Dinosaur Facts
 

Dinosaur Shapes and Sizes

Dinosaurs varied greatly in size and shape, ranging from the giant Apatosaurus, which grew to lengths of 24 m (80 ft), to the Compsognathus, a small predator about 60 cm (2 ft) tall, or about the same size as a modern-day goose.
 

Origins of the Dinosaurs

Reptiles commonly known as dinosaurs dominated the earth from the end of the Triassic Period, 205 million years ago, to the end of the Cretaceous Period, about 65 million years ago. Only four descendant orders exist to the present day: the Squamata, which includes lizards and snakes; the Chelonia, which includes turtles and tortoises; the Crocodilia, which includes crocodiles, alligators, caimans, and gavials; and the Rhynchocephalia, which includes only one member, the tuatara, often called a living fossil.
 

TUOJIANGOSAURUS

The Chinese stegosaur, Tuojiangosaurus, was an enormous plant eater with one of the smallest brains of any of the dinosaurs. Although the large plates along the ridge of its back look like a defense against larger predators, it is more likely that they helped to cool the stegosaur by dissipating heat, much like a radiator.

Dorling Kindersley

 

Parasaurolophus Skull

The elongated, crested skull of the male Parasaurolophus has been the topic of debate among paleontologists for years. The elongated extension of the top of the skull may have acted as a resonator, enhancing the call of this plant-eating dinosaur and enabling it to attract a mate or warn others of impending danger. The skull pictured here faces right.

Dorling Kindersley

 

 

STYRACOSAURUS
"Spiked lizard"
Styracosaurus Printout

ANATOMY
Styracosaurus was a dinosaur that walked on four short legs. This large plant-eater had a six-spiked frill projecting from the back of its skull. It also had an upward-pointing horn on its nose (2 feet (60 cm) long and 6 inches (15 cm) wide), and two small horns above its eyes. These spikes and the horn probably provided protection from predators, and were possibly used in mating rituals and rivalry. It had a short, thick, pointed tail, a large, bulky body, a large skull and a beak. Styracosaurus hatched from eggs.

Styracosaurus was about 18 feet (5 m) long, 6 feet (1.8 m) tall, and weighed up to 3 tons.

WHEN STYRACOSAURUS LIVED
Styracosaurus lived in the late Cretaceous period, about 77-70 million years ago. It was among the last of the dinosaur species to evolve before the Cretaceous-Tertiary extinction 65 million years ago. Among the contemporaries of Styracosaurus were Tyrannosaurus rex, Ankylosaurus (an armored herbivore), Corythosaurus (a crested dinosaur), and Dryptosaurus (a meat-eating dinosaur).

BEHAVIOR
Styracosaurus may have been a herding animal, like some other ceratopsians. This hypothesis is supported by the finding of bone beds, large deposits of bones of the same species in an area. Styracosaurus hatched from eggs, and the young may have been cared for by parents.

When threatened by predators, Styracosaurus may have charged into its enemy like a modern-day rhinoceros does. This would have been a very effective defense.

INTELLIGENCE
Styracosaurus was a ceratopsian, whose intelligence (as measured by its relative brain to body weight, or EQ) was intermediate among the dinosaurs.

DIET
Styracosaurus probably ate cycads, palms, and other prehistoric plants with its tough beak. It could also chew well with its cheek teeth (like other ceratopsians, but unlike most other dinosaurs).
t; color: red">LOCOMOTION

Styracosaurus walked on four short legs; it may have been a relatively fast dinosaur, perhaps running at up to 20 mph (32 kph). Dinosaur speeds are estimated using their morphology (characteristics like leg length and estimated body mass) and fossilized trackways.

DISCOVERY OF FOSSILS
Styracosaurus was named in 1913 by L. M. Lambe from a fossil found near Alberta, Canada. Fossils have been found in the USA and Canada. A bonebed of about 100 Styracosaurus fossils was found in Arizona, USA, indicating that they travelled in herds.

