Dinosaurs Sitemap - Page 7 2016-09-26

Alphadon - About.com Prehistoric Mammals
Alphadon was an early marsupial of late Cretaceous North America.

Darwinsaurus - About.com Dinosaurs


Eunotosaurus - About.com Prehistoric Reptiles
Did the Permian reptile Eunotosaurus lay at the root of the turtle family tree?

Eusmilus - About.com Prehistoric Mammals
The canines of the prehistoric cat Eusmilus were almost as long as its entire skull.

Bernissartia - About.com Prehistoric Reptiles
Bernissartia was one of the smallest crocodiles of the Cretaceous period.

Ptychodus - About.com Prehistoric Sharks
The giant Cretaceous shark Ptychodus preyed on tiny mollusks.

Dahalokely - About.com Dinosaurs
Dahalokely is a rare theropod dinosaur from the island of Madagascar.

Trilobites, the Dinosaurs of the Arthropod Family
Millions of years before the dinosaurs, trilobites ruled the earth's oceans. Here's a brief description of these unique creatures, and why their fossils are so important to paleontologists.

Gagadon - About.com Prehistoric Mammals
The early Eocene mammal Gagadon was named after pop star Lady Gaga.

Ikrandraco - About.com Pterosaurs
The Asian pterosaur Ikrandraco was named after the flying creatures from

Think You've Found a Dinosaur Egg? Probably Not
Virtually every day, someone in the world discovers what appears to be a clutch of fossilized dinosaur eggs. Unfortunately, the odds that these artifacts were laid by dinosaurs are extremely slim.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

The 10 Reasons Animals Go Extinct
What are the factors that cause plants and animals to go extinct--either hundreds of millions of years ago or in the present day? Here are the 10 most common causes of species extinction.

Prehistoric Life During the Cambrian Period
The Cambrian period is famous for its

Dusicyon (Warrah) - About.com Prehistoric Mammals
The

Steller's Sea Cow - About.com Prehistoric Mammals
Steller's Sea Cow was a Pleistocene ancestor of modern dugongs and manatees.

Prehistoric Life During the Pleistocene Epoch
The most recent geological epoch in earth's history, the Pleistocene witnessed the flourishing - and extinction - of a wide variety of megafauna mammals.

Can We Clone a Woolly Mammoth?
Since Woolly Mammoths are often found preserved in permafrost, they would seem to be ideal candidates for cloning. But how close are we to actually reproducing a living, breathing Mammoth?

Shanweiniao Picture
A picture of the prehistoric bird Shanweiniao. Page 40.

Eoconfuciusornis Picture
A picture of the prehistoric bird Eoconfuciusornis. Page 13.

Dasornis Picture
A picture of the prehistoric bird Dasornis. Page 10.

Eocypselus Picture
A picture of the prehistoric bird Eocypselus. Page 14.

Kairuku Picture
A picture of the prehistoric bird Kairuku. Page 26.

Psilopterus Picture
A picture of the prehistoric bird Psilopterus. Page 37.

Stephens Island Wren Picture
A picture of the Stephens Island Wren. Page 42.

Vegavis Picture
A picture of the prehistoric bird Vegavis.

Gansus Picture
A picture of the prehistoric bird Gansus. Page 19.

Anthropornis Picture
A picture of the prehistoric bird Anthropornis. Page 3.

Waimanu Picture
A picture of the prehistoric bird Waimanu.

Carolina Parakeet Picture
A picture of the Carolina Parakeet. Page 7.

Eskimo Curlew Picture
A picture of the Eskimo Curlew. Dinosaurs. Page 15.

Moa-Nalo Picture
A picture of the Moa-Nalo. Dinosaurs. Page 29.

Mopsitta Picture
A picture of the prehistoric bird Mopsitta. Page 30.

Harpagornis (Giant Eagle) Picture
A picture of Harpagornis, the Giant Eagle. Page 21.

Hesperornis Picture
A picture of the prehistoric bird Hesperornis. Page 22.

Ichthyornis Picture
A picture of the prehistoric bird Ichthyornis. Page 24.

Jeholornis Picture
A picture of the prehistoric bird Jeholornis. Page 25.

Iberomesornis Picture
A picture of the prehistoric bird Iberomesornis. Page 23.

Kelenken Picture
A picture of the prehistoric bird Kelenken. Page 27.

Liaoningornis Picture
A picture of the prehistoric bird Liaoningornis.

Longipteryx Picture
A picture of the prehistoric bird Longipteryx. Page 28.

Osteodontornis Picture
A picture of the prehistoric bird Osteodontornis.

Palaelodus Picture
A picture of the prehistoric bird Palaelodus. Page 31.

Patagopteryx Picture
A picture of the prehistoric bird Patagopteryx. Page 32.

Phorusrhacos (Terror Bird) Picture
A picture of Phorusrhacos, the Terror Bird. Page 34.

Pinguinus (Great Auk) Picture
A picture of Pinguinus, the Great Auk. Page 35.

Presbyornis Picture
A picture of the prehistoric bird Presbyornis. Page 36.

Raphus (Dodo Bird) Picture
A picture of Raphus, the Dodo Bird. Page 38.

Sapeornis Picture
A picture of the prehistoric bird Sapeornis. Page 39.

Shuvuuia Picture
A picture of the prehistoric bird Shuvuuia. Page 41.

Teratornis Picture
A picture of the prehistoric bird Teratornis. Page 43.

Titanis Picture
A picture of the prehistoric bird Titanis. Page 44.

Andalgalornis Picture
A picture of the prehistoric bird Andalgalornis. Page 2.

Pelagornis Picture
A picture of the prehistoric bird Pelagornis. Page 33.

Dromornis (Thunder Bird) Picture
A picture of Dromornis, the Thunder Bird. Page 12.

Aepyornis (Elephant Bird) Picture
A picture of Aepyornis, the Elephant Bird.

Archaeopteryx Picture
A picture of the prehistoric bird Archaeopteryx. Page 4.

Argentavis Picture
A picture of the prehistoric bird Argentavis. Page 5.

Bullockornis Picture
A picture of the prehistoric bird Bullockornis. Page 6.

Confuciusornis Picture
A picture of the prehistoric bird Confuciusornis. Page 8.

Copepteryx Picture
A picture of the prehistoric bird Copepteryx. Page 9.

Dinornis (Giant Moa) Picture
A picture of Dinornis, the Giant Moa. Page 11.

Emeus (Eastern Moa) Picture
A picture of Emeus, the Eastern Moa. Page 17.

Passenger Pigeon Picture
A picture of the Passenger Pigeon. Page 16.

Gastornis (Diatryma) Picture
A picture of the prehistoric bird Gastornis, formerly known as Diatryma. Page 20.

Enantiornis Picture
A picture of the prehistoric bird Enantiornis. Page 18.

Prehistoric Bird Pictures
Pictures, illustrations and photographs of prehistoric and extinct birds, ranging from Archaeopteryx to the Passenger Pigeon.

