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Compsognathus: Compsognathus
was a bird-like dinosaur that walked on two long, thin legs; it had three-toed feet. A long tail acted as a counterbalance
and for stability during fast turns. It had short arms with two clawed fingers on each hand. Compsognathus had a small, pointed
head with small, sharp teeth, hollow bones, and a long, flexible neck. Compsognathus was about the size of a chicken. Its
femur (thigh bone) was only 4. 3 inches long. Compsognathus was a carnivore
that caught and ate small animals, including insects and lizards. John Ostrom found fossilized remains from a Compsognathus'
stomach that contained the skeleton of the fast-running lizard Bavarisaurus. In the movie The Lost World, compsognathids
are said to have venom to slow prey and it showed them hunting in packs; there is no evidence for this. Compsognathus walked on two long, slender legs; it was a fast, agile dinosaur. Dinosaur speeds are estimated using their morphology (characteristics like leg length and estimated
body mass) and fossilized trackways.
Corythosaurus: Corythosaurus, one of
the best known dinosaurs, is the Corinthian helmet reptile because of the large crest atop its head. As depicted in both children
and adult literature alike, this dinosaur is stunning and dazzling, its body in perfect form and beautiful to the mind. Its
design is extravagant and well-made. The
crest sits atop its head above the eyes, rising up into an arch then back down again to the base of the skull and the top
of the neck. The crest was different shapes and sizes, depending on the dinosaurs sex, at maturity. The crest, like many of
the crests on other dinosaurs, contains a nasal passage. Air was sucked up into the crest, where it flowed through tunnel-like
chambers and went into side pockets, where it then combined in a common chamber within the crest. From there it went down
the throat and into the lungs. While for breathing, it might have been able to produce sound; it is designed much like modern-day
wind and bass musical instruments. Of course, the sound would have been very low and maybe even a deep trumpet-like blare.
The sounds might have been used to call to offspring or other members of its species. Other possibilities for such sound passages
is that the sound was used to signal water or food, other resources, or warn of impending danger (such as a Tyrannosaurus
nearby).
Deinonychus: Frightening
and compelling, this dromaeosaur once held the record for popularity above Velociraptor, but when the smash Box-office
hit Jurassic Park was released, it was forgotten to its smaller and less menacing partner. And while the Velociraptor
in Jurassic Park is closer in appearance and performance to Deinonychus, Deinonychus will forever be
scarred, its name tainted. But only to the uneducated. While
smaller and not as strong as the larger theropods like Tyrannosaurus, Gorgosaurus or Allosaurus, either
as a loner or a pack hunter, either way, it was still capable of horrifying and ghastly attacks. Deinonychus was most likely a pack
hunter, taking down large prey while coordinating their efforts. They were powerful, bristling with muscles, the terrors of
their times. A large head rest upon their shoulders, with gruesome teeth arching back towards the back of the mouth; these
backward-facing teeth helped to hold strangling prey and to rip flesh off food. Long arms dangled down, each with a three-fingered
hand, each finger ending in a bloodcurdling, nasty claw. The fingers were flexible, showing that they were probably used to
attack and eat fallen victims. The femur (thigh bone) is smaller than the shin bones (tibia and fibula), which is common among
Dromaeosaurids, indicating a knack for awesomely fast speed. The back feetthe ones which were used for walkingare tridactyl,
which means the carnivore walked on only three toes. One of the features that
is so memorable from the movie Jurassic Park and a hallmark for contemporary dinosaurs is the slashing claw on each
foot. Sickly, large, and sharply-pointed, it curved in an arch and was held off the ground while running/walking to protect
it from wear and tear. This claw could be flicked easily, tearing into flesh while ripping back; a good swipe into the gut,
then a rip, could spill the innards of any animal. Other Dromaeosaurids had this feature, such as the famed Velociraptor
and Dromaeosaurus. Thin rods of bone ran along the vertebrae of the tail,
holding it stiff off the ground. However, where the tail connects to the body, it is flexible, allowing for it to sway up,
down, right or left, in whatever direction, to help balance the animal during daily life or even a vicious assault. Deinonychus might have hunted in packs. One very important discovery was the remains
of several Deinonychus and a single Tenontosaurus, tangled together in the grip of desperate battle. This remarkable
find is a powerful slab of evidence stacked in the favor of Deinonychus hunting in packs, in this case working together
to take down a Tenontosaurus. Deinonychus might have grasped its prey with its hand claws and slashed at the
underbelly with its curved, ghastly foot claw. There would be more success of bringing down large prey if hunting together
rather than in packs. 3 nearly complete fossil skeletons were found in southern Montana in 1964; now Deinonychus is one of the best-known
Dromaeosaurids. John Ostrom studied Deinonychus; at the time, the theropod classification table was divided into two
groups, the Carnosauria and the Coelosauria. Deinonychus had features found in both groups; this showed that the current
classification table wasnt completely reliable, and it was later remodeled.