CLASSIFICATION
Styracosaurus was a late ornithischian dinosaur, the order of bird-hipped, herbivorous dinosaurs. It was a member of the suborder Marginocephalia, and of the family of large, horned, frilled, herding herbivores, the ceratopsians. The ceratopsians were one of the last major groups of dinosaurs to evolve, and include Psittacosaurus, Leptoceratops, Pachyrhinosaurus, Montanoceratops, Chasmosaurus, Centrosaurus, Triceratops, Styracosaurus, Protoceratops, and others.

Click here for information on the styracosaurus

 

PARASAUROLOPHUS
"Beside Saurolophus (Crested Lizard)"

Activities and Printouts

Click here to find additional information on the parasaurolophus

 

STEGOSAURUS
"Covered Lizard" or "Roof Lizard"

Activities and Printouts

  • Plant eater
  • Very small head with a tiny brain and toothless beak
  • Large, flat, bony, triangular plates along its back
  • A heavy, spiked tail for protection
  • Walked on four legs, but the back legs were twice as long as its front legs

Click here for information on the stegosaurus

 

Apatosaurus/Brontosaurus Fact Sheet
Go to a Printable Version


Dinosaur/Paleontology Dictionary

 

NAME:

Meaning - Apatosaurus means "deceptive lizard" - Brontosaurus (this name is no longer used) means "thunder lizard"
Pronounced - a-PAT-o-SAWR-us
Named By - Othniel C. Marsh
When Named - 1877

DIET:

Herbivore (plant-eater). Apatosaurus swallowed stones to help grind up its tough plant food. It did not chew its food.

SIZE:

Length - 70-90 feet (21-27 m) long
Height - 10-15 feet (3-4.6 m) tall at the hips
Weight - 33-38 tons (30-35 tonnes)

WHEN IT LIVED:

Late Jurassic period, about 157-146 million years ago

WHERE IT LIVED:

Fossils have been found in Colorado, Oklahoma, Utah, and Wyoming, in the USA, North America.

FOSSILS:

A few incomplete fossils have been found (mostly without skulls).

CLASSIFICATION:

  • Kingdom Animalia (animals)
  • Phylum Chordata (having a hollow nerve chord ending in a brain)
  • Class Archosauria (diapsids with socket-set teeth, etc.)
  • Order Saurischia - lizard-hipped dinosaurs
  • Suborder Sauropoda - large, long-necked, quadrupedal herbivores
  • Superfamily Neosauropoda - advanced sauropods
  • Family Diplodocidae - whip-tailed, peg-toothed sauropods with high spines on the vertebrae.
  • Genus Apatosaurus
  • Species A. ajax (type species named by Marsh, 1877)

INTERESTING
FACTS:

The dinosaur Brontosaurus (Marsh,1879) is now called Apatosaurus. Apatosaurus' nostrils were located on the top of its head.

LINKS:

A detailed page on Apatosaurus/Brontosaurus.

Click here for information on the Apatosaurus

 

Pteranodon Fact Sheet
Go to a Printable Version


Dinosaur/Paleontology Dictionary

NAME:

Meaning - Pteranodon means "Winged and Toothless"
Pronounced - ter-AN-o-DON
Named By - Othniel C. Marsh
When Named - 1876

DIET:

Carnivore (meat-eater) - Pteranodon probably ate mostly fish

SIZE:

Wingspan - 25-33 foot (7.8-10 m) long
Standing Height - 6 ft (1.8 m) tall at the hips
Weight - 55 pounds (25 kg)

WHEN IT LIVED:

Late Cretaceous period, about 85-75 million years ago.

WHERE IT LIVED:

Fossils have been found in Kansas, USA, North America and in England, Europe.

FOSSILS:

Many Pteranodon fossils have been found. The first Pteranodon skull was found on May 2, 1876, in Smoky Hill River, Wallace County, Kansas, USA, by S. W. Williston, a fossil collector working for Othniel Marsh.

