Dinosaurs

Dinosaurs: (in alphabetical order with small description)

Adasaurus This raptor's hind claws were unusually small.

Adeopapposaurus A close relative of Massospondylus.

Aegyptosaurus Guess what country this dinosaur was found in?

Aeolosaurus Could this titanosaur have reared up on its hind legs?

Aerosteon This air-boned dinosaur may have breathed like a bird.

Afrovenator One of the few carnivores ever to be dug up in northern Africa.

Agilisaurus This "agile lizard" was one of the earliest ornithopods.

Agustinia A large, spiny-backed sauropod.

Alamosaurus No, it wasn't named after the Alamo, but it should have been.

Alaskacephale Guess what state this pachycephalosaur was found in?

Albertonykus A tiny, birdlike, North American dinosaur.

Allosaurus One of the most common predators of the Jurassic era.

Altirhinus This "high-nosed" plant eater resembled an early hadrosaur.

Alvarezsaurus A bird-like dinosaur of the late Cretaceous.

Alxasaurus An early relative of the bizarre Therizinosaurus.

Amargasaurus A bizarre, spined sauropod from South America.

Amazonsaurus One of the few dinosaurs to be found in the Amazon basin.

Ammosaurus This may (or may not) have been the same dinosaur as Anchisaurus.

Ampelosaurus One of the best-known of the armored titanosaurs.

Amphicoelias Could it have been the biggest dinosaur that ever lived?

Amurosaurus The most complete hadrosaur to be discovered in Russia.

Anabisetia The best-attested South American ornithopod.

Anatosaurus This dinosaur is now known as either Anatotitan or Edmontosaurus.

Anatotitan This hadrosaur's name means "giant duck."

Anchiornis A four-winged dino-bird that resembled Microraptor.

Anchisaurus One of the first dinosaurs ever to be dug up in the U.S.

Andesaurus This titanosaur rivaled Argentinosaurus in size.

Angaturama A Brazilian relative of Spinosaurus.

Angolatitan The first dinosaur ever to be discovered in Angola.

Angulomastacator This dinosaur had a strangely shaped upper jaw.

Animantarx This "living fortress" was discovered in an unusual way.

Ankylosaurus The Cretaceous equivalent of a Sherman tank.

Anserimimus This "goose mimic" didn't bear much of a resemblance.

Antarctopelta The first dinosaur fossil ever discovered in Antarctica.

Antarctosaurus This titanosaur may or may not have lived in Antarctica.

Antetonitrus Either a very late prosauropod, or a very early sauropod.

Apatosaurus The dinosaur formerly known as Brontosaurus.

Appalachiosaurus One of the few dinosaurs ever to be found in Alabama.

Aragosaurus Named after the Aragon region of Spain.

Aralosaurus Not much is known about this central Asian duckbill.

Archaeoceratops Possibly the smallest ceratopsian that ever lived.

Archaeopteryx This ancient, flying reptile was about the size of a modern pigeon.

Archaeornithomimus A likely ancestor of Ornithomimus.

Argentinosaurus Possibly the largest dinosaur that ever lived.

Argyrosaurus A plus-sized titanosaur from South America.

Aristosuchus This "noble crocodile" was actually a dinosaur.

Arrhinoceratops This ceratopsian was named for its "missing" nose horn.

Astrodon The official state dinosaur of Maryland.

Atlasaurus This sauropod had unusually long legs.

Atlascopcosaurus Named after a manufacturer of digging equipment.

Atrociraptor This "cruel thief" wasn't as atrocious as its name implies.

Aublysodon This tyrannosaur was named after a single tooth.

Aucasaurus This predator was a close relative of Carnotaurus.

Auroraceratops A close relative of Archaeoceratops.

Australodocus This sauropod was found in modern-day Tanzania.

Australovenator A brand-new carnivore from Australia.

Austroraptor The largest raptor from South America.

Austrosaurus This titanosaur was discovered near a train station.

Avaceratops This ceratopsian is represented by a single juvenile.

Aviatyrannis This "grandmother tyrant" was one of the first tyrannosaurs.

Avimimus A particularly bird-like cousin of Oviraptor.

Bactrosaurus One of the earliest of the duck-billed dinosaurs.

Bagaceratops A small ceratopsian from central Asia.

Bagaraatan No one is quite sure how to classify this theropod.

Bahariasaurus This obscure carnivore may have been the size of T. Rex.

Balaur This "stocky dragon" was recently discovered in Romania.