Genyornis Picture
A picture of the prehistoric bird Genyornis.

Prehistoric Bird Pictures
Pictures, illustrations and photographs of prehistoric and extinct birds, ranging from Archaeopteryx to the Passenger Pigeon.

Prehistoric Bird Pictures
Pictures, illustrations and photographs of prehistoric and extinct birds, ranging from Archaeopteryx to the Passenger Pigeon.

Recently Extinct Reptile #9 - The Giant Monitor Lizard
The Giant Monitor Lizard, a recently extinct reptile.

Recently Extinct Reptile #5 - The Rodrigues Giant Tortoise
The Rodrigues Giant Tortoise, a recently extinct reptile.

Wait, There's More!
Dinosaurs.

Recently Extinct Reptile #6 - The Martinique Giant Ameiva
The Martinique Giant Ameiva, a recently extinct reptile.

10 Recently Extinct Shrews, Bats and Rodents
You might think of them as pests and vermin, but shrews, bats and rodents are every bit as important to our ecosystem as larger mammals. Here's a list of 10 pint-sized mammals that have gone extinct in historical times.

Recently Extinct Rodent #9 - Vespucci's Rodent
Vespucci's Rodent, a recently extinct rodent.

Recently Extinct Rodent #10 - The White-Footed Rabbit-Rat
The White-Footed Rabbit-Rat, a recently extinct rodent.

Wait, There's More!
Dinosaurs.

Recently Extinct Rodent #1 - The Big-Eared Hopping Mouse
The Big-Eared Hopping Mouse, a recently extinct rodent.

Recently Extinct Rodent #2 - The Bulldog Rat
The Bulldog Rat, a recently extinct rodent.

Recently Extinct Rodent #3 - The Dark Flying Fox
The Dark Flying Fox, a recently extinct rodent.

Recently Extinct Rodent #4 - The Giant Vampire Bat
The Giant Vampire Bat, a recently extinct rodent.

Recently Extinct Rodent #5 - The Indefatigable Galapagos Mouse
The Indefatigable Galapagos Mouse, a recently extinct rodent.

Recently Extinct Rodent #6 - The Lesser Stick-Nest Rat
The Lesser Stick-Nest Rat, a recently extinct rodent.

Recently Extinct Rodent #7 - The Puerto Rican Hutia
The Puerto Rican Hutia, a recently extinct rodent.

Recently Extinct Rodent #8 - The Sardinian Pika
The Sardinian Pika, a recently extinct rodent.

10 Recently Extinct Reptiles
Everyone knows about the dinosaurs, but the fact is that some reptiles have gone extinct in historical, rather than deep, time. Here are 10 snakes, turtles and crocodiles that have recently disappeared off the face of the earth.

Recently Extinct Reptile #10 - The Quinkana
The Quinkana, a recently extinct reptile.

Recently Extinct Reptile #4 - The Kawekaweau
The Kawekaweau, a recently extinct reptile.

Recently Extinct Reptile #7 - The Horned Turtle
The Horned Turtle, a recently extinct reptile.

Recently Extinct Reptile #8 - The Wonambi
The Wonambi, a recently extinct reptile.

Recently Extinct Reptile #2 - The Round Island Burrowing Boa
The Round Island Burrowing Boa, a recently extinct reptile.

Recently Extinct Reptile #1 - The Jamaican Giant Galliwasp
The Jamaican Giant Galliwasp, a recently extinct reptile.

Recently Extinct Reptile #3 - The Cape Verde Giant Skink
The Cape Verde Giant Skink, a recently extinct reptile.

Recently Extinct Bird #6 - The Giant Moa
The Giant Moa, a recentlly extinct bird.

Recently Extinct Bird #7 - The Elephant Bird
The Elephant Bird, a recently extinct bird.

10 Recently Extinct Birds
The last 1,000 years have witnessed the extinction of various birds--and some species disappeared off the face of the earth as little as 100 years ago. Here's a list of the 10 most notable birds that have gone extinct in historical times.

Recently Extinct Bird #9 - The Eastern Moa
The Eastern Moa, a recently extinct bird.

Recently Extinct Bird #10 - The Moa-Nalo
The Moa-Nalo, a recently extinct bird.

Recently Extinct Bird #1 - The Eskimo Curlew
The Eskimo Curlew, a recently extinct bird.

Recently Extinct Bird #2 - The Carolina Parakeet
The Carolina Parakeet, a recently extinct bird.

Recently Extinct Bird #3 - The Passenger Pigeon
The Passenger Pigeon, a recently extinct bird.

Recently Extinct Bird #4 - The Stephens Island Wren
The Stephens Island Wren, a recently extinct bird.

Recently Extinct Bird #5 - The Great Auk
The Great Auk, a recently extinct bird.

Recently Extinct Bird #8 - The Dodo Bird
The Dodo Bird, a recently extinct bird.

Wait, There's More!
Dinosaurs.

The Top 10 Candidates for De-Extinction
Ten recently extinct mammals, birds and amphibians that are ripe for de-extinction--and introduction back into the wild.

De-Extinction Candidate #9 - The Gastric-Brooding Frog
The Gastric-Brooding Frog, a popular candidate for de-extinction.

De-Extinction Candidate #10 - The Carolina Parakeet
The Carolina Parakeet, a popular candidate for de-extinction.

De-Extinction Candidate #1 - The Tasmanian Tiger
The Tasmanian Tiger, a popular candidate for de-extinction.

De-Extinction Candidate #2 - The Woolly Mammoth
The Woolly Mammoth, a popular candidate for de-extinction.

De-Extinction Candidate #3 - The Passenger Pigeon
The Passenger Pigeon, a popular candidate for de-extinction.

De-Extinction Candidate #4 - The Quagga
The Quagga, a popular candidate for de-extinction.

De-Extinction Candidate #5 - The Saber-Tooth Tiger
The Saber-Tooth Tiger, a popular candidate for de-extinction.

De-Extinction Candidate #6 - The Dodo Bird
The Dodo Bird, a popular candidate for de-extinction

De-Extinction Candidate #7 - Steller's Sea Cow
Steller's Sea Cow, a popular candidate for de-extinction.

De-Extinction Candidate #8 - The Auroch
The Auroch, a popular candidate for de-extinction.

De-Extinction Step #10 - Cross Your Fingers
Crossing your fingers, the tenth step in a de-extinction program.

De-Extinction Step #8 - Raise the Genetically Engineered Offspring
Raising the genetically engineered offspring, the eighth step in a de-extinction program.

De-Extinction Step #9 - Release the De-Extincted Species into the Wild
Releasing the species into the wild, the ninth step of a de-exinction program.

De-Extinction Step #1`- Obtain Funding
Funding, the first essential step in a de-extinction program.

De-Extinction Step #2 - Identify a Candidate Species
Identifying a candidate species, the second step in a de-extinction program.

De-Extinction Step #6 - Create a Hybrid Genome
Creating a hybrid genome, the sixth step in a de-extinction program.

