Dinosauria Online

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If you have any questions regarding specific words feel free to contact me via my email form and I will update the dictionary and send you a copy of the description for the word you inquired about.

Vocabulary Terms

AGE: No one knows for sure how old dinosaurs lived to be. Some scientists think they lived to a great age - possibly untill they were 100 or 200 years old. These scientists think that the huge dinosaurs may have continued to grow throughout their lives and that is why they got so large. Growth rings on dinosaur bones show that some were 120 years old when they died.

ANOMOEPUS (an-o-MEE-pus) "Different Foot" (Greek anomoios - different + pous = foot., because these footprints were different from others found in the same area)
Name given to Late Triassic or Early Jurassic dinosaur foot prints found in the Newark Basin of Connecticut, in Glen Canyon, Arizona, and in Europe. Both the three-toed hind FEET and five fingered forfeet left impressions, indicating the animal that made them was at least sometimes QUADRUPEDAL. Scientists believe the TRACKS were made by an ORNITHOPOD because there are no CLAW marks. When found, these tracks were important, because no ORNITHISCHIAN dinosaur bones and only a few isolated TEETH had been found in Triassic rock in North America. But now a recent discovery in Arizona has changed that. SCUTELLOSAURUS has been identified as a Late Triassic ornithischian.
Antarctic Dinosaurs The remains of several Cretaceous dinosaurs have been found in areas that lay below the Antarctic Circle whan they were alive. They were all small species. It is unknown whether this was because of the harsh climate or for some other reason. A small, unnamed ANKYLOSAURID was found on James Ross Island, Antarctica. It is too incomplete to be clearly identified but is important because it is the first ANKYLOSAURID found outside of GONDWANALAND.
FOSSILS of four dinosaurs were found in Victoria, Austialia, which was below the Antarctic Circle during the CRETACEOUS PERIOD. One was a small species of ALLOSAURUS only 7 feet (2 m) tall. The other three were HYPSILOPHODONTS: ATLASCOPCOSAURUS, FULGUROTHERIUM, and LEAELLYNASAURA. They were between 6.5 and 10 feet (2 and 3 m) long. Most are known from very scant material, but at least one had large, welldeveloped eyes and probably could see well in the dark.
Archosaurs or Archosauria (ahr-ko-SAWR-ee-ah) "Ruling Lizards" (Greek archos = ruler + sauros = lizard, because they were the dominant life form of the MESOZOIC ERA)
A subclass of REPTILIA ; a group of higher vertebrates (animals with backbones) including the CROCODILIANS, DINOSAURS, PTEROSAURS, and THECODONTS. Since birds are now thought to be descendants of dinosaurs, some scientists propose that Archosauria should be raised to class level and that it should include birds.
Armour Plating The bodies of ANKYLOSAURS were covered with rows of plates, or scutes, that were made of hard, bony material and keeled like the bottom of a boat. In the ANKYLOSAURIDAE these plates were oval and were hollowed out underneath, so they were relatively thin and light. Some rose to form low, pointed cones. These plates did not touch one another . the plates of the NODOSAURIDAE were thicker and heavier than those of the Ankylosauridae. They were solid and flat (or nearly flat) under neath. Some rose to form tall conical spikes. The plates, or scutes, of Nodosauridae contacted or touched each other and were rectangular or square in outline, rather than oval.
There is evidence that some ORNITHOPODS and some SAUROPODS (TITANOSAURIDS) had bony armor plates, similar to those of the ankylosaurids, attached to their SKIN.
STEGOSAURS had two rows of large, thin, leaf-shaped bony plates running down the middle of their backs. Although these were once thought to be DEFENSE mechanisms, it is now believed that they regulated body temperature. These plates contained blood vessels. Wind flowing across the plates would cool the blood flowing through the blood vessels.


Carnivore: (KAR-nih-vohr) Meat eater (Latin carn = flesh + vorare = to devour)
Any animal that eats mainly meat. Modern cats, dongs, and bears are carnivores. Carnivores have large, sharp teeth and powerful jaws. Some may, on occasion, eat plant food such as berries or grass. COELUROSAURS and CARNOSAURS were meat eating (carnivourous) dinosaur. Compare HERBIVORE; OMNIVORE.
Cretacious: (kreh-TAY-shus) Period (From Latin creta = chalk, referring to the chald deposits of southeast England, which are of this age)
The last of the three periods of the MESOZOIC ERA. It began about 135 million years ago and ended 65 million years ago. At the end of this geological time interval, the dinosaurs became EXTINCT.
Little is known about the dinosaurs of the first half of the Cretaceous Period. Not many exposed Ourcroppings of Early Cretaceous rocks containing FOSSILS have been found. It is in the Late Creteceous deposits that the most dinosaurs have been found.