Bambiraptor Yes, this tiny raptor was named after you-know-who.

Barapasaurus Probably the first of the giant sauropods.

Barosaurus An enormous plant-eater with a tiny head.

Baryonyx You wouldn't want to clip this dinosaur's claws.

Becklespinax A strangely named theropod of the early Cretaceous period.

Beipiaosaurus The only known feathered therizinosaur.

Beishanlong This bird mimic weighed over half a ton.

Bellusaurus A herd of this sauropod drowned in a flash flood.

Bistahieversor This tyrannosaur had more teeth than T. Rex.

Bonitasaura This titanosaur wasn't as beautiful as its name implies.

Borogovia This theropod was named after a Lewis Carroll poem.

Bothriospondylus A case study in dinosaur confusion.

Brachiosaurus A giant, gentle, long-necked plant-eater.

Brachyceratops A little-known ceratopsian from North America.

Brachylophosaurus This duck-billed dinosaur's beak looked more like a parrot's.

Brachytrachelopan This sauropod had an unusually short neck.

Brontomerus Its name is Greek for "thunder thighs."

Bruhathkayosaurus Was this titanosaur bigger than Argentinosaurus?

Buitreraptor The oldest raptor ever discovered in South America.

Byronosaurus This theropod was a close relative of Troodon.

Camarasaurus The most common sauropod of Jurassic North America.

Camelotia An early member of the line that evolved into sauropods.

Camptosaurus A close relative of Iguanodon.

Carcharodontosaurus Its name means "great white shark lizard." Impressed yet?

Carnotaurus The shortest arms of any meat-eater--and horns to match.

Caudipteryx A birdlike dinosaur that changed the views of paleontologists.

Centrosaurus Like a unicorn, this ceratopsian only had one horn.

Cerasinops A small ceratopsian of the late Cretaceous.

Ceratonykus This dino-bird was discovered in Mongolia in 2009.

Ceratosaurus This primitive carnivore is hard to classify.

Cetiosauriscus Not to be confused with the more famous Cetiosaurus.

Cetiosaurus Guess which creature this "whale lizard" was once mistaken for?

Chaoyangsaurus An early ceratopsian of the late Jurassic period.

Charonosaurus This duck-billed dinosaur was much bigger than an elephant.

Chasmosaurus The only dinosaur that came with its own awning.

Chialingosaurus One of the earliest Asian stegosaurs.

Chilantaisaurus This large theropod may have been ancestral to Spinosaurus.

Chindesaurus This early dinosaur was a close relative of Herrerasaurus.

Chirostenotes This birdlike dinosaur has been known by three different names.

Chubutisaurus This titanosaur was on Tyrannotitan's lunch menu.

Chungkingosaurus This early stegosaur had some primitive characteristics.

Citipati This Mongolian theropod was a close relative of Oviraptor.

Claosaurus This "broken lizard" was a primitive hadrosaur.

Coahuilaceratops It had the longest horns of any known ceratopsian dinosaur.

Coelophysis One of the most ancient dinosaurs ever to roam the earth.

Coelurus This tiny dinosaur was a close relative of Compsognathus.

Colepiocephale This thick-skulled dinosaur's name is Greek for "knucklehead."

Compsognathus The size of a chicken, but much meaner.

Concavenator This large theropod had a bizarre hump on its back.

Conchoraptor This "conch thief" may have lunched on mollusks.

Condorraptor A small theropod of middle Jurassic South America.

Corythosaurus This "Corinthian-helmeted" dino had a distinctive mating call.

Crichtonsaurus This dinosaur was named after the author of Jurassic Park.

Cryolophosaurus This crested carnivore was once known as "Elvisaurus."

Cryptovolans Was this the same dinosaur as Microraptor?

Diamantinasaurus This titanosaur was recently discovered in Australia.

Diceratops Was this two-horned dinosaur really a specimen of Triceratops?

Dicraeosaurus A medium-sized, spiny-necked sauropod.

Dilong This "emperor dragon" may have been an ancestor of T. Rex.

Dilophosaurus This dino was distinguished by the bony crests on its noggin.

Dimetrodon This ancient synapsid had a huge sail on its back.

Diplodocus "Thin at one end, much thicker in the middle, and thin again at the far end."

Dollodon Named after the Belgian paleontologist Louis Dollo.

Dracopelta This early ankylosaur was discovered in Portugal.

Dracorex The only dinosaur to be named after the Harry Potter books.