De-Extinction Step #7 - Engineer and Implant a Living Cell
Engineering and implanting a living cell, the seventh step in a de-extinction program.

De-Extinction Step #5 - Extract Viable Segments of DNA
Extracting segments of DNA, the fifth step in a de-extinction program.

De-Extinction in 10 (Not So Easy) Steps
Do you want to know what, exactly, is involved in de-extincting a long-vanished species? Here's what the process looks like, in 10 easy (or not-so-easy) steps.

De-Extinction Step #4 - Recover Soft Tissues from Preserved Specimens
Recovering soft tissues, the fourth step in a de-extinction program.

De-Extinction Step #3 - Identify a Close Living Relative
Identifying a close living relative, the third step in a de-extinction program.

The Best Advertising Slogans from Dinosaur Movies
A dinosaur movie needs an appropriately monstrous slogan for its poster, TV commercial and DVD box--you'll gain a new appreciation for the art of publicity as you read these prehistoric tag lines.

Did Volcanoes Kill the Dinosaurs?
Most scientists believe that a meteor impact 65 million years ago killed the dinosaurs--but volcanoes may also have been at fault. Did volcanoes, in addition to a meteor impact, cause the K/T Extinction?

How Was Tyrannosaurus Rex Discovered?
How do we know what we know about Tyrannosaurus Rex? Here's a brief fossil history of this famous dinosaur.

Prehistoric Life During the Ordovician Period
Though it's not as well-known as the Cambrian period, the Ordovician period was crucial for the evolution of arthropods and vertebrates. Here's a look at prehistoric life during the Ordovician period.

Prehistoric Life During the Silurian Period
The shortest period of the Paleozic Era, the Silurian marks the time when the first plants and animals colonized dry land. Here's a look at the prehistoric life of the Silurian period.

The Greek Words Used to Name Dinosaurs
When it comes to dinosaur names, it can be hard to distinguish a Micropachycephalosaurus from a Brachytrachelopan. Here's a list of the Greek words used to name dinosaurs, along with their English equivalents.

Megalodon - The Monster Shark Lives! (Not)
What can you say about a TV documentary in which the suspiciously good-looking lead protagonist--

Prehistoric Life During the Paleozoic Era
The Paleozoic Era was when the first complex, multicellular organisms evolved, eventually leading to the archosaurs and therapsids that ushered in the age of dinosaurs. Here's an overview of the prehistoric life that could be found on earth during the Paleozoic Era.

The 10 Worst Dinosaur Names
Not all dinosaurs have lucked out in the name department: some are blessed with cool, sleek, sports-car worthy names, while others are saddled with names that are virtually unpronounceable. Here are the 10 worst dinosaur names, ranging from Becklespinax to Uberabatitan.

Laughable Dinosaur Name #9 - Sinusonasus
Sinusonasus, one of the worst dinosaur names.

Laughable Dinosaur Name #10 - Uberabatitan
Uberabatitan, one of the worst dinosaur names.

Laughable Dinosaur Name #1 - Becklespinax
Becklespinax, one of the worst dinosaur names.

Laughable Dinosaur Name #2 - Dollodon
Dollodon, one of the worst dinosaur names.

Laughable Dinosaur Name #3 - Futalognkosaurus
Futalognkosaurus, one of the worst dinosaur names.

Laughable Dinosaur Name #4 - Ignavusaurus
Ignavusaurus, one of the worst dinosaur names.

Laughable Dinosaur Name #5 - Monoclonius
Monoclonius, one of the worst dinosaur names.

Laughable Dinosaur Name #6 - Opisthocoelicaudia
Opisthocoelicaudia, one of the worst dinosaur names.

Laughable Dinosaur Name #7 - Piatnitzkysaurus
Piatnitzkysaurus, one of the worst dinosaur names.

Laughable Dinosaur Name #6 - Pantydraco
Pantydraco, one of the worst dinosaur names.

Wait, There's More!
Dinosaurs.

Deinosuchus - About.com Prehistoric Crocodiles
Deinosuchus was one of the most fearsome crocodiles of late Cretaceous North America.

Kaprosuchus (BoarCroc) - About.com Prehistoric Reptiles
The middle Cretaceous Kaprosuchus, also known as the BoarCroc, had some very big teeth.

Beelzebufo (Devil Frog) - About.com Prehistoric Amphibians
Beelzebufo, also known as the Devil Frog, was a giant frog of late Cretaceous Madagascar.

Pterodactylus - About.com Pterosaurs
Pterodactylus was the first pterosaur ever to be discovered, and is still the most famous.

Rodhocetus - About.com Prehistoric Mammals
The Eocene mammal Rodhocetus was an early step in the evolution of whales.

Helicoprion - About.com Prehistoric Sharks
The early Permian shark Helicoprion had teeth like a fruit roll-up.

Pliosaurus - About.com Marine Reptiles
A complete skeleton of Pliosaurus was recently discovered in Norway.

Plateosaurus - About.com Dinosaurs
The herd dinosaur Plateosaurus blackened the plains of late Triassic Europe.

Indohyus - About.com Prehistoric Mammals
The ancient hoofed mammal Indohyus may (or may not) have been ancestral to whales.

Gastornis (Diatryma) - About.com Prehistoric Birds
The giant Eocene bird Gastornis was previously known as Diatryma.

Lystrosaurus - About.com Prehistoric Reptiles
The unusually widespread therapsid reptile Lystrosaurus preceded the dinosaurs.

Pachycephalosaurus - About.com Dinosaurs
The thick-skulled dinosaur Pachycephalosaurus gave new meaning to the word

Pikaia - About.com Prehistoric Fish
The early Cambrian Pikaia may have been the ancestor of all living vertebrates.

Edaphosaurus - About.com Prehistoric Reptiles
The early pelycosaur reptile Edaphosaurus was a close cousin of Dimetrodon.

Archelon - About.com Marine Reptiles
The dinosaur-sized prehistoric turtle Archelon lived during the late Cretaceous period.

Ambulocetus - About.com Prehistoric Mammals
The

Amphicyon - About.com Prehistoric Mammals
The remote canine ancestor Amphicyon is also known as the

Plesiosaurus - About.com Marine Reptiles
The long-necked Plesiosaurus set the prehistoric standard for marine reptiles.

Knightia - About.com Prehistoric Fish
The Eocene fish Knightia has left literally thousands of fossils.

The Dinosaurs of Flaming Cliffs
The Cretaceous fossil bed Flaming Cliffs is every bit as hot as its name implies.

The Dinosaurs of Cedar Mountain
The Cedar Mountain Formation is a particularly fertile stretch of the Morrison Formation.

The Dinosaurs of Dinosaur Provincial Park
More complete dinosaur skeletons have been found in Dinosaur Provincial Park than anywhere else in the world.

The Dinosaurs of Dinosaur National Monument
Dinosaur National Monument is a treasure trove of dinosaur fossils from the late Jurassic.

