Dinosaurs, ACH-YIN

Dinosaur, the common name given to a group of reptiles, often very large, that first appeared roughly 245 million years ago (near the beginning of the Middle Triassic Epoch) and thrived worldwide for nearly 180 million years. Most died out by the end of the Cretaceous Period, about 66 million years ago, but many lines of evidence now show that one lineage evolved into birds about 150 million years ago.
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Achelousaurus
Achelousaurus, (Achelousaurus horneri), herbivorous ceratopsian dinosaur that lived between 83 million and 70 million......
Albertosaurus
Albertosaurus, (genus Albertosaurus), large carnivorous dinosaurs of the Late Cretaceous Period (99.6 million to......
Allosaurus
Allosaurus, (genus Allosaurus), large carnivorous dinosaurs that lived from 150 million to 144 million years ago......
Anatosaurus
Anatosaurus, (genus Anatosaurus), bipedal duck-billed dinosaurs (hadrosaurs) of the Late Cretaceous Period, commonly......
Ankylosaurus
Ankylosaurus, (genus Ankylosaurus), armoured ornithischian dinosaurs that lived 70 million to 66 million years......
Apatosaurus
Apatosaurus, (genus Apatosaurus), genus of at least two species of giant herbivorous sauropod dinosaurs that lived......
Archaeopteryx
Archaeopteryx, genus of feathered dinosaur that was once thought to be the oldest known fossil bird. The specimens......
brachiosaur
brachiosaur, (genus Brachiosaurus), any member or relative of the dinosaur genus Brachiosaurus, which lived 150......
brontosaurus
brontosaurus, (genus Brontosaurus), genus of large herbivorous sauropod dinosaurs living during the Late Jurassic......
Camarasaurus
Camarasaurus, (genus Camarasaurus), a group of dinosaurs that lived during the Late Jurassic Period (161 million......
Camptosaurus
Camptosaurus, (genus Camptosaurus), large herbivorous dinosaurs found as fossils in western Europe and western......
Carcharodontosaurus
Carcharodontosaurus, (genus Carcharodontosaurus), genus of massive predatory dinosaurs that inhabited North Africa......
carnosaur
carnosaur, any of the dinosaurs belonging to the taxonomic group Carnosauria, a subgroup of the bipedal, flesh-eating......
Caudipteryx
Caudipteryx, genus of small feathered theropod dinosaurs known from rock deposits of western Liaoning province,......
ceratopsian
ceratopsian, any of a group of plant-eating dinosaurs from the Cretaceous Period (146 million to 66 million years......
Ceratosaurus
Ceratosaurus, (genus Ceratosaurus), large carnivorous dinosaurs whose fossils date from the Late Jurassic Period......
Coelophysis
Coelophysis, (genus Coelophysis), small carnivorous dinosaurs found as fossils from the Late Triassic Period (228......
Compsognathus
Compsognathus, (genus Compsognathus), very small predaceous dinosaurs that lived in Europe during the Late Jurassic......
Confuciusornis
Confuciusornis, genus of extinct crow-sized birds that lived during the Late Jurassic and Early Cretaceous (roughly......
Deinonychus
Deinonychus, (genus Deinonychus), long-clawed carnivorous dinosaurs that flourished in western North America during......
Dilong
Dilong, (Dilong paradoxus), genus of small feathered theropod dinosaurs known from rock deposits of the Yixian......
Diplodocus
Diplodocus, (genus Diplodocus), gigantic dinosaurs found in North America as fossils from the Late Jurassic Period......
Dreadnoughtus
Dreadnoughtus, a genus of large sauropod dinosaurs, the largest land animal that ever lived. It had a total length......
dromaeosaur
dromaeosaur, (family Dromaeosauridae), any of a group of small to medium-sized carnivorous dinosaurs that flourished......
Euoplocephalus
Euoplocephalus, (genus Euoplocephalus), armoured North American dinosaur of the Late Cretaceous Period (99.6 million......
Europasaurus
Europasaurus, genus representing one of the smallest known sauropod dinosaurs, characterized by a distinctive arched......
feathered dinosaur
feathered dinosaur, any of a group of theropod (carnivorous) dinosaurs, including birds, that evolved feathers......
Giganotosaurus
Giganotosaurus, (Giganotosaurus carolinii), genus of a large theropod dinosaur in the family Carcharodontosauridae......
Herrerasaurus
Herrerasaurus, (genus Herrerasaurus), primitive carnivorous dinosaur or close relative of dinosaurs found as fossils......