Dravidosaurus This "dinosaur" may actually have been a marine reptile.

Drinker Named after the famous paleontologist Edward Drinker Cope.

Dromaeosaurus This "running lizard" was probably covered with feathers.

Dromiceiomimus Possibly the fastest dinosaur that ever lived.

Dryosaurus A typical ornithopod of the late Jurassic.

Dryptosaurus The first tyrannosaur to be discovered in the U.S.

Dubreuillosaurus This megalosaur had a long, low snout.

Dyslocosaurus Its name means "hard-to-place lizard."

Dystrophaeus This Diplodocus-like sauropod was named by Edward Cope.

Echinodon One of the few ornithopods to sport a set of canines.

Edmarka This may have been a species of Torvosaurus.

Edmontonia This armored dinosaur never actually lived in Edmonton.

Edmontosaurus This large, duck-billed herbivore was a contemporary of T. Rex.

Efraasia This Triassic herbivore may have been ancestral to sauropods.

Einiosaurus This ceratopsian was a close relative of Centrosaurus.

Ekrixinatosaurus Its name means "explosion-born lizard."

Elaphrosaurus A lightweight theropod from the late Jurassic.

Elrhazosaurus Once classified as a species of Valdosaurus.

Enigmosaurus This "puzzle lizard" was closely related to Therizinosaurus.

Eocarcharia This "dawn shark" prowled the woodlands of northern Africa.

Eocursor This late Triassic reptile was one of the earliest true dinosaurs.

Eodromaeus Yet another ancient theropod from South America.

Eolambia An early hadrosaur from North America.

Eoraptor This tiny dinosaur was among the first of its kind.

Eotyrannus This early tyrannosaur looked more like a raptor.

Epachthosaurus This "heavy lizard" was relatively primitive for its time and place.

Epidendrosaurus Did this tiny dino-bird spend its life up a tree?

Equiijubus Its name is Greek for "horse mane."

Erketu This titanosaur had an unusually long neck.

Erlikosaurus This late therizinosaur roamed the Mongolian forests.

Euhelopus The first sauropod to be discovered in China.

Euoplocephalus Even this ankylosaur's eyelids were armored.

Europasaurus The smallest sauropod ever discovered.

Euskelosaurus The first dinosaur ever to be discovered in Africa.

Eustreptospondylus A close cousin of Megalosaurus.

Fabrosaurus This early ornithopod may have been a species of Lesothosaurus.

Falcarius A bizarre, feathered theropod from North America.

Fruitadens One of the tiniest dinosaurs ever to live in North America.

Fukuiraptor One of the few carnivorous dinosaurs ever to be dug up in Japan.

Fukuisaurus This ornithopod was discovered in Japan.

Fulgurotherium Very little is known about this "lightning beast."

Futalognkosaurus A very big, and very strangely named, sauropod.

Gallimimus This "chicken mimic" roamed the plains of the late Cretaceous.

Gargoyleosaurus This "gargoyle lizard" was an ancestor of Ankylosaurus.

Garudimimus A relative slowpoke compared to other ornithomimids.

Gasosaurus Yes, that's its real name, and no, it isn't for the reason you think.

Gasparinisaura One of the few ornithopods known to have lived in South America.

Gastonia This ankylosaur was probably on Utahraptor's lunch menu.

Giganotosaurus Not quite a "Gigantosaurus," but close enough.

Gigantoraptor This huge oviraptor weighed over two tons.

Gigantspinosaurus It may or may not have been a true stegosaur.

Gilmoreosaurus One of the few dinosaurs known to have suffered from cancer.

Giraffatitan Might this "giant giraffe" have been a species of Brachiosaurus?

Gobiceratops This ceratopsian's tiny skull was found in the Gobi Desert.

Gojirasaurus This early predator was named after Godzilla.

Gondwanatitan Yet another titanosaur from South America.

Gorgosaurus Might this tyrannosaur have been a species of Albertosaurus?

Goyocephale A primitive bonehead from Asia.

Gryposaurus One of the most common of the duck-billed dinosaurs.

Guanlong Probably the first tyrannosaur ever to walk the earth.

Hadrosaurus The official state dinosaur of New Jersey.

Hagryphus The largest North American oviraptor yet discovered.

Haplocanthosaurus A typical sauropod of the late Jurassic.

Haplocheirus This feathered dinosaur predated Archeopteryx by millions of years.

Harpymimus Named after the winged creature of Greek myth.

Herrerasaurus This carnivore roamed present-day South America.