The Dinosaurs of the Dashanpu Formation
The Chinese quarry known as the Dashanpu Formation is unusually rich in sauropod fossils.

The Dinosaurs of the Solnhofen Formation
The Solnhofen Formation in Germany has yielded numerous specimens of Archaeopteryx.

The Dinosaurs of the Karoo Basin
This fossil-rich formation known as the Karoo Basin covers two-thirds of South Africa.

Dinosaur Fossil at Hell Creek
A huge variety of dinosaurs lived--and died--in the early Cretaceous forest of Hell Creek.

Dinosaur Fossil at Ghost Ranch
Thousands of Coelophysis skeletons have been discovered in the Ghost Ranch quarry.

Xiphactinus - About.com Prehistoric Fish
The 20-foot-long Xiphactinus is one of the largest bony fish in the fossil record.

Stethacanthus - About.com Prehistoric Sharks
The males of the Devonian shark Stethacanthus had

Squalicorax - About.com Prehistoric Sharks
Squalicorax is the only prehistoric shark known to have preyed on dinosaurs.

Seymouria - About.com Prehistoric Amphibians
The Permian amphibian Seymouria was once mistaken for a true reptile.

Panderichthys - About.com Prehistoric Fish
The Devonian fish Panderichthys had some primitive tetrapod characteristics.

Otodus - About.com Prehistoric Sharks
All that remains of the Eocene shark Otodus are its huge, sharp teeth.

Myllokunmingia - About.com Prehistoric Fish
Myllokunmingia was a tiny proto-fish of the early Cambrian period.

Metoposaurus - About.com Prehistoric Amphibians
The late Triassic amphibian Metoposaurus had an amazingly flat head.

Megapiranha - About.com Prehistoric Fish
The piranha ancestor Megapiranha had a dangerously powerful bite.

Leedsichthys - About.com Prehistoric Fish
The Jurassic Leedsichthys was one of the largest prehistoric fish that ever lived.

Ichthyostega - About.com Tetrapods
The late Devonian Ichthyostega was one of the first identified tetrapods.

Hybodus - About.com Prehistoric Sharks
The medium-sized shark Hybodus prowled the earth's seas for over 100 million years.

Haikouichthys - About.com Prehistoric Fish
The early Cambrian Haikouichthys may (or may not) have been ancestral to all fish.

Greererpeton - About.com Tetrapods
The Carboniferous tetrapod Greererpeton looked a lot like an eel.

Edestus - About.com Prehistoric Sharks
The Carboniferous shark Edestus could have used a visit to the orthodontist.

Dipterus - About.com Prehistoric Fish
Dipterus was a prehistoric lungfish of the Devonian period.

Cyclotosaurus - About.com Prehistoric Amphibians
The massive amphibian Cyclotosaurus had a worldwide distribution during the Triassic period.

Cladoselache - About.com Prehistoric Sharks
Cladoselache was a strange, scaleless prehistoric shark of the late Devonian period.

Cretoxyrhina - About.com Prehistoric Sharks
The Cretaceous predator Cretoxyrhina is better known as the

Amphibamus - About.com Prehistoric Amphibians
The late Carboniferous Amphibamus is one of the earliest identified prehistoric amphibians.

Acanthostega - About.com Tetrapods
Acanthostega is one of the most well-known tetrapods of the Devonian period.

Joan Wiffen – Profile of the Famous Paleontologist
The self-taught fossil hunter Joan Wiffen made important discoveries in New Zealand.

Patricia Vickers-Rich - Profile of the Famous Paleontologist
The Australian paleontologist Patricia Vickers-Rich likes to name dinosaurs after her kids.

Ernst Stromer – Profile of the Famous Paleontologist
All of the fossils discovered by Ernst Stromer were destroyed in World War II.

Paul Sereno - Profile of the Famous Paleontologist
Paul Sereno is one of the most popular paleontologists of the TV generation.

Harry Seeley - Profile of the Famous Paleontologist
Harry Seeley was the scientist who divided dinosaurs into ornithischians and saurischians.

Richard Owen - Profile of the Famous Paleontologist
The English naturalist Richard Owen was the man who invented the word

Henry Fairfield Osborn - Profile of the Famous Paleontologist
Henry Fairfield Osborn was the man who named both Velociraptor and Tyrannosaurus Rex.

John H. Ostrom - Profile of the Famous Paleontologist
John H. Ostrom was the first modern scientist to propose that birds evolved from dinosaurs.

Othniel C. Marsh - Profile of the Famous Paleontologist
The American paleontologist Othniel C. Marsh was one of the antagonists in the

Gideon Mantell - Profile of the Famous Paleontologist
The English naturalist Gideon Mantell deserves the credit for discovering Iguanodon.

Joseph Leidy - Profile of the Famous Paleontologist
Joseph Leidy is famous for naming the official state dinosaur of New Jersey.

Lawrence M. Lambe - Profile of the Famous Paleontologist
Lawrence M. Lambe was one of the first, and most famous, fossil hunters of Canada.

Jack Horner - Profile of the Famous Paleontologist
Paleontologist Jack Horner was the inspiration for Sam Neill's character in Jurassic Park.

Sue Hendrickson - Profile of the Famous Fossil Hunter
Sue Hendrickson is famous for discovering the largest-ever specimen of Tyrannosaurus Rex.

Dong Zhiming - Profile of the Famous Paleontologist
The Chinese paleontologist Dong Zhiming has discovered a huge number of dinosaurs.

Charles Darwin - Profile of the Famous Naturalist
Charles Darwin is the man who introduced the world to the theory of evolution.

Georges Cuvier - Profile of the Famous Naturalist
Georges Cuvier was one of the first scientists to propose that species can go extinct.

Edward Drinker Cope - Profile of the Famous Paleontologist
The American paleontologist Edward Drinker Cope was one of the antagonists of the

Edwin H. Colbert - Profile of the Famous Paleontologist
The paleontologist Edwin H. Colbert helped prove the theory of continental drift.

William Buckland - Profile of the Famous Naturalist
The English naturalist William Buckland was the first person ever to name a dinosaur.

Barnum Brown - Profile of the Famous Paleontologist
The famous fossil hunter Barnum Brown was named after impresario P.T. Barnum.

Jose F. Bonaparte - Profile of the Famous Paleontologist
Jose F. Bonaparte is South America's most prolific paleontologist.

Rinchen Barsbold - Profile of the Famous Paleontologist
Rinchen Barsbold is the most famous paleontologist of Mongolia.

Robert Bakker - Profile of the Famous Paleontologist
The American paleontologist Robert Bakker is a forceful advocate of warm-blooded dinosaurs.

Mary Anning - Profile of the Famous Paleontologist
The English fossil hunter Mary Anning was the inspiration for

Roy Chapman Andrews - Profile of the Famous Paleontologist
The American fossil hunter Roy Chapman Andrews may have been the inspiration for Indiana Jones.

Luis Alvarez - Profile of the Famous Scientist
Luis Alvarez, along with his son Walter, discovered the reason dinosaurs went extinct.

