you fail to notice a ten-foot-long, two-ton dinosaur with a prominent spike on its snout? Well, that's exactly what happened to Spinops, a close relative of Triceratops whose fossilized bones wound up in a museum drawer for 100 years until they were rediscovered by a team of scientists. This dinosaur's name, Greek for "spiny face," refers not only to that appendage on its snout, but the two dangerous spikes on top of its frill. 21 of 27 T Is for Tethyshadros Tethyshadros (Nobu Tamura). Seventy million years ago, much of modern-day Europe was covered by a shallow body of water called the Tethys Sea. The islands of this sea were populated by various dinosaurs, which evolved to smaller and smaller sizes because they had less food to eat. Only the second dinosaur ever to be discovered in Italy, Tethyshadros was a prime example of this "insular dwarfism," only about a third of the size of its fellow hadrosaurs. 22 of 27 U Is for Unaysaurus Unaysaurus (Joao Boto). Shortly after the first dinosaurs appeared on earth, about 230 million years ago, they started to split off into meat-eating and plant-eating varieties. Unaysaurus, which lived in late Triassic South America, was one of the world's first vegetarian dinosaurs, was technically a prosauropod, and was distantly ancestral to massive plant-munchers like Diplodocus and Brachiosaurus that lived 50 million years later. 23 of 27 V Is for Velafrons Velafrons (University of Maryland). Hadrosaurs, the "duck-billed" dinosaurs, were a bit like the wildebeest in those nature documentaries you always see on TV. Velafrons ("sailed forehead"), like the other duckbills of the late Cretaceous period, spent most of its day either peacefully munching on vegetation or being chased and eaten by smarter, hungrier tyrannosaurs and raptors. As to why Velafrons had such a distinctive crest on its head, that was probably meant to attract the opposite sex. 24 of 27 W Is for Wuerhosaurus Wuerhosaurus (Wikimedia Commons). The most famous spiked, plated dinosaur of all time, Stegosaurus, went extinct by the end of the Jurassic period, 150 million years ago. What makes Wuerhosaurus important is that this close relative of Stegosaurus survived all the way into the middle Cretaceous period, at least 40 million years after its more famous cousin. Wuerhosaurus also had more elaborate plates on its back, which may have been brightly colored to attract the opposite sex. 25 of 27 X Is for Xenotarsosaurus Xenotarsosaurus (Sergey Krasovskiy). There's a lot we still don't know about the two-legged, meat-eating dinosaurs of the Mesozoic Era. A good example is Xenotarsosaurus, a one-ton predator with almost comically short arms. Depending on who you listen to, the South American Xenotarsosaurus was a close cousin of either Carnotaurus or Allosaurus, and there's no doubt that it preyed on the duck-billed dinosaur Secernosaurus. 26 of 27 Y Is for Yutyrannus Yutyrannus (Nobu Tamura). One doesn't normally picture huge, majestic dinosaurs like Tyrannosaurus Rex as having feathers. Yet the family of dinosaurs to which T. Rex belonged, the tyrannosaurs, included some feathered members--the most notable example being Yutyrannus. This Chinese dinosaur lived at least 60 million years before T. Rex, and sported a long, tufty tail that wouldn't have looked out of place on a prehistoric parrot! 27 of 27 Z Is for Zupaysaurus Zupaysaurus (Sergey Krasovskiy). Imagine what it was like to be Zupaysaurus: the last dinosaur left in class after the teacher has taken homeroom attendance, behind even Zalmoxes, Zanabazar and Zuniceratops. There's still a lot we don't know about this 200-million-year-old meat-eater, except that it wasn't very far removed from the first dinosaurs and that it was pretty big for its time and place (about 13 feet long and 500 pounds).