Hesperonychus A tiny North American dinosaur.

Hesperosaurus The oldest stegosaur discovered in North America.

Heterodontosaurus This "different-toothed" dinosaur was a dentist's nightmare.

Hexinlusaurus Named after the Chinese professor He Xin-Lu.

Heyuannia Yet another close relative of Oviraptor.

Hippodraco This "horse dragon" was recently discovered in Utah.

Homalocephale This herbivore had a very flat--and very thick--skull.

Hongshanosaurus This early ceratopsian is known by two skulls.

Huabeisaurus A titanosaur from northern China.

Huaxiagnathus One of the biggest dino-birds of its time.

Huayangosaurus Could this have been the ancestor of all the stegosaurs?

Hylaeosaurus One of the first creatures ever to be called a dinosaur.

Hypacrosaurus We know a lot about this dinosaur's family life.

Hypselosaurus This titanosaur's eggs were a foot in diameter.

Hypsilophodon This man-sized herbivore liked to eat and run.

Ignavusaurus Its name means "cowardly lizard."

Iguanacolossus A brand-new ornithopod from North America.

Iguanodon The second dinosaur in history ever to receive a name.

Ilokelesia A primitive abelisaur from South America.

Incisivosaurus This buck-toothed dinosaur was the Cretaceous equivalent of a beaver.

Indosuchus This "Indian crocodile" was actually a dinosaur.

Ingenia A small, birdlike dinosaur from central Asia.

Irritator This spinosaur was named by a very frustrated paleontologist.

Isisaurus Otherwise known as the Indian Statistical Institute Lizard.

Janenschia The earliest titanosaur in the fossil record.

Jaxartosaurus A poorly known hadrosaur from central Asia.

Jeholosaurus This ornithopod may have had an omnivorous diet.

Jeyawati Its name is Zuni for "grinding mouth."

Jinfengopteryx This feathered dinosaur was once thought to be a true bird.

Jingshanosaurus A close relative of Yunnanosaurus.

Jinzhousaurus This Asian dinosaur was one of the first hadrosaurs.

Jobaria A strange, short-tailed African sauropod.

Juravenator Why didn't this presumed "dino-bird" have feathers?

Kaijiangosaurus This might have been the same dinosaur as Gasosaurus.

Kentrosaurus A smaller, African cousin of Stegosaurus.

Khaan Few small mammals dared face the wrath of this dinosaur.

Kileskus Yet another "basal" tyrannosaur from central Asia.

Kol It's tied with Mei for "shortest dinosaur name."

Koreaceratops Did this ceratopsian like to go swimming?

Kosmoceratops This ceratopsian had a bizarre, downward-folding frill.

Kotasaurus One of the few sauropods to be discovered in India.

Kritosaurus A famous, but poorly understood, hadrosaur.

Kryptops This dinosaur came equipped with its own face mask.

Labocania It may or may not have been a true tyrannosaur.

Lagosuchus Could this have been the ancestor of all the dinosaurs?

Lambeosaurus This herbivore had a hatchet-shaped crest on its noggin.

Lanzhousaurus This herbivore's teeth were half a foot long.

Lapparentosaurus This sauropod was discovered in Madagascar.

Leaellynasaura The only dinosaur ever to be named after a little girl.

Leptoceratops One of the most primitive of all ceratopsians.

Lesothosaurus One of the earliest of all the ornithischian dinosaurs.

Lessemsaurus Named after the popular science writer Don Lessem.

Lexovisaurus One of the oldest European stegosaurs.

Liaoceratops A tiny ceratopsian of early Cretaceous Asia.

Liliensternus One of the largest carnivores of the Triassic period.

Limusaurus Was this toothless theropod a vegetarian?

Linhenykus This tiny dinosaur had single-clawed hands.

Linheraptor This Mongolian raptor was discovered in 2008.

Lophostropheus This theropod lived near the Triassic/Jurassic boundary.

Lourinhanosaurus This hard-to-classify theropod was discovered in Portugal.

Luanchuanraptor A small, poorly understood Asian raptor.

Lufengosaurus A common sight at Chinese natural history museums.

Lurdusaurus This ornithopod resembled a giant sloth.

Lycorhinus This dinosaur was once thought to be a mammal-like reptile.

Magnirostris This ceratopsian had an unusually big beak.

Magnosaurus Once thought to be a species of Megalosaurus.

Magyarosaurus This dwarf titanosaur was probably confined to a small island.