Tetrapodophis - About.com Prehistoric Snakes
Was Tetrapodophis really a snake, and did it really have four legs?

Thrinaxodon - About.com Prehistoric Reptiles
The therapsid reptile Thrinaxodon had a lot in common with modern cats.

Stomatosuchus - About.com Prehistoric Reptiles
The giant Cretaceous crocodile Stomatosuchus fed on tiny plankton.

Protoavis - About.com Prehistoric Reptiles
Despite its name, the Triassic reptile Protoavis wasn't really the

Postosuchus - About.com Prehistoric Reptiles
The Triassic archosaur Postosuchus looked a lot like a true dinosaur.

Odontochelys - About.com Prehistoric Reptiles
Could the late Triassic Odontochelys have been the first true turtle?

Najash - About.com Prehistoric Reptiles
The two-legged snake Najash was named after the serpent in the book of Genesis.

Moschops - About.com Prehistoric Reptiles
Moschops was one of the largest therapsid reptiles before the rise of the dinosaurs.

Marasuchus - About.com Prehistoric Reptiles
Was the South American Marasuchus an advanced archosaur, or an early dinosaur?

Madtsoia - About.com Prehistoric Reptiles
The prehistoric snake Madtsoia persisted from the Cretaceous to the Pleistocene.

Longisquama - About.com Prehistoric Reptiles
The middle Triassic reptile Longisquama sported strange, featherlike plumes.

Lagosuchus - About.com Archosaurs
Could the tiny reptile Lagosuchus have been the ancestor of all the dinosaurs?

Hylonomus - About.com Prehistoric Reptiles
Might the late Carboniferous Hylonomus have been the first true reptile?

Haasiophis - About.com Prehistoric Reptiles
Haasiophis was a two-legged snake of the late Cretaceous period.

Gigantophis - About.com Prehistoric Reptiles
The late Eocene Gigantophis was once thought to be world's biggest prehistoric snake.

Euparkeria - About.com Prehistoric Reptiles
The African Euparkeria was a tiny, quick, and voracious predecessor of the first dinosaurs.

Desmatosuchus - About.com Prehistoric Reptiles
The crocodile-like archosaur Desmatosuchus possessed a fish-like head.

Coelurosauravus - About.com Prehistoric Reptiles
The tiny Permian reptile Coelurosauravus glided from tree to tree.

Chimaerasuchus - About.com Prehistoric Reptiles
The middle Cretaceous Chimaerasuchus was the first identified vegetarian crocodile.

Carbonemys - About.com Prehistoric Reptiles
The one-ton turtle Carbonemys shared its habitat with the giant snake Titanoboa.

Asilisaurus - About.com Prehistoric Reptiles
The middle Triassic Asilisaurus is an important link in the evolution of dinosaurs.

Allaeochelys - About.com Prehistoric Reptiles
The Eocene turtle Allaeochelys was fossilized in the act of mating.

Aegisuchus - About.com Prehistoric Reptiles
The Cretaceous crocodile Aegisuchus is better known as the

Titanis - About.com Prehistoric Birds
The Pleistocene bird Titanis is the star of the horror novel

Thunder Bird (Dromornis) - About.com Prehistoric Birds
Dromornis, the Thunder Bird, was a Miocene contender for

Terror Bird (Phorusrhacos) - About.com Prehistoric Birds
Phorusrhacos, also known as the Terror Bird, was as scary as its name is hard to pronounce.

Pelagornis - About.com Prehistoric Birds
The late Miocene Pelagornis was one of the biggest flying birds that ever lived.

Mopsitta - About.com Prehistoric Birds
Did the Scandinavian parrot Mopsitta really

Suchomimus - About.com Dinosaurs
The fish-eating dinosaur Suchomimus cut a distinctly crocodile-like profile.

Inkayacu - About.com Prehistoric Birds
The Eocene penguin Inkayacu was covered with red and gray feathers.

Pentaceratops - About.com Dinosaurs
The

Ichthyornis - About.com Prehistoric Birds
The late Cretaceous

Haast's Eagle (Harpagornis) - About.com Prehistoric Birds
The Pleistocene bird Harpagornis, also known as Haast's Eagle, was the biggest eagle that ever lived.

Icadyptes - About.com Prehistoric Birds
Icadyptes, also known as the Giant Penguin, made its home in Eocene Peru.

Genyornis - About.com Prehistoric Birds
The ostrich-like bird Genyornis was hunted to death in Australia 50,000 years ago.

Confuciusornis - About.com Prehistoric Birds
The prehistoric bird Confuciusornis was named after the famous Chinese philosopher.

Aurornis - About.com Prehistoric Birds
The

Argentavis - About.com Prehistoric Birds
The South American Argentavis was one of the biggest flying birds that ever lived.

Zygorhiza – About.com Prehistoric Mammals
The Eocene whale Zygorhiza may have crawled onto dry land to give birth.

Woolly Rhino (Coelodonta) - About.com Prehistoric Mammals
Coelodonta, the Woolly Rhino, was a shaggy rhinoceros of Pleistocene Eurasia.

Uintatherium - About.com Prehistoric Mammals
The rhinoceros-like prehistoric mammal Uintatherium sported three pairs of horns.

Tomarctus - About.com Prehistoric Mammals
Tomarctus was a bone-crushing dog of Miocene North America.

Thylacosmilus - About.com Prehistoric Mammals
The South American Thylacosmilus was a marsupial variant of the saber-toothed tiger.

Straight-Tusked Elephant - About.com Prehistoric Mammals
The Straight-Tusked Elephant of western Europe went extinct 50,000 years ago.

Steropodon - About.com Prehistoric Mammals
Steropodon was an early Cretaceous ancestor of the modern platypus.

Stegomastodon - About.com Prehistoric Mammals
Stegomastodon wasn't quite a cross between a Stegosaurus and a Mastodon.

Squalodon - About.com Prehistoric Whales
The

Sivatherium - About.com Prehistoric Mammals
The prehistoric giraffe Sivatherium looked more like a moose.

Sivapithecus (Ramapithecus) - About.com Prehistoric Mammals
Sivapithecus, also known as Ramapithecus, may have been ancestral to modern orangutans.

Repenomamus - About.com Prehistoric Mammals
The Cretaceous mammal Repenomamus was found with the remains of a dinosaur in its stomach.

Purgatorius - About.com Prehistoric Mammals
Was the Cretaceous mammal Purgatorius the distant ancestor of modern humans?

Ptilodus - About.com Prehistoric Mammals
The squirrel-like prehistoric mammal Ptilodus had a prehensile tail.

Pseudaelurus - About.com Prehistoric Mammals
Pseudaelurus was a direct, but ancient, ancestor of modern felines.

Propliopithecus (Aegyptopithecus) - About.com Prehistoric Mammals
The Oligocene ape Propliopithecus resembled a small gibbon.

Proconsul - About.com Prehistoric Mammals
Was the Miocene primate Proconsul the first true ape?