CLASSIFICATION:

  • Kingdom Animalia (animals)
  • Phylum Chordata (having a hollow nerve chord ending in a brain)
  • Superclass Tetrapoda (four-legged animals)
  • Class Archosauria (diapsids with socket-set teeth, etc.)
  • Order Pterosauria - (flying reptiles)
  • Suborder Pterodactyloidea ("wing finger") - later pterosaurs that appeared late in the Jurassic and died in the K-T extinction, 65 million years ago. They had short tails. Examples include Pterodactylus, Pteranodon, and Quetzalcoatlus.
  • Family Pteranodontidae
  • Genus Pteranodon
  • Species P. longiceps (type species named by Othniel C. Marsh, 1876)

INTERESTING
FACTS:

Pteranodon was a flying reptile that lived during the time of the dinosaurs - it was not a dinosaur, but was a close relative of the dinosaurs. Pteranodon's wing-span is longer than that of any known bird. It had a crest on its head, no teeth at all, and a very short tail.

LINKS:

A detailed page on Pteranodon.

A coloring/information printout on Pteranodon.

 

Protoceratops
"First Horned Face"

Protoceratops printout
K-3 Protoceratops printout

ANATOMY
Protoceratops walked on four legs, had a large head, a bulky body, a parrot-like beak, cheek teeth, and a small frill on its head. Males may have had larger frills than females, indicating that the frill may have been used in courtship and mating.

Protoceratops was about 6 to 8.2 feet (1.5-2.5 m) and weighed roughly 900 pounds (400 kg). It was about 3 feet tall ( to the top of the shoulders).

WHEN PROTOCERATOPS LIVED
Protoceratops lived in the late Cretaceous period, about 86 to 71 million years ago, toward the end of the Mesozoic, the Age of Reptiles.

BEHAVIOR
Protoceratops was probably a herding animal, like some other ceratopsians. This hypothesis is supported by the finding of bone beds, large deposits of bones of the same species in an area, and large groups of nests. Each nest had 12 or more eggs, laid in a spiral fashion.

Sexual dimorphism (the physical differences between the sexes) in frill size has also been noted, with males may have had larger frills than females, indicating that the frill may have been used in courtship and mating (P. Dodson, 1976, Journal of Paleontology).

INTELLIGENCE
Protoceratops was a ceratopsian, whose intelligence (as measured by its relative brain to body weight, or EQ) was intermediate among the dinosaurs.

DIET
Protoceratops was an herbivore, a plant eater. It probably ate cycads and other prehistoric plants with its tough, hook-like beak.

LOCOMOTION
Protoceratops walked on four short legs; it was a relatively slow dinosaur. Dinosaur speeds are estimated using their morphology (characteristics like leg length and estimated body mass) and fossilized trackways.

DISCOVERY OF FOSSILS
Protoceratops was first discovered in the Gobi Desert in Mongolia in the 1920's. It was named by Walter Granger and W. K. Gregory.

Numerous fossils have been found, from eggs in nests to juvenile to mature specimens. Sexual dimorphism (the physical differences between the sexes) in frill size has also been noted, with the adult male possibly having a more pronounced frill than the adult female.

A fossil of Protoceratops has been found with one of a Velociraptor; the Velociraptor had been attacking the Proroceratops, which had butted in the chest of the Velociraptor.

CLASSIFICATION
Protoceratops was an ornithischian dinosaur, the order of bird-hipped, herbivorous dinosaurs. It was a Ceratopsian ( a suborder of frilled, herding herbivores, that include Triceratops, Styracosaurus, etc.), and a Protoceratopsid (an early ceratopsian, which included Montanoceratops, Leptoceratops, and others).

PROTOCERATOPS LINKS
Protoceratops printout

K-3 Protoceratops printout to color

American Museum of Natural History: Protoceratops

 

TUOJIANGOSAURUS

(pronounced Too-oh-gee-ANG-oh-SAWR-us) A stegosaurid, a quadrupedal, plant-eating dinosaur about 23 feet (7 m) long with double rows of plates along its back, a toothless beak, a long, low-hanging head, spoon-shaped teeth, 2 shoulder spikes, and a 4-spiked tail. It was from the late Jurassic period, about 163-150 million years ago in China. It was named in 1977 by Shiwu Zhou, Dong, Zhang, and Li.