Mahakala This dino-bird was named after a Buddhist deity.

Maiasaura This "good mother lizard" kept close tabs on her young.

Majungatholus Fairly--or unfairly--known as the "cannibal dinosaur."

Malawisaurus The first titanosaur to be found with an intact skull.

Mamenchisaurus The longest-necked dinosaur that ever lived.

Mantellisaurus Named after the famous fossil hunter Gideon Mantell.

Mapusaurus This huge carnivore was closely related to Giganotosaurus.

Marshosaurus Named after the famous paleontologist Othniel C. Marsh.

Masiakasaurus A bizarre, buck-toothed predator of the late Cretaceous.

Massospondylus This small, lithe, bipedal plant-eater roamed the plains of South Africa.

Maxakalisaurus One of the biggest titanosaurs ever found in Brazil.

Medusaceratops This frilled dinosaur was a close relative of Centrosaurus.

Megalosaurus The first dinosaur ever to be discovered and named.

Megapnosaurus Its name is Greek for "big dead lizard."

Megaraptor Despite its name, it wasn't really a raptor.

Mei The current record-holder for "shortest dinosaur name."

Melanorosaurus Probably the largest prosauropod that ever lived.

Metriacanthosaurus Yet another dinosaur that was once mistaken for Megalosaurus.

Microceratops Probably the smallest ceratopsian that ever lived.

Micropachycephalosaurus The current record-holder for longest dinosaur name.

Microraptor This tiny proto-bird had four wings rather than two.

Minmi An early (and very dumb) ankylosaur from Australia.

Minotaurasaurus Named after the half-man, half-bull of Greek myth.

Miragaia This stegosaur had an unusually long neck.

Mirischia Its name means "wonderful pelvis."

Mojoceratops This ceratopsian had a heart-shaped frill.

Monkonosaurus The first dinosaur ever to be discovered in modern-day Tibet.

Monoclonius Might this have been a species of Centrosaurus?

Monolophosaurus This Jurassic predator had a single crest on its skull.

Mononykus This dinosaur may have dug into termite mounds for its lunch.

Mussaurus This "mouse lizard" lived in Triassic South America.

Muttaburrasaurus The most complete dinosaur fossil ever found in Australia.

Mymoorapelta Named after the Mygand-Moore quarry in Colorado.

Nanotyrannus Could this have been a juvenile T. Rex?

Nanshiungosaurus A bizarre therizinosaur from Asia.

Nedcolbertia Named after the famous paleontologist Edwin Colbert.

Neimongosaurus A rare therizinosaur from inner Mongolia.

Nemegtomaia This dinosaur had a bizarrely shaped skull.

Nemegtosaurus This titanosaur has been recreated from a single, incomplete skull.

Neovenator One of the largest carnivorous dinosaurs of western Europe.

Neuquensaurus Was this titanosaur really a species of Saltasaurus?

Nigersaurus This African sauropod had a huge number of teeth.

Noasaurus Were this predator's giant claws on its hands, or on its feet?

Nodocephalosaurus This armored dinosaur has been reconstructed from a single skull.

Nodosaurus One of the first armored dinosaurs ever discovered in North America.

Nomingia This small dinosaur had a peacock-like tail.

Nothronychus The first therizonosaur to be found outside Asia.

Notohypsilophodon A rare South American ornithopod.

Nqwebasaurus One of the few theropods to be discovered in sub-Saharan Africa.

Ojoceratops A very close relative of Triceratops.

Olorotitan One of the most complete dinosaur fossils ever found in Russia.

Omeisaurus One of the most common Chinese sauropods.

Opisthocoelicaudia A clumsily named titanosaur of the late Cretaceous period.

Ornitholestes This "bird robber" probably preyed on small lizards instead.

Ornithomimus This "bird mimic" resembled a modern ostrich.

Orodromeus This tiny herbivore was on Troodon's dinner menu.

Oryctodromeus The only ornithopod known to have lived in burrows.

Othnielia A small, fast herbivore of the late Jurassic.

Ouranosaurus Scientists can't decide if this herbivore had a sail or a hump.

Oviraptor Turns out that this "egg thief" got a bad rap.

Oxalaia This spinosaur was recently discovered in Brazil.

Ozraptor Not much is known about this Australian theropod.

Pachycephalosaurus This plant-eater gave new meaning to the word "blockhead."

Pachyrhinosaurus This "thick-nosed lizard" roamed the North American forests.

Paluxysaurus A contender for the official Texas state dinosaur.