Gastroliths (GAS-tro-liths) "stomach stones" (Greek gastros = stomach + lithos = stone)
Small, round stones used to grind FOOD in the gizzards or stomachs of some animals. (Modern birds swallow gravel for this purpose.) Gastroliths found near SAUROPOD FOSSILS have led scientists to speculate that these dinosaurs swallowed vegetation whole and ground it with gatroliths. (Sauropods had no molars.) This adaptation would have made it possible for sauropods to eat almost continuously and thus generate enough energy to sustain their huge bodies. Gastroliths have also been found in the fossilized stomachs of PLESIOSAURS.
(Q) We have been studying dinosaurs and want to know more about how the herbivores digested thier food. In particular, how the stones in their stomachs used to grind the food. How did the dinosaur get the stones to move?
(A) I will have to ask a professional theroist about the movement of the stones in the herbivores stomach. But my theory is that the movement of the herbivore itself from the sway of the creatures body and the erect tripod position to get at food in high trees moves the stones around and helps grind the food. Mainly for large quadraped dinosaurs. Same goes for the biped dinosaurs. Also they were in constant movement to evade their predators.
That is my theory I hope it helps

Herbivore: (HER-bih-vohr) "Plant Eater" (Latin herba = plant = vorare = to devour)
Any animal that eats mainly plants, such as modern cows or horses. There were many more plant eating (herbivourous) dinosaurs than meat eaters. All of the ORNITHISCHIAN dinosaurs and all of the SAUROPODOMORPHS were herbivours. Compare CARNIVOUR; OMNIVORE


Jurassic: (jer-ASS-ik) Period (Named for the Jura Mountains of France and Switzerland, because the rocks of those mountains are of that age)
The middle period of the MESOZOIC ERA. This grologica period began 190 million years ago and ended 135 million years ago.
Very little is known abou the dinosaur of Early Jurassic times bevause most rock formations of that age (that we know about) are marine sediments, and dinosaur were land animals. However, exciting new dinosaur discoveries that are of Early Jurassic age have been made in India. We may soon know much more about the dinosaurs of this age.
Many FOSSILS of Late Jurassic dinosaurs have been found. The largest of the dinosaurs (and the largest known land animals) lived during this period.



Mesozoic: (mez-o-ZO-ik) Era "Middle Life" (Greek mesos = middle + zoidos = life)
The "age of REPTILES", the geological period that followed thePALEOZOIC ERA and came before the CENOZOIC ERA. The Mesozoic began 225 million years ago and ended 65 million years ago. This was the era when the dinosaur ruled the earth. The Mesozoic is divided into three periods: the TRIASSIC, the JURASSIC, and the CRETACEOUS.


Opisthopubic (o-PISS-tho-pyu-bic) pelvis "Backward Pubis" (Greek opisthe = backward + Latin pubis = pubic bone)
A type of pelvis with a backwardly directed pubis as in those of ORNITHISCHIANS and birds. The ilium is broad and deep, more like those of SAURISCHIANS. view picture

Paliozoic: (pay-lee-o-ZOH-ik) Era "Ancient Life" (Greek palaios = ancient + zoikos = life)
The geological age preceding the MESOZOIC ERA. It bagan 600 million years ago and ended 225 million years ago. This is the period during twhich fish, sea plants, amphibians, land plants, and REPTILES developed.
Pangaea: (pan-JEE-ah) "All Earth" (Greek pan = all + gaia = earth)
The geological age preceding the MESOZOIC ERA. It began 600 million years ago and ended 225 million years ago. This is the period during which fish, sea plants, amphibians, land plants, and REPTILES developed.
Pterosaurs or Pterosauria: (tayr-o-SAWR-ee-ah) "Winged Lizards" (Greek pteron = wing + sauros = lizard, referring to its leathery wings)
Not DINOSAURS, but the order of winged ARCHOSAURS capable of flying or gliding. They are classed as FLYING REPTILES because of their very reptilian heads, teeth, and pelvises. Their hind feet were similar to those of dinosaurs of birds. Pterosaurs were lightly built, with hollow bones and small bodies. They had large brains, which suggests that they had good maneuverability when flying. They probably cold flap their wings slowly but may have relied upon thermal updrafts (uprising columns of warm air) or light breezes to get off the ground. The smallest pterosaurs were the size of sparrows, the largest were giants with 40 foot (12 m) wingspreads.
A pterosaur's wing was formed by a leathery membrane thta stretched from the side of its body to the tip of its fourth finger. This fourth finger was very long and supported the front edge of the wing. The other fingers were short and were equipped with sharp claws.
Pterosaurs probably had a poor sense of smell, and no doubt they relied on keen eyesight for hunting. Their eyes were ery large. Most were fish eaters, and they may have fished on the wing. Some had throat puches similar to those of modern pelicans. These probably fished from the surface of the seas. Some may have eaten insects. Still others had elongated, bristlelike teeth, resembling the baleen that modern whales use to strain plankton from seawatter. These pterosaurs may have eaten plankton.
Pteosaurs were probably ENDOTHERMIC (warm blooded). At least some are known to have had long, dense fur. Many had ridges or crests on their skulls. Some had long tils; others were tailless. Pterosaurs probably lived all over the world from Late Triassic through Late Cretaceous times. Two kinds are known. The RHAMPHORHYNCHOIDEA lived during the Triassic and JURASSIC PERIODS. They were small in size and had long tails. The PTERODACTYLOIDEA lived from Late Jurassic to Late Cretaceous times. They probably had no tails. Some had long bony crests. Some grew to be huge.




Triassic: (try-ASS-ik) Period (From Latin trias = triad, three, referring to the three successive series of rocks in Germany that are of this age)
The first of the three periods of the MESOZOIC ERA. This geological time period began 225 million years ago and ended 190 million years ago. Dinosaurs appeared in the middle of this period. Other major land animals of the period were amphibians and THERAPSIDS. The THECODONTS were the dominant life form. ICHTHYOSAURS and NOTHOSAURS inhabited the oceans. During the Late Triassic, the first mammals and earliest CROCODILIANS and turtles appeared.