Dilophosaurus: Dilophosaurus was a speedy, slender, bipedal
meat-eater. It was a theropod about 20 feet long, about 5 feet tall at the hip, and weighing about 650 to 1,000 pounds. It
had two thin, bony, almost semi-circular crests on its head; these may have been for mating displays. It is hard to imagine
how this crest wouldnt have been damaged during feeding into the carcasses; with such frailty, it would be more reasonable
that Dilophosaurus was an herbivore, who used its sharp claws and sharp teeth to find and eat tough plants. But after
the Fall, it very reasonably might have gone carnivorous, as was the trend. It
had short arms with three-fingered hands and strong legs with four-toed feet (one toe was a dewclaw). Both fingers and toes
had claws. It had hollow bones and an S-shaped, curved neck. Dilophosaurus may have roved in packs, since three specimens
were found together in Arizona, USA. Dilophosaurus was a carnivore, a
meat eater. It had loosely attached jaws which would have made killing animals with its teeth difficult. It must have killed
with its clawed arms and legs, and/or scavenged carcasses. Dilophosaurus
walked on two muscular legs and was a relatively fast runner, leaving bird-like footprints on land. Some of its fossilized
footprints are only impressions of the claw-tips. This indicates that Dilophosaurus may have been walking in water at the
time.
Diplodocus: Eleven complete skeletons of Diplodocus, eleven
copies were made, and they were sent to hundreds of museums all over the world. For years it was considered the longest dinosaur
(with its long neck and very long, whip-like tail). But other finds of sauropods have discounted this belief, such as the
gigantic Ultrasaurus. But Diplodocus was in no way small! However,
compared to its body, the animals head was small and horse-like. Peg-like teeth rested in the front of the mouth, used to
strip a lot of leaves from trees. The leaves were then swallowed, carries down the humongous esophagus, and once in the stomach
mashed to a pulp by gastroliths. The tail was extremely long, adding to
the amazing 90-foot length of this beast. The last third of the tail was thin and whip-like; it was able to be more flexible
and smaller because the vertebrae at the end of the tail were reduced to simple rods, not as complex as the vertebrae throughout
the rest of the dinosaur. Diplodocus front legs were shorter
than the back legs. The hips were higher than the shoulders because of this, and so it arched forward towards the head. With
the awesome size and strength of the back legs, this sauropod might have reared up on its back legs to eat off trees, but
a similar but different idea holds the sway of scientific opinion: rearing up on its back legs, it would probably merely just
push down trees with its gut-wrenching weight, then eat the trees as they lie on the ground. Why this idea? Simply because
there would be blood pressure problems on the neck and the rest of the body down to the legs if Diplodocus reared up
for long periods of times eating off the tops of trees. The chevronsbones
on the underside of the taillook like side-on Ts in Diplodocus. Most other dinosaurs have V-shaped chevrons, making
Diplodocus rather unique in this area. How did Diplodocus hold
up its tail, which measured half its body length? Huge tendons in the tail ran from the back of the head to the tip of the
tail, balancing the tail against the weight of the neck, allowing both the neck and tail to be held straight out at the same
time! This is a clear case of excellent design created by the ultimate CreatorGod!
Dromaeosaurus: The famous dinosaur from Jurassic Park is
unmentionably the
Velociraptor.