Panoplosaurus A squat, stocky nodosaur of the late Cretaceous.

Panphagia Its name is Greek for "eats everything."

Pantydraco No, this dinosaur didn't wear you-know-what.

Paralititan This huge sauropod was discovered recently in Egypt.

Paranthodon This stegosaur was discovered over 150 years ago.

Parasaurolophus Probably the loudest dinosaur ever to roam the earth.

Patagosaurus This "Patagonian lizard" hailed from South America.

Pawpawsaurus This ancient nodosaur was discovered in Texas.

Pedopenna One of the earliest known dino-birds.

Pelecanimimus This "pelican mimic" sported over 200 teeth.

Pelorosaurus The first sauropod ever to be discovered.

Pentaceratops This "five-horned" herbivore really had only three.

Phuwiangosaurus This titanosaur was discovered in modern-day Thailand.

Piatnitzkysaurus Its teeth were as sharp as its name is funny.

Pinacosaurus Did this ankylosaur roam central Asia in herds?

Pisanosaurus One of the earliest known ornithischian dinosaurs.

Plateosaurus This herd dinosaur blackened the plains of the late Triassic.

Pleurocoelus The official state dinosaur of Texas.

Podokesaurus One of the earliest dinosaurs to live in eastern North America.

Poekilopleuron It may (or may not) have been a species of Megalosaurus.

Polacanthus An extremely spiky ankylosaur of the middle Cretaceous.

Prenocephale This "bonehead" had a round, thick skull.

Prenoceratops A close relative of Leptoceratops.

Probactrosaurus An early stage in hadrosaur evolution.

Proceratosaurus Despite its name, not a close relative of Ceratosaurus.

Procompsognathus Was it an archosaur, or an early dinosaur?

Prosaurolophus The likely ancestor of both Saurolophus and Parasaurolophus.

Protarchaeopteryx "Before Archaeopteryx?" It actually lived millions of years later.

Protoceratops A famous dinosaur with a very funky frill.

Psittacosaurus This dinosaur's noggin wouldn't have looked out of place on a parrot.

Puertasaurus This titanosaur rivaled Argentinosaurus in size.

Pyroraptor This "fire thief" prowled the plains of prehistoric France.

Qantassaurus Named after the national airline of Australia.

Qiaowanlong An Asian relative of Brachiosaurus.

Quaesitosaurus This titanosaur may have had unusually sharp hearing.

Rahonavis Was it a raptor-like bird, or a bird-like raptor?

Rajasaurus This "prince lizard" lived in what is now modern-day India.

Rapetosaurus The only sauropod ever to be discovered on modern-day Madagascar.

Raptorex A pint-sized precursor of T. Rex.

Rebbachisaurus A poorly understood sauropod from northern Africa.

Regnosaurus This stegosaur lived in what is now modern-day England.

Rhabdodon A possible "missing link" between Iguanodon and Hypsilophodon.

Rhoetosaurus A medium-sized sauropod from Down Under.

Richardoestesia Named after the paleontologist Richard Estes.

Rinchenia Named after the famous paleontologist Rinchen Barsbold.

Riojasaurus One of the few prosauropods known to have lived in South America.

Rugops This wrinkly-faced carnivore probably fed on abandoned carcasses.

Saichania This ankylosaur's name is Chinese for "beautiful."

Saltasaurus The first armored sauropod ever to be discovered.

Saltopus Experts aren't sure if this was a dinosaur or an archosaur.

Sanjuansaurus An early theropod from South America.

Santanaraptor Named after Brazil's Santana formation.

Sarahsaurus This prosauropod had unusually strong hands.

Sarcolestes The most likely ancestor of the ankylosaurs.

Sarcosaurus This "flesh lizard" roamed early Jurassic England.

Saturnalia The earliest dinosaur known to have had a herbivorous diet.

Saurolophus One of the few hadrosaurs known to have lived on two continents.

Sauropelta This ankylosaur's armor helped keep raptors at bay.

Saurophaganax The official state dinosaur of Oklahoma.

Sauroposeidon One of the tallest dinosaurs ever to walk the earth.

Saurornithoides A Troodon-like predator from central Asia.

Saurornitholestes A close cousin of Velociraptor.

Scansoriopteryx This early proto-bird probably lived in trees.

Scelidosaurus Among the earliest of all the armored dinosaurs.

Scipionyx One of the most perfectly preserved dinosaur fossils ever found.

Scutellosaurus Probably the smallest of all the armored dinosaurs.