Pliohippus - About.com Prehistoric Mammals
The ancestral horse Pliohippus was built for speed.

Pliopithecus - About.com Prehistoric Mammals
Pliopithecus was one of the first prehistoric primates ever to be identified.

Plesiadapis - About.com Prehistoric Mammals
The Paleocene mammal Plesiadapis is one of the earliest known primates.

Pakicetus - About.com Prehistoric Mammals
The dog-like mammal Pakicetus was ancestral to modern whales.

Oreopithecus - About.com Prehistoric Mammals
Paleontologists sometimes call the Miocene primate Oreopithecus the

Obdurodon - About.com Prehistoric Mammals
The prehistoric platypus Obdurodon was equipped with a big, toothy bill.

Nuralagus - About.com Prehistoric Mammals
The Pliocene Nuralagus was the largest rabbit that ever lived.

Myotragus (Cave Goat) - About.com Prehistoric Mammals
Did the prehistoric cave goat Myotragus have a cold-blooded metabolism?

Moeritherium - About.com Prehistoric Mammals
The prehistoric elephant Moeritherium was only about the size of a pig.

Mesohippus - About.com Prehistoric Mammals
The

Merychippus - About.com Prehistoric Mammals
The late Miocene Merychippus was an important intermediate genus in horse evolution.

Leptocyon - About.com Prehistoric Mammals
Leptocyon was a tiny, foxlike ancestor of the modern dog.

Megazostrodon - About.com Prehistoric Mammals
Megazostrodon was a transitional form between therapsid reptiles and true mammals.

Megatherium (Giant Sloth) - About.com Prehistoric Mammals
The prehistoric sloth Megatherium was bigger than an elephant.

Megantereon - About.com Prehistoric Mammals
Megantereon was one of the most successful saber-toothed cats of the Cenozoic Era.

Macrauchenia - About.com Prehistoric Mammals
Macrauchenia looked like a horse crossed with a camel crossed with an elephant.

Leptictidium - About.com Prehistoric Mammals
Leptictidium was a tiny, leaping prehistoric mammal of the Eocene epoch.

Kutchicetus - About.com Prehistoric Mammals
The prehistoric whale Kutchicetus was a long-tailed relative of Ambulocetus.

Juramaia - About.com Prehistoric Mammals
The

Homotherium - About.com Prehistoric Mammals
The

Icaronycteris - About.com Prehistoric Mammals
Icaronycteris is one of the earliest bats yet identified in the fossil record.

Eohippus - About.com Prehistoric Mammals
The famous Eocene horse Eohippus is sometimes referred to as Hyracotherium.

Hyaenodon - About.com Prehistoric Mammals
This fearsome meat-eater Hyaenodon was the Eocene equivalent of a wolf.

Hesperocyon - About.com Prehistoric Mammals
Hesperocyon was a distant Eocene ancestor of the modern dog.

Glyptodon - About.com Prehistoric Mammals
The prehistoric armadillo Glyptodon was the size of a Volkswagen Beetle.

Gigantopithecus - About.com Prehistoric Mammals
The Pleistocene primate Gigantopithecus was twice the size of modern gorillas.

Giant Short-Faced Bear - About.com Prehistoric Mammals
The Giant Short-Faced Bear was one of the largest ursines ever to walk the earth.

Giant Hyena (Pachycrocuta) - About.com Prehistoric Mammals
The Giant Hyena, also known as Pachycrocuta, was three times the size of a modern hyena.

Giant Beaver (Castoroides) - About.com Prehistoric Mammals
The Giant Beaver, also known as Castoroides, weighed upwards of 200 pounds.

Epicyon - About.com Prehistoric Mammals
The prehistoric dog Epicyon was built more like a big cat.

Eozostrodon - About.com Prehistoric Mammals
The late Triassic Eozostrodon may (or may not) have been the first true mammal.

Eosimias - About.com Prehistoric Mammals
The

Entelodon (Killer Pig) - About.com Prehistoric Mammals
Entelodon, aka the

Dwarf Elephant - About.com Prehistoric Mammals
The pint-sized Dwarf Elephant went extinct shortly after the last Ice Age.

Dryopithecus - About.com Prehistoric Mammals
Guess where the

Dorudon - About.com Prehistoric Mammals
The prehistoric whale Dorudon was once mistaken for a baby Basilosaurus.

Dinohippus - About.com Prehistoric Mammals
The prehistoric horse Dinohippus wasn't quite as fearsome as its name implies.

Desmostylus - About.com Prehistoric Mammals
Desmostylus was a strange, hippopotamus-like mammal of the Miocene epoch.

Deinotherium - About.com Prehistoric Mammals
Deinotherium was one of the largest prehistoric elephants ever to walk the earth.

Darwinius - About.com Prehistoric Mammals
Did the Eocene primate Darwinius lie at the root of the human evolutionary tree?

Daeodon (Dinohyus) - About.com Prehistoric Mammals
The prehistoric pig Daeodon, also known as Dinohyus, was the size of a rhinoceros.

Cynodictis - About.com Prehistoric Mammals
The late Eocene Cynodictis was once thought to be the first true dog.

Crusafontia - About.com Prehistoric Mammals
The prehistoric mammal Crusafontia had some decidedly squirrel-like characteristics.

Cimexomys - About.com Prehistoric Mammals
Did the tiny Cretaceous mammal Cimexomys feast on Troodon eggs?

Chalicotherium - About.com Prehistoric Mammals
The prehistoric mammal Chalicotherium looked like a cross between a horse and a gorilla.

Cave Hyena - About.com Prehistoric Mammals
The Pleistocene Cave Hyena competed with early humans for living space.

Caribbean Monk Seal - About.com Prehistoric Mammals
Christopher Columbus referred to the Caribbean Monk Seal as the

Dunkleosteus - About.com Prehistoric Fish
Dunkleosteus was a huge, armored

Borophagus - About.com Prehistoric Mammals
Borophagus was one of the biggest of the bone-crushing canids.

Baiji - About.com Prehistoric Mammals
This dolphin known as the Baiji once lived in China's Yangtze River.

Australopithecus - About.com Prehistoric Mammals
The Pleistocene hominid Australopithecus was the immediate predecessor of genus Homo.

Archicebus - About.com Prehistoric Mammals
Was the tiny, mouse-like mammal Archicebus the first true primate?

Afropithecus - About.com Prehistoric Mammals
The African primate Afropithecus was discovered by Richard and Mary Leakey.

Tupuxuara - About.com Pterosaurs
Tupuxuara was a colorful South American pterosaur closely (and confusingly) related to Tapejara.

Tropeognathus - About.com Pterosaurs
The

Tapejara - About.com Pterosaurs
The colorful pterosaur Tapejara flew the skies of Cretaceous South America.

Rhamphorhynchus - About.com Pterosaurs
The fossils of the pterosaur Rhamphorhynchus are unusually well preserved.

