HowStuffWorks Dinosaurs Guide  Tags: animal animals history howstuffworks dinosaur dinosaurs prehistoric fossil archaeology  

The recently discovered large theropod Abelisaurus comahuensis, from Patagonia, Argentina, looked a little like Albertosaurus from Alberta, Canada, particularly in its size and lifestyle. Find out more about the Late Cretaceous dinosaurs.

Acrocanthosaurus was a sauropod of spectacular proportions. In some ways it looked like many other meat-eating dinosaurs, but it had a sail along its back. See pictures and learn more about this dinosaur.

Albertosaurus was an older "cousin" to the better-known Tyrannosaurus.

Allosaurus was the most powerful, fearsome, and deadly dinosaur of the Late Jurassic. Until the Tyrannosaurus appeared this dinosaur was the largest predator to roam the Earth.

Archaepteryx was a very unique dinosaur in that it resembled a bird. It is known from only six fossils, but those fossils may be the most famous bones in the world. The Archaepteryx is the dinosaur that resembles modern birds the most.

This carnivorous dinosaur was named more than one hundred years ago for an unusual tooth found in the Judith River Badlands of northern Montana. When it was discovered, much of the West was still wild. Learn more about this Late Cretaceous dinosaur.

Baryonyx was found in 1983 by an amateur fossil collector in Surrey, England. He discovered a large claw that was nearly a foot long, and the animal was named for this fossil, which means "heavy claw." Learn more.

Carnotaurus (its name means "meat bull") is known from a single, nearly complete skeleton that had skin impressions over much of the skull and body. Read more about this South American dinosaur's unusual features.

Ceratosaurus was perhaps the greatest rival of the Allosaurus. It had a huge head with powerful jaws, and a massive body. It also had powerful legs which allowed it to run at high speeds.

One of the most unusual predators is that of Coelophysis. It was only slightly larger than a turkey and had a long slender tail and a mouth full of knife-edged teeth. What was this dinosaur's behavior like?

The Compsognathus was one of the smallest known dinosaurs, which is amazing considering that it was a meat-eating dinosaur. This animal was about the size of a turkey and lived mostly near water. What else do we know about this dinosaur?

The oviraptorids were peculiar theropods. Smallish, bipedal animals with strong beaks, they may have fed on mollusks by crushing their shells to get the soft meat inside. Learn more about the Conchoraptor, an oviraptorid, and other Late Cretaceous dinosau

With its massive head and large teeth, there is no question that Daspletosaurus was master of its world. It got its name because of its ferociousness; its name means "frightful reptile."

Though Deinonychus was small compared to Tyrannosaurus or Allosaurus, it was an agile theropod capable of deadly attacks. Nearly complete skeletons of this fierce dinosaur were discovered in southern Montana in 1964. Learn more.

A recently named armored dinosaur, Denversaurus is based on a badly crushed skull from South Dakota. No other parts of the skeleton have been found, so it is difficult to estimate how long or heavy the animal was. Learn more about the Denversaurus.

Often called the terror of the Early Jurassic, the Dilophosaurus was a fast and agile dinosaur with extremely powerful neck and jaw muscles. It also had two crests on its head that may have been used for displaying the animal's social position.

In 1914, Barnum Brown of the American Museum of Natural History collected a nine-inch-long skull and some foot bones from the Judith River Formation in Alberta. It was named Dromaeosaurus, which means "running reptile." Learn more about the Dromaeosaurus.

Dromiceiomimus ("emu mimic") has been found both in the Late Cretaceous Horseshoe Canyon and the Judith River Formation of Alberta. It is very similar to Struthiomimus and Ornithomimus, but had much larger eyes and longer, more slender arms.

Dryptosaurus is the only carnivorous dinosaur from the East Coast of the United States based on more than a single bone. The partial skeleton was discovered more than a hundred years ago by workers in a quarry in New Jersey.

Named after the flying mythical Greek creatures called Harpies that snatched victims with their hands, Harpymimus ("snatcher mimic") is the most primitive ornithomimid known. Learn more about the Harpymimus and other Late Cretaceous dinosaurs.

The Herrerasaurus was a large dinosaur that weighed about 400 pounds and was about 10 feet long. It survived on a diet of small animals which it most likely caught by ambush and surprise. What else is known about this dinosaur?

The first remains of Hypsilophodon were discovered in 1849 from Early Cretaceous rocks on the Isle of Wight, England. They were long-legged, swift and agile. Scientists even thought they might have lived in trees. See why.