 

Tyrannosaurus rex
the "Tyrant lizard king"

T. rex was a huge meat-eating dinosaur that lived during the late Cretaceous period, about 85 million to 65 million years ago. T. rex lived in a humid, semi-tropical environment, in open forests with nearby rivers and in coastal forested swamps. The seasons were mild.

Until recently, Tyrannosaurus rex was the biggest known carnivorous dinosaur; Giganotosaurus and Carcharodontosaurus are slightly bigger.

ANATOMY
Tyrannosaurus rex was a fierce predator that walked on two powerful legs. This meat-eater had a huge head with large, pointed, replaceable teeth and well-developed jaw muscles. It had tiny arms, each with two fingers. Each bird-like foot had three large toes, all equipped with claws (plus a little dewclaw on a tiny, vestigial fourth toe). T. rex had a slim, stiff, pointed tail that provided balance and allowed quick turns while running. T. rex's neck was short and muscular. Its body was solidly built but its bones were hollow.

SIZE
Tyrannosaurus rex was up to 40 feet (12.4 m) long, about 15 to 20 feet (4.6 to 6 m) tall. The arms were only about 3 feet (1 m) long. Tyrannosaurus rex was roughly 5 to 7 tons in weight.

The enormous skull was about 5 feet (1.5 m) long. The eye sockets in the skull are 4 inches (10.2 cm) across; the eyeballs would have been about 3 inches (7.6 cm) in diameter.

T. rex left footprints 1.55 feet (46 cm) long (although its feet were much longer, about 3.3 feet (1 m) long; T. rex, like other dinosaurs walked on its toes). It had a stride length of up to 12 to 15 feet (3.7-4.6 m). T. rex may have run at up to 15 mph (24 kph).

TEETH AND JAWS

T. rex's jaws were up to 4 feet (1.2 m) long and had 50 to 60 thick, conical, bone-crunching teeth that ranged in size from very small to over 9 inches (23 cm) long. Adult had a variety of sizes of teeth in their jaws at one time, as teeth were broken and new (smaller) ones grew in to replace them. One T. rex was found with some teeth up to 13 inch (33 cm) long. T. rex could eat up to 500 pounds (230 kg) of meat and bones in one bite!

Tyrannosaurus rex had a wrap-around overbite; when T. rex closed its mouth, the upper parts of the lower jaw's teeth fit inside the upper teeth.

SKIN
Fossilized specimens of T. rex's rough, scaly skin have been found. It was bumpy, like an alligator's skin, and has been described as a "lightly pebbled skin."

HABITAT AND DISTRIBUTION
Tyrannosaurus rex probably lived in forests, where its prey (plant-eating dinosaurs) could find plenty of food. T. rex fossils have been found in western North America and Mongolia.

SENSES
Sight: T. rex had large visual lobes in its brain that processed visual information. T. rex also had depth perception (since both eyes faced forwards on the front of its skull, and not placed on the sides), but it was not the only dinosaur that had depth perception. In general, predators (hunters) ofter have depth perception to help them hunt their prey. Animals that are hunted (like the plant-eating dinosaurs) usually have eyes located on the sides of their head (having no depth perception); this lets them see predators approaching from both sides.

Smell: T. rex's brain had a very large area in the brain for processing odors.

TAIL
Tyrannosaurus had a stiff, pointed tail (like other Tetanurans [meaning "stiff tail"]). The tail was used as a counterbalance for its enormous head, for agility and for making quick turns.

The rear part of the tail was stiffened by interlocking vertebral zygopophyses (interlocking bony structures projecting forwards and backwards from the neural arches, interlocking one vertebra into another).

OTHER HUGE MEAT-EATING DINOSAURS
Although not the biggest meat-eating dinosaur ever discovered, Tyrannosaurus rex was certainly one of the largest terrestrial carnivores of all time. The recently discovered Giganotosaurus carolinii and Carcharodontosaurus may have been even more enormous.

SIZE COMPARISONS

PRINTOUTS
A Tyrannosaurus rex printout.

A simple T. rex printout.

A T. rex skeleton printout.

Dinosaur footprint

Why T. rex's weren't great boxers.