Page 92 - DINOSOUR ATLAS

glossary

iChthyosAur ornithomimid sediment
A sleek, fast-swimming reptile, similar in A fast-running, meat-eating dinosaur with a Tiny particles of sand, silt, and clay, deposited
appearance to a dolphin. long neck and slender legs, similar in appearance in layers by wind, water, or ice.
to a present-day ostrich.
iGuAnodont speCies
A plant-eating dinosaur with hooflike nails ornithopod A group of animals that look the same and
on its hind feet and spikes on its hands. A two-legged, plant-eating dinosaur, some of breed with one another to produce young.
which had crests on their heads.
invertebrAte steGosAur
An animal without a backbone. pAChyCephAlosAur A large, plant-eating dinosaur with rows
A two-legged, plant-eating dinosaur with of bony plates running down its back and
JurAssiC period a thick skull. spikes on its tail.
Period of geological time from 205 to 140 million
years ago. pAleontoloGist stromAtolites
A scientist who studies the forms of life that These structures were created in shallow,
lAurAsiA existed in former geological periods. warm water by sheets of blue-green algae and
The northern supercontinent made up of trapped sediments. Fossil stromatolites are
North America, Europe, and Asia. pAnGAeA evidence of early life.
The single land mass or supercontinent of the
limestone Permian Period. It began to break up during the superContinent
A sedimentary rock made from calcium Triassic Period. It means “All Earth.” An ancient landmass, such as Pangaea,
carbonate minerals. containing two or more continental plates.
plesiosAur
mAmmAl A swimming reptile with paddlelike limbs that synApsid
A warm-blooded animal with a backbone and lived in the world’s seas during the Jurassic and A mammal-like reptile whose skull has one
hair that gives birth to live young and feeds Cretaceous Periods. opening on either side.
them on milk.
predAtor tethys oCeAn
mAmmAl-like reptile An animal that kills other animals (prey) for food. A tropical ocean that separated Gondwana
Primitive reptile with some mammal-like and Laurasia. It was eventually closed by the
features, such as hair and teeth, that lived prey northward movement of Africa and India.
before the dinosaurs. Animals hunted and eaten by other animals.
theropod
mesozoiC prosAuropod A two-legged, meat-eating dinosaur armed
The middle era of life, from 251 to 65 million Early plant-eating dinosaur, which resembled with sharp teeth and claws.
years ago. Subdivided into the Triassic, the sauropods that replaced it.
Jurassic, and Cretaceous Periods. titAnosAur
pterosAur A very large, four-legged, plant-eating sauropod
mosAsAur A flying reptile with wings formed from skin. dinosaur.
A large marine reptile with long jaws and a
slender body. It was a ferocious predator. reptile triAssiC period
A cold-blooded animal with scales and a Period of geological time from 251 to 205
nodosAur backbone that lays its eggs on land. million years ago.
An armored dinosaur covered with bony
plates, spikes, and knobs. sAndstone tyrAnnosAur
Rock made up of mineral fragments deposited as A very large, two-legged, meat-eating dinosaur
order sediment and then compressed until hard. with short arms.
A group of related families. There are two
orders of dinosaurs—ornithischians sAurisChiAns vertebrAe
and saurischians. One of the two major orders of dinosaurs. The linked bones that make up the backbones
They had a reptilelike pelvis. This order includes of animals.
ornithisChiAns all theropods and sauropods.
One of the two major orders of dinosaurs. wArm-blooded
They had a birdlike pelvis. This order includes sAuropod When an animal, such as a mammal or a
horned dinosaurs, armored dinosaurs, and A bulky, long-necked, long-tailed, plant-eating bird, can control its own body temperature
stegosaurs. All were plant-eaters. dinosaur that walked on all four feet. and keep it at a constant level.

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