Secernosaurus The first hadrosaur to be discovered in South America.

Seitaad This small dinosaur may have been buried in an avalanche.

Segisaurus An early dinosaur closely related to Coelophysis.

Segnosaurus One of the most unusual (and poorly understood) Cretaceous dinosaurs.

Seismosaurus It was huge, to be sure--but might it have been a species of Diplodocus?

Sellosaurus Another early prosauropod of the Triassic period.

Shantungosaurus The biggest of all the duck-billed dinosaurs.

Shenzhousaurus A small, primitive ornithomimid from China.

Shunosaurus Anatomically speaking, probably the best known of all the sauropods.

Shuvosaurus Was this meat eater an early dinosaur, or a two-legged crocodile?

Shuvuuia Scientists can't decide if it was a dinosaur or a bird.

Siamotyrannus Despite its name, it wasn't a true tyrannosaur.

Silvisaurus This primitive nodosaur was discovered in Kansas.

Similicaudipteryx The juveniles may have been differently feathered than the adults.

Sinocalliopteryx The biggest "dino-bird" yet discovered.

Sinornithoides A small, feathered dinosaur closely related to Troodon.

Sinornithomimus This ornithomimid is known from over a dozen skeletons.

Sinornithosaurus A typical dino-bird of the early Cretaceous.

Sinosauropteryx The first dinosaur proven to have feathers.

Sinovenator This "Chinese hunter" preyed on its fellow dino-birds.

Sinraptor Despite its name, this allosaur wasn't any better or worse than other dinosaurs.

Sinusonasus It sounds like a disease, but it was actually a feathered dinosaur.

Skorpiovenator This "scorpion hunter" really ate meat.

Sonorasaurus The remains of this sauropod were discovered in Arizona.

Sphaerotholus Yet another dome-headed dino from North America.

Spinophorosaurus This early sauropod had a "thagomizer" on its tail.

Spinosaurus This dino was distinguished by the sail-like structure on its back.

Spinostropheus This theropod was once thought to be a species of Elaphrosaurus.

Staurikosaurus Another primitive theropod of the Triassic era.

Stegoceras This small herbivore was built for high-speed head-butting.

Stegosaurus The small-brained, spike-tailed plant eater.

Stenopelix Experts aren't sure how to classify this dinosaur.

Stokesosaurus Some experts think this was the earliest tyrannosaur.

Struthiomimus This "ostrich mimic" roamed the plains of North America.

Struthiosaurus The smallest nodosaur yet discovered.

Stygimoloch Its name means "demon from the river of death." Got your attention yet?

Styracosaurus Winner of the "most elaborate head display" competition.

Suchomimus A fish-eater with a distinctly crocodilian profile.

Supersaurus No, it didn't wear a cape--but this giant dino was still impressive.

Suuwassea Its name is Native American for "ancient thunder."

Suzhousaurus A large, early Cretaceous therizinosaur.

Szechuanosaurus This theropod was a close relative of Sinraptor.

Talarurus This ankylosaur was discovered in the Gobi Desert.

Talenkauen A rare ornithopod from South America.

Tanius Not much is known about this Chinese hadrosaur.

Tanycolagreus This mysterious theropod was once thought to be a species of Coelurus.

Tarascosaurus The only known abelisaur of the northern hemisphere.

Tarbosaurus The second-biggest tyrannosaur after T. Rex.

Tarchia Its name means "brainy," but that may be an exaggeration.

Tastavinsaurus This titanosaur was discovered in Spain.

Tatankacephalus A brand-new ankylosaur from North America.

Tawa This ancient theropod points to a South American origin for dinosaurs.

Technosaurus This early herbivore was named after Texas Tech university.

Telmatosaurus This duck-billed dinosaur was discovered in Transylvania.

Tenontosaurus This long-tailed herbivore was hunted by Deinonychus.

Teratophoneus This "monstrous murderer" wasn't all that big.

Tethyshadros One of the few dinosaurs to be found in modern-day Italy.

Texacephale This Texan pachycephalosaur was named in 2010.

Thecodontosaurus The first prosauropod ever to be discovered.

Theiophytalia Its name means "garden of the gods."

Therizinosaurus What did Little Orphan Annie say to this dinosaur? "Reaping lizards!"

Thescelosaurus Did paleontologists find this dinosaur's mummified heart?

Tianyulong Why did this ornithopod have feathers?

Tianyuraptor A small, long-legged raptor from eastern Asia.