But yet there is another raptor that is just as terrible, and maybe even more so. That beast is Dromaeosaurus. Dromaeosaurus
is similar to Deinonychus and Velociraptor, in the fact that they all belong to the same classification group
and all share a single grisly feature: a sickle-shaped, huge claw on the foot. Dromaeosaurus
is a small, bird-like predator. A switch-blade-like claw on each foot, held up off the ground while running, was used to slash
out at prey; this claw could deliver bleeding, savage tears and even open the bowels in a furious assault. The extremely swift tail was nearly inflexible! Bony rods on the vertebrae that were
lengthened caused inflexibility. In dinosaurs belonging to the classification group Dromaeosauridaesuch as Velociraptor,
Deinonychus and Dromaeosaurushad bony rods greatly lengthened, spanning over several vertebrae to keep the tail
incredibly stiff, which helped them with balance while hunting, attacking or just walking around. Dromaeosaurus probably hunted in groups because of the small size, and because fossil
remains show several Deinonychuswhich is a Dromaeosaurid, such as Dromaeosaurustaking down a lone Tenontosaurus.
Dryosaurus: Ornithopods relied on agility and speed, not size, armor
or bodily weaponssuch as spikes, clubs or hornsto defend themselves. Dryosaurus, being a typical ornithopod, was no
exception. Dryosaurus is certainly one of the best-understood dinosaurs in existence. Dryosaurus stood and ran on its hind legs; the feet were well-designed for speedy running. It is estimated that
Dryosaurus could reach a speed of up to 25 mphfast enough to outrun most predators! It kept its balance while running
via its relatively long tail; the tail acted as a counterbalance to keep it from toppling over. This dinosaur has been shown by analysis of bone tissue of babies, juveniles and adult Dryosaurs to be a speedy
grower. There is no sign in remains that its growth slowed during the seasons, as is typical with most reptiles. Some scientists
say only warm-blooded animals can grow continuously, and so therefore add weight to the idea that Dryosaurusand possibly
all dinosaurswas warm-blooded. Its cheek teeth were thickly enameled, able to grind up plant
matter without pausing. It chopped food with a sharp, horny beak at the front of the mouth; the beak allowed no room for teeth
in the front of the mouth.
Edmontosaurus:
Edmontosaurus was a large, plant-eating, duck-billed dinosaur. It had short arms,
a long, pointed tail, three-toed, hoofed feet, and mitten-like hands. Its head was flat and sloping with a wide, toothless
beak, cheek pouches, and hundreds of closely packed cheek teeth that ground up its food. It was a biped that could also walk
on four legs, perhaps to graze low-lying plants. Edmontosaurus was a slow-moving dinosaur with few defenses, but may have
had keen senses to help it avoid predators. Edmontosaurus had leathery
skin (as determined from two mummified Edmontosaurus fossils found in Wyoming). It may have had loose skin around its nose
area - some paleontologists think that it may have been able to blow up this skin like a balloon, perhaps for mating rituals
or intra-species rivalry, as some birds do. It had a series of bumps (tubercles) running along its neck, back, and tail. Edmontosaurus
was an ornithopod, whose intelligence (as measured by its relative brain to body weight, or EQ) was midway among the dinosaurs.
Edmontosaurus probably lived in herds (like many other hadrosaurs) since
large numbers of Edmontosaurus have been found close to one another in Alberta, Canada. Edmontosaurus herds may have migrated
thousands of miles seasonally, traveling from the North Slope of Alaska (which would have been dark for months at a time during
winter, making plants scarce) to Alberta, Canada (which was rich in green plants during winter). Large numbers of Edmontosaurus
fossils have been found at both ends of this proposed migratory route. Edmontosaurus
was an herbivore, a plant eater. Fossilized conifer needles have been found in Edmontosaurus' stomach. It ate conifer needles,
twigs, seeds, and other plant material with its tough beak. It had no teeth in its beak, but had hundreds of cheek teeth used
for grinding up tough plant material.
Eoraptor: Eoraptor was a bipedal predator, running mainly
on its hind limbs, possibly walking on all fours from time to time. The five-fingered hands were designed for grasping, the
fifth finger very small. The bones in its limbs were thin-walled and hollow, reducing the weight of the dinosaur. Each foot
had five toes, and unlike other theropods, the first toe might have supported the dinosaur when walking. Serrated teeth and
the grasping hands indicate it was a carnivore, capable of handling prey nearly as big as itself; but the main diet likely
consisted of mainly lizards, rodents and other small animals, even insects. Eoraptor was a small, agile, quick dinosaur,
a threatening danger to anything at or below its size.
Euhelopus: Euhelopus is a large sauropod that was found in China.
Similarly resembling the North American Camarasaurus, it was long
and slender, and had extra vertebrae in the neck. Its skull had a long snout, unlike the round head of Camarasaurus, and
ate food from the treetops. The skull weighed approximately 15-20 pounds.
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