Pterodaustro - About.com Pterosaurs
The early Cretaceous Pterodaustro was a weirdly beaked cousin of Pterodactylus.

Pteranodon - About.com Pterosaurs
Pteranodon is the pterosaur most people refer to when they say

Ornithocheirus - About.com Pterosaurs
Ornithocheirus was one of the largest pterosaurs of the middle Cretaceous period.

Nyctosaurus - About.com Pterosaurs
The Cretaceous pterosaur Nyctosaurus came equipped with its own mast and sail.

Jeholopterus - About.com Pterosaurs
The Asian pterosaur Jeholopterus was once thought to resemble a vampire bat.

Hatzegopteryx - About.com Pterosaurs
Was the giant pterosaur Hatzegopteryx even bigger than Quetzalcoatlus?

Dimorphodon - About.com Pterosaurs
The big-headed pterosaur Dimorphodon had two distinct types of teeth.

Coloborhynchus - About.com Pterosaurs
Coloborhynchus is the largest toothed pterosaur yet identified.

Aetodactylus - About.com Pterosaurs
The Cretaceous pterosaur Aetodactylus had an unusually narrow beak.

Utatsusaurus - About.com Marine Reptiles
The Japanese Utatsusaurus is one of the earliest ichthyosaurs yet identified.

Tylosaurus - About.com Marine Reptiles
Tylosaurus was a slim, sleek marine reptile of the late Cretaceous period.

Temnodontosaurus - About.com Marine Reptiles
The dolphin-shaped marine reptile Temnodontosaurus gave birth to live young.

Tanystropheus - About.com Prehistoric Reptiles
The elongated neck of the archosaur Tanystropheus looked like a rubber pencil.

Styxosaurus - About.com Marine Reptiles
The long-necked marine reptile Styxosaurus was a relative of Elasmosaurus.

Shonisaurus - About.com Marine Reptiles
Shonisaurus was one of the largest marine reptiles of the Mesozoic Era.

Shastasaurus - About.com Marine Reptiles
The giant Triassic marine reptile Shastasaurus fed on soft-bodied cephalopods.

Platypterygius - About.com Marine Reptiles
Platypterygius was one of the rare ichthyosaurs to survive into the Cretaceous period.

Placodus - About.com Marine Reptiles
The blunt-headed marine reptile Placodus sucked shellfish off the ocean floor.

Pachyrhachis - About.com Marine Reptiles
Pachyrhachis was an early Cretaceous ancestor of modern snakes.

Ophthalmosaurus - About.com Marine Reptiles
The late Jurassic marine reptile Ophthalmosaurus was distinguished by its enormous eyes.

Mauisaurus - About.com Marine Reptiles
Mauisaurus is one of the few marine reptiles ever to be discovered in New Zealand.

Malawania - About.com Marine Reptiles
Malawania was a dolphin-like marine reptile of the early Cretaceous period.

Ichthyosaurus - About.com Marine Reptiles
Ichthyosaurus was a remarkably fish-like marine reptile of the early Jurassic period.

Nothosaurus - About.com Marine Reptiles
The

Mosasaurus - About.com Marine Reptiles
Mosasaurus was the first prehistoric marine reptile ever to receive a name.

Mesosaurus - About.com Marine Reptiles
The marine reptile Mesosaurus helped confirm the theory of continental drift.

Megalneusaurus - About.com Marine Reptiles
The Jurassic marine reptile Megalneusaurus rivaled Liopleurodon in size.

Macroplata - About.com Marine Reptiles
The marine reptile Macroplata looked like a cross between a plesiosaur and a pliosaur.

Hydrotherosaurus - About.com Marine Reptiles
The

Hainosaurus - About.com Marine Reptiles
At 50 feet long, Hainosaurus was one of the biggest mosasaurs that ever lived.

Dallasaurus - About.com Marine Reptiles
Guess which city the marine reptile Dallasaurus was named after?

Dakosaurus - About.com Marine Reptiles
The fierce marine crocodile Dakosaurus possessed a dinosaur-like head.

Cymbospondylus - About.com Marine Reptiles
Cymbospondylus was a very large ichthyosaur of the middle Triassic period.

Cryptoclidus - About.com Marine Reptiles
Cryptoclidus was a classic, sleek, long-necked plesiosaur of the late Jurassic period.

Attenborosaurus - About.com Marine Reptiles
The marine reptile Attenborosaurus was named after the filmmaker David Attenborough.

Acamptonectes - About.com Marine Reptiles
The

Zhuchengtyrannus - About.com Dinosaurs
The Asian tyrannosaur Zhuchengtyrannus was the size of T. Rex.

Zuniceratops - About.com Dinosaurs
The horned dinosaur Zuniceratops was discovered by an eight-year-old boy.

Zanabazar - About.com Dinosaurs
The central Asian dinosaur Zanabazar was named after a Tibetan spiritual leader.

Zalmoxes - About.com Dinosaurs
Zalmoxes was a strange-looking ornithopod dinosaur from Romania.

Yi Qi - About.com Dinosaurs
The strange Jurassic dinosaur Yi Qi possessed bat-like wings.

Yutyrannus - About.com Dinosaurs
Yutyrannus is one of the largest feathered tyrannosaur dinosaurs yet identified.

Yaverlandia - About.com Dinosaurs
Yaverlandia is a classic case study of mistaken dinosaur identity.

Xuanhanosaurus - About.com Dinosaurs
The small, big-headed dinosaur Xuanhanosaurus prowled late Jurassic Asia.

Xinjiangtitan - About.com Dinosaurs
The huge sauropod dinosaur Xinjiangtitan was a close relative of Mamenchisaurus.

Venenosaurus - About.com Dinosaurs
The

Xenoceratops - About.com Dinosaurs
The

Vulcanodon - About.com Dinosaurs
The

Utahceratops - About.com Dinosaurs
Guess which state the horned, frilled dinosaur Utahceratops was discovered in?

Unenlagia - About.com Dinosaurs
The bird-like dinosaur Unenlagia was native to South America.

Tyrannotitan - About.com Dinosaurs
We know very little about the fearsomely named dinosaur Tyrannotitan.

Tuojiangosaurus - About.com Dinosaurs
Tuojiangosaurus is one of the best known stegosaur dinosaurs of Asia.

Tsintaosaurus - About.com Dinosaurs
The Asian duckbill Tsintaosaurus is also known as the

Torvosaurus - About.com Dinosaurs
Torvosaurus was one of the largest meat-eating dinosaurs of Jurassic North America.

Torosaurus - About.com Dinosaurs
Was the dinosaur Torosaurus really a superannuated specimen of Triceratops?

Tornieria - About.com Dinosaurs
The sauropod dinosaur Tornieria has a complicated taxonomic history.

Titanosaurus - About.com Dinosaurs
The giant dinosaur Titanosaurus may, or may not, be a valid genus of titanosaur.

Titanoceratops - About.com Dinosaurs
Titanoceratops was the biggest of all the horned, frilled dinosaurs.

