ornithischian a family of plant-eating dinosaurs with hip structures similar to birds, including tricer- atops, stegosaurus, ankylosaurs, and others. They are not, however, the ancestors of birds.
ornithopod from the Jurassic to the Cretaceous, any two- or four-legged plant eater without body armor.
oviraptor a theropod with a beaked, birdlike head and long fingers.
pachycephalosaurid a bipedal plant eater with an extraordinarily thick or bony head that lived in the Cretaceous period. Some, like pachycephalosaurus, had skulls 10 inches (25 cm) thick. Also known as a bonehead.
paleontologist a scientist who gathers fossils in the field and studies them to learn more about living organisms, such as dinosaurs, from past geological periods.
paleontology the study of living organisms and fossils from past geological periods.
parasaurolophus a beaked or duck-billed plant eater with a long crest that lived during the Cretaceous.
pterodactyl see pterosaur.
pterosaur closely related to the dinosaurs, a group of flying, fish-eating reptiles that lived from the Trias- sic to the end of the Jurassic period. Hollow-boned, with membranelike wings, they ranged in size from a few inches to as large as 40 feet (12 m). Pterodactyls are probably the best-known pterosaurs.
quetzalcoatlus a reptile closely related to the dinosaurs; a massive pterosaur with a 40-foot (12-m) wingspan that lived during the Cretaceous.
saurischian an order of dinosaurs that were the ancestors of birds, but with hip structures similar to lizards. Sauropods and theropods were both saurischians.
sauropod any large, four-legged plant eater with a long neck and tail, ranging in size from 7 feet (2 m) to more than 100 feet (30 m) long.
scute a bony or horny plate or scale, as found on the skin of crocodiles, which many dinosaurs may have had.
seismosaurus "quake lizard," a massive diplodocid dinosaur that grew as long as 170 feet (52 m) and lived during the late Jurassic. It had an extremely long neck, which it used to peer into and forage along the edges of thick woods, especially useful when the rest of its body was simply too big to pass through.
shantungosaurus the largest of all the duck-billed dinosaurs, or hadrosaurs, growing up to 48 feet (15 m) in length. It lived during the late Cretaceous.
Shiva located under the Arabian Sea off India, a massive crater, stretching 370 miles (600 km) across, 280 miles (450 km) wide, and 7.5 miles (12 km) deep, possibly created by an asteroid or meteoroid 65 million years ago, which may have, along with the impact at Chicxulub in the Yucatan, brought on the extinction of the dinosaurs. See Alvarez extinction theory, Chicxulub, multiple impact theory.
spinosaurid during the Cretaceous, a large meat eater characterized by a 6-foot (1.8-m) high sail on its back, thought to have been a heat regulator or possibly used for mating displays.
stegosauria during the Jurassic and into the Cretaceous, a group of ornithischian plant eaters characterized by a double row of armor plates running down their backs and ending in spikes at the end of the tails. Stegosaurus is the best-known example, also famous for its tiny head and walnut-sized brain.
strata layers of sediment or rock, often marking distinct geological periods (sing., stratum).
Tertiary period the geological period from 1.8 to 65 million years ago, following the extinction of the dinosaurs, within which mammals took center stage.
theropod any bipedal carnivore with hands and claws, ranging from the size of a chicken to 50 feet (15 m) tall, that lived from the Triassic to the end of the Cretaceous. Birds are believed to have evolved from theropods.
thyreophoran living from the Jurassic to the Cretaceous, any four-legged plant eaters with armored plates, including stegosaurs and ankylosaurs.
titanosaurid a group of very large, four-legged sauropods, characterized by long necks and tails, small heads, and armored backs that lived during the Cretaceous.
T. rex see TYRANNOSAURUS REX.
Triassic period the geological time period from 251 million to 199.6 million years ago, it marked the beginning of the reign of dinosaurs.
triceratops during the late Cretaceous, a four- legged plant eater that grew to be up to 29.5 feet (9 m) long, characterized by its three horns and neck frill.
Tyrannosaurus rex "tyrant lizard," a very large bipedal predator that grew as tall as 43 feet (13 m), had a 5-foot (1.5-m) long skull, and lived in North America during the Cretaceous.
velociraptor a small, swift-footed meat eater that had a slashing, sicklelike claw on each foot and lived during the Cretaceous period. According to the size of its brain case to body size ratio, it was likely among the most intelligent of the dinosaurs.
DOGS
alpha the dominant dog in a pack.
apple head a rounded or domed skull, as in the English toy spaniel.
apron the longer hairs found on the chest of many breeds.
badger-marked having a coat consisting of gray or black markings on white.
bat ear an erect ear that is rounded at the top, as in a bat.
bay a deep bark.
beard the tuft or long hairs under the chin.
belton a coat consisting of blue or orange and white hair.
bitch female dog.
blaze a white or light-colored streak running along the center of the head.
blond having a coat of light yellow or yellowish tan.
bloom the glossiness of the coat.
bobtail a tail cut short; also known as a docked tail.
brindle having a streaked or spotted coat.
brisket part of the chest between and slightly behind the forelegs.
brush a bushy tail.
bullbaiting the long-banned English sport of dogs tormenting bulls.
butterfly nose a nose with two or more different colors.
buttocks the rump.
button ear an ear that folds forward toward the eye, as in a fox terrier.
canine of the dog family, or like a dog.
chops the lower cheeks, especially in a bulldog.
cloddy thickset and low to the ground, as a Scottish terrier.
cobby short-bodied.
crest the ridge of the neck.
crop trimming the ears to make them pointed.
cynology the study of dogs and their history.
cynophobia fear of dogs.
dam mother.
dewclaw one of the short vestigial claws or digits, the remnant of a first toe, now useless.
dewlap the loose fold of skin hanging from the neck of many breeds, such as the bulldog and the bloodhound.
dingo wild dog of the Australian outback.
distemper an infectious disease of puppies and young dogs, caused by a virus.
docking the surgical removal or shortening of the tail.
eyeteeth the two projecting canine teeth in the upper jaw.
fawn having a pale, yellowish brown coat.
feather the fringe of hair along the tail and back of the legs.