Theropods

Acrocanthosaurus: Acrocanthosaurus (meaning "high-spine lizard" because of the spikes growing out of its spine) was a fierce predator that was roughly 30-40 feet (9-12 m) long and weighed about 5,000 pounds (2300 kg). It had a big head, with a 4.5 foot (1.4 m) long skull and 68 thin, sharp, serrated teeth. It had 17-inch (43 cm) spikes extending from its vertebrae, along the neck and tail that may have formed a thick, fleshy sail on its back. It had powerful arms, and each hand had three fingers, equipped with long, sickle-like claws. Acrocanthosaurus lived during the early Cretaceous period, roughly 115-105 million years ago, in the tropics near sea level.

Albertosaurus:
Albertosaurus was a relative of Tyrannosaurus rex; Albertosaurus was smaller than T. rex and lived a few million years earlier. Albertosaurus walked on two legs and had a large head with sharp, saw-toothed teeth. It had two-fingered hands on short arms. Its long tail provided balance and quick turning. It had powerful back legs with clawed, three-toed feet. Albertosaurus was about 30 feet (9 m) long, about 11 feet (3.4 m) tall at the hips, and up to 3 tons in weight (averaging roughly 2500 kg). The lower jaw of Albertosaurus had from 14 and 16 teeth; the upper jaw had 17-19 teeth. It had one row of teeth in each jaw but had at least one replacement tooth growing up from under each tooth.Albertosaurus lived in the late Cretaceous period, about 76-74 million years ago, toward the end of the Mesozoic; the Age of Reptiles.Albertosaurus was a carnivore (a meat eater). It probably ate plant-eating dinosaurs.

Allosaurus:
Allosaurus was a large, meat-eating dinosaur. It was the biggest meat-eater in North America during the late Jurassic period.
Allosaurus was the biggest meat-eater during the late Jurassic period, about 154 to 144 million years ago.Allosaurus was a huge carnivore, a meat eater equipped with sharp, pointed teeth in large, powerful jaws - it was the biggest meat-eater in its habitat. This theropod also had long, sharp clawed hands. Allosaurus probably ate large, plant-eating dinosaurs, like Stegosaurus.

Baryonyx:
Baryonyx means heavy claw was an unusual theropod with huge 1-foot (30.5-cm) long claws on its hands, and long, narrow, crocodile-like jaws with 96 small, serrated teeth (this is 1.5 times the number of teeth that most other theropods had). It had a small crest on its snout. Baryonyx had a long, straight neck (unlike other theropods, which had s-shaped necks) and a long tail. Its low-slung body was supported by 2 large rear legs and 2 slightly smaller arms. It was a carnivorous dinosaur from the early Cretaceous period, about 125 million years ago. This predator was about 32 feet (9.5 m) long, weighing perhaps over 2 tons.Baryonyx lived during the early Cretaceous period, about 125 million years ago, in what is now England. Baryonyx was a carnivore, a meat eater with huge claws and many small, sharp teeth in powerful, crocodile-like jaws. It had 64 teeth in the lower jaw but only 32 teeth in the upper jaw (the upper teeth were larger than the lower teeth). Baryonyx was a large predator that ate fish. A fossilized Baryonyx was found with a fossilized meal in its stomach; this stomach contained fish scales, fish bones, and some partially digested bones of a young Iguanodon. So far, Baryonyx is the only known dinosaur that ate fish. It may have waded in rivers and shallow seas to catch fish (just as some modern-day bears do).

Carcharodontosaurus:
Carcharodontosaurus was a huge meat eater from the Cretaceous period. This North African carnosaur had a massive tail, a bulky body, and heavy bones. Its arms were short and had three-fingered hands with sharp claws. Carcharodontosaurus was from 26-44 feet long (8-14 m), perhaps weighing up to 8 tons. It had a skull that was as big as a person - 5'4" (1.6 m). It had large, powerful jaws with long, serrated, sharp teeth up to 8 inches long. Although Carcharodontosaurus was larger than T. rex, its brain was smaller. Carcharodontosaurus was closely related to Giganotosaurus but not to T. rex. Carcharodontosaurus was a more primitive dinosaur than T. rex. Carcharodontosaurus lived in the Cretaceous period, about 110 to 90 million years ago. Carcharodontosaurus was a carnivore, a meat eater. It was a large, fierce predator that could kill even large sauropods. Carcharodontosaurus may also have been a scavenger.

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