Tianchisaurus - About.com Dinosaurs
The dinosaur Tianchisaurus was named after the cast of

Thescelosaurus - About.com Dinosaurs
Did paleontologists really find the mummified heart of Thescelosaurus?

Tenontosaurus - About.com Dinosaurs
The duck-billed dinosaur Tenontosaurus was on Deinonychus' lunch menu.

Telmatosaurus - About.com Dinosaurs
The duck-billed dinosaur Telmatosaurus was discovered in Transylvania.

Tawa - About.com Dinosaurs
The tiny Tawa points to a South American origin for dinosaurs.

Tarchia - About.com Dinosaurs
Tarchia is Chinese for

Tarbosaurus - About.com Dinosaurs
The meat-eating dinosaur Tarbosaurus was almost as big as T. Rex.

Stygimoloch - About.com Dinosaurs
The name Stygimoloch means

Struthiomimus - About.com Dinosaurs
The

Staurikosaurus - About.com Dinosaurs
Staurikosaurus was one of the first true dinosaurs of Triassic South America.

Sinoceratops - About.com Dinosaurs
Sinoceratops is a rare horned, frilled dinosaur of late Cretaceous China.

Sinraptor - About.com Dinosaurs
Despite its name, Sinraptor wasn't any better or worse than other dinosaurs.

Sinosaurus - About.com Dinosaurs
The dinosaur Sinosaurus was once classified as an Asian species of Dilophosaurus.

Sinosauropteryx - About.com Dinosaurs
The Asian Sinosauropteryx was the first identified feathered dinosaur.

Sinornithosaurus - About.com Dinosaurs
Did the feathered dinosaur Sinornithosaurus really have poisonous fangs?

Siats - About.com Dinosaurs
Siats was one of the largest theropod dinosaurs of North America.

Shunosaurus - About.com Dinosaurs
Anatomically speaking, the Asian Shunosaurus is the best known sauropod dinosaur.

Shantungosaurus - About.com Dinosaurs
Shantungosaurus was one of the largest duck-billed dinosaurs of the Mesozoic Era.

Seismosaurus - About.com Dinosaurs
It was huge, but might Seismosaurus have been a species of Diplodocus?

Segnosaurus - About.com Dinosaurs
Segnosaurus is one of the most unusual, and poorly understood, therizinosaur dinosaurs.

Segisaurus - About.com Dinosaurs
The early dinosaur Segisaurus was closely related to Coelophysis.

Scutellosaurus - About.com Dinosaurs
The North American Scutellosaurus was one of the smallest armored dinosaurs.

Sciurumimus - About.com Dinosaurs
The

Scipionyx - About.com Dinosaurs
Scipionyx is one of the most perfectly preserved dinosaur fossils ever discovered.

Scelidosaurus - About.com Dinosaurs
Scelidosarus was one of the earliest armored dinosaurs.

Scansoriopteryx - About.com Dinosaurs
The early feathered dinosaur Scansoriopteryx probably lived in trees.

Saurornitholestes - About.com Dinosaurs
The feathered dinosaur Saurornitholestes was a close cousin of Velociraptor.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

10 Recently Extinct Lions, Tigers and Big Cats
The last 10,000 years have witnessed the extinction of a large number of lions, tigers and cheetahs, with many species surviving well into the 19th or early 20th centuries. Here are the 10 most notable big cats that have gone extinct in historical times.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Dinosaurs
Dinosaurs.

Why Did T. Rex Have Such Tiny Arms?
As relentless a killing machine as T. Rex was, this dinosaur was still equipped with tiny, almost vestigial arms and hands. Why?

Sauroposeidon - About.com Dinosaurs
The North American Sauroposeidon was one of the tallest dinosaurs ever to walk the earth.

Saurophaganax - About.com Dinosaurs
The four-ton Saurophaganax is the official state dinosaur of Oklahoma.

Sauropelta - About.com Dinosaurs
Sauropelta is one of the best-known armored dinosaurs in the fossil record.

Sauroniops - About.com Dinosaurs
The name of this dinosaur, Sauroniops, means

Saurolophus - About.com Dinosaurs
Saurolophus is one of the few duck-billed dinosaurs known to have lived on two continents.

Sarcosaurus - About.com Dinosaurs
The

Santanaraptor - About.com Dinosaurs
The dinosaur Santanaraptor was named after Brazil's Santana Formation.

Saltasaurus - About.com Dinosaurs
The South American Saltasaurus was the first identified titanosaur dinosaur.

Saichania - About.com Dinosaurs
This dinosaur's name, Saichania, is Chinese for

Rugops - About.com Dinosaurs
The wrinkly-faced dinosaur Rugops probably fed on abandoned carcasses.

Rhinorex - About.com Dinosaurs
The duck-billed dinosaur Rhinorex had an unusually large nose.

Rapetosaurus - About.com Dinosaurs
Rapetosaurus is one of the few dinosaurs to be discovered in modern-day Madagascar.

Regaliceratops - About.com Dinosaurs
The North American dinosaur Regaliceratops had a huge, crown-shaped frill.

Raptorex - About.com Dinosaurs
The Asian dinosaur Raptorex was a pint-sized precursor of Tyrannosaurus Rex.

Rajasaurus - About.com Dinosaurs
The

Rahonavis - About.com Dinosaurs
Was the late Cretaceous Rahonavis a dinosaur-like bird, or a bird-like dinosaur?

Psittacosaurus - About.com Dinosaurs
The beak of the dinosaur Psittacosaurus wouldn't have looked out of place on a parrot.

Procompsognathus - About.com Dinosaurs
Was Procompsognathus an archosaur, or a very early dinosaur?

Pleurocoelus - About.com Dinosaurs
The sauropod Pleurocoelus was once the official state dinosaur of Texas.

Pinacosaurus - About.com Dinosaurs
Did the armored dinosaur Pinacosaurus roam central Asia in herds?

Pelorosaurus - About.com Dinosaurs
The

Pelecanimimus - About.com Dinosaurs
The

Pegomastax - About.com Dinosaurs
The strange dinosaur Pegomastax was covered with porcupine-like bristles.

Ozraptor - About.com Dinosaurs
Not much is known about the Australian dinosaur Ozraptor.

Pampadromaeus - About.com Dinosaurs
The

Paluxysaurus - About.com Dinosaurs
Paluxysaurus is a contender for the official state dinosaur of Texas.

Pachyrhinosaurus - About.com Dinosaurs
The

Ouranosaurus - About.com Dinosaurs
Scientists can't decide if the dinosaur Ouranosaurus had a sail or a hump.

Oryctodromeus - About.com Dinosaurs
Oryctodromeus is one of the few dinosaurs known to have lived in burrows.

Ornitholestes - About.com Dinosaurs
The

Nyasasaurus - About.com Dinosaurs
Could Nyasasaurus be the earliest dinosaur in the fossil record?

Nothronychus - About.com Dinosaurs
Nothronychus was the first therizonosaur dinosaur ever to be discovered outside Asia.