Timimus The only ornithomimid ever discovered in Australia.

Titanoceratops The biggest of all the horned, frilled dinosaurs.

Titanosaurus This sauropod may--or may not--have been a unique member of its genus.

Torosaurus This horned, frilled herbivore was a close cousin of Triceratops.

Torvosaurus One of the largest predators of Jurassic North America.

Triceratops The famous three-horned plant-eater.

Troodon Possibly the smartest dinosaur that ever lived.

Tsaagan One of the earliest raptors yet discovered.

Tsintaosaurus Also known as the "Unicorn Dinosaur."

Tuojiangosaurus One of the most well-known Chinese stegosaurs.

Tylocephale The tallest-domed of all the pachycephalosaurs.

Tyrannosaurus Rex The once--and always--king of the dinosaurs.

Tyrannotitan We know very little about this fearsomely named dinosaur.

Uberabatitan Discovered in the Uberaba region of Brazil.

Udanoceratops The largest ceratopsian to run on two legs.

Unaysaurus One of the oldest prosauropods yet discovered.

Unenlagia This bird-like raptor was native to South America.

Urbacodon This Troodon-like predator was discovered in Uzbekistan.

Utahceratops Guess what state this dinosaur was discovered in?

Utahraptor Probably the biggest raptor that ever lived.

Valdosaurus This ornithopod was discovered on the Isle of Wight.

Variraptor The first raptor ever to be discovered in France.

Velafrons A new addition to the duck-billed dinosaur family.

Velociraptor This dinosaur was vicious--but a lot smaller than you thought.

Vulcanodon An early sauropod of the Jurassic period.

Wannanosaurus Probably the smallest of all the bone-headed dinosaurs.

Wellnhoferia Was it really a species of Archaeopteryx?

Wintonotitan Another new titanosaur from Australia.

Wuerhosaurus Could this have been the last of the stegosaurs?

Xenoposeidon Experts aren't sure how to classify this sauropod.

Xenotarsosaurus A poorly understood abelisaur from South America.

Xiaosaurus A small ornithopod from late Jurassic Asia.

Xiongguanlong A small, primitive tyrannosaur from Asia.

Xixianykus A long-legged dino-bird from eastern Asia.

Xuanhanosaurus You didn't think there'd be so many "X"'s on this list, did you?

Xuanhuaceratops An early ceratopsian of the late Jurassic.

Yamaceratops No, it didn't have a sweet potato for a head.

Yandusaurus A small ornithopod of middle Jurassic China.

Yangchuanosaurus A large theropod of late Jurassic Asia.

Yaverlandia A classic case of mistaken dinosaur identity.

Yimenosaurus One of the better-known Chinese prosauropods.

Yinlong This "hidden dragon" was an early ceratopsian.

Yizhousaurus The earliest intact sauropod yet discovered.

Yunnanosaurus One of the last prosauropods to walk the earth.

Zalmoxes A strange-looking ornithopod from Romania.

Zanabazar Named after a Buddhist spiritual leader.

Zhuchengosaurus This hadrosaur was even bigger than Shantungosaurus.

Zhuchengtyrannus This Asian tyrannosaur was the size of T. Rex.

Zuniceratops This horned dinosaur was discovered by an eight-year-old boy.

Zupaysaurus This "devil lizard" was one of the earliest theropods.

Theories to why dinosaurs disappeared:

Some scientists think dinosaurs died out due to rapid evolution of flowering plants.

It goes like this: Up until the flowering plants came, the dinosaurs ate things like pine needles from evergreen trees. Then flowering plants came, replacing many of the pine trees. Dinosaurs didn't have time to switch their diet to flowers and, as a result, died of starvation.

Another recent and popular theory is: A giant meteorite, 6 miles across, struck the Earth. This collision would have produced an explosive force and damage similar to that of nuclear war. Vast amounts of dust, debris, and ash would have spread quickly around the planet, blocking out the sunlight reaching Earth's surface. Lack of sunlight is believed to have lasted for several months and to have caused temperatures to drop worldwide from 66 degrees Fahrenheit to about 14 degrees. Without sunlight to perform photosynthesis, many plants would have died, causing a domino-like effect on the food chain, including the dinosaurs.

Another theory involves a series of volcanic eruptions in what is now India that formed what we call the Deccan Traps. This massive volcanic episode would likely have had massive climatic changes worldwide. It has even been proposed that the shockwaves from the asteroid impact may have triggered the vulcanism.