Hypsilophodon
Hypsilophodon, (genus Hypsilophodon), small to medium-sized herbivorous dinosaurs that flourished about 115 million......
Iguanodon
Iguanodon, (genus Iguanodon), large herbivorous dinosaurs found as fossils from the Late Jurassic and Early Cretaceous......
Lambeosaurus
Lambeosaurus, (genus Lambeosaurus), duck-billed dinosaur (hadrosaur) notable for the hatchet-shaped hollow bony......
Maiasaura
Maiasaura, (genus Maiasaura), duck-billed dinosaurs (hadrosaurs) found as fossils from the Late Cretaceous Period......
Megalosaurus
Megalosaurus, (genus Megalosaurus), carnivorous dinosaur and the subject of the first scientific description of......
Nodosaurus
Nodosaurus, (genus Nodosaurus), armoured dinosaurs found as fossils in North America dating from 95 million to......
ornithischian
ornithischian, any member of the large taxonomic group of herbivorous dinosaurs comprising Triceratops and all......
Ornitholestes
Ornitholestes, (genus Ornitholestes), small, lightly built carnivorous dinosaur found as fossils from the Late......
Ornithomimus
Ornithomimus, (genus Ornithomimus), ostrichlike feathered dinosaurs found as fossils in Mongolian, European, and......
ornithopod
ornithopod, any member of the group of ornithischian dinosaurs characterized by a two-legged (bipedal) stance,......
Oviraptor
Oviraptor, (genus Oviraptor), small, lightly built predatory or omnivorous dinosaur that brooded its eggs in a......
Pachycephalosaurus
Pachycephalosaurus, genus of large and unusual dinosaurs found as fossils in deposits of North America dating to......
Pachyrhinosaurus
Pachyrhinosaurus, genus of horned ceratopsid dinosaurs that roamed northwestern North America from 71 million to......
Pentaceratops
Pentaceratops, (genus Pentaceratops), five-horned herbivorous dinosaur found as fossils in North America and possibly......
Plateosaurus
Plateosaurus, (genus Plateosaurus), dinosaurs known from extensive fossil material found in Europe dating to the......
Podokesaurus
Podokesaurus, (Podokesaurus holyokensis), small carnivorous North American dinosaur found as a single specimen......
Protoceratops
Protoceratops, (genus Protoceratops), ceratopsian dinosaur found as fossils in the Gobi Desert from 80-million-year-old......
Psittacosaurus
Psittacosaurus, (genus Psittacosaurus), primitive member of the horned dinosaurs (Ceratopsia) found as fossils......
saurischian
saurischian, any member of one of the two major lineages of dinosaurs, including birds and all dinosaurs more closely......
sauropod
sauropod, any member of the dinosaur subgroup Sauropoda, marked by large size, a long neck and tail, a four-legged......
Scutellosaurus
Scutellosaurus, genus of small ornithischian dinosaurs from the Early Jurassic Period (roughly 200 million to 176......
Spinosaurus
Spinosaurus, genus of theropod dinosaurs belonging to the family Spinosauridae, known from incomplete North African......
stegosaur
stegosaur, any of the plated dinosaur species, including Stegosaurus and Tuojiangosaurus of the Late Jurassic period......
Stegosaurus
Stegosaurus, (genus Stegosaurus), genus various plated dinosaurs (Stegosauria) of the Late Jurassic Period (159......
Struthiomimus
Struthiomimus, (genus Struthiomimus), ostrichlike dinosaurs found as fossils from the Late Cretaceous Period (99......
therizinosaur
therizinosaur, group of theropod dinosaurs that lived during the Late Cretaceous (roughly 100 million to 66 million......
theropod
theropod, any member of the dinosaur subgroup Theropoda, which includes all the flesh-eating dinosaurs. Theropods......
titanosaur
titanosaur, (clade Titanosauria), diverse group of sauropod dinosaurs classified in the clade Titanosauria, which......
Triceratops
Triceratops, (genus Triceratops), large quadrupedal plant-eating ceratopsian dinosaur that had a frill of bone......
tyrannosaur
tyrannosaur, any of a group of predatory dinosaurs that lived from the late Jurassic Period (about 150 million......
Tyrannosaurus rex
Tyrannosaurus rex, (Tyrannosaurus rex), species of predatory dinosaurs that lived during the end of the Cretaceous......
Velociraptor
Velociraptor, (genus Velociraptor), sickle-clawed dinosaur that flourished in central and eastern Asia during the......
Yinlong
Yinlong, ceratopsian dinosaur genus known from a single nearly complete skeleton taken from the Junggar Basin of......