Reptiles, ACH-EGY

Turtles, tuatara, lizards and snakes, and crocodiles make up the major groups of living reptiles today, and they collectively account for over 8,700 species. Plesiosaurs, pliosaurs, ichthyosaurs, and dinosaurs are part of the diverse group of now-extinct reptiles that were once found on Earth but that we are now unlikely to encounter.
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Reptiles Encyclopedia Articles By Title

Achelousaurus
Achelousaurus, (Achelousaurus horneri), herbivorous ceratopsian dinosaur that lived between 83 million and 70 million......
adder
adder, any of several groups of venomous snakes of the viper family, Viperidae, and the Australo-Papuan death adders,......
agama
agama, (genus Agama), any of about 30 species of lizards belonging to the family Agamidae (suborder Sauria). They......
Agamidae
Agamidae, (order Squamata), lizard family composed of about 350 species in about 50 genera. Agamids typically have......
Albertosaurus
Albertosaurus, (genus Albertosaurus), large carnivorous dinosaurs of the Late Cretaceous Period (99.6 million to......
alligator
alligator, (genus Alligator), either of two crocodilians related to the tropical American caimans (family Alligatoridae).......
alligator lizard
alligator lizard, any of 42 lizard species in the subfamily Gerrhonotinae of the family Anguidae in any of the......
alligator snapping turtle
alligator snapping turtle, (Macrochelys temminckii), species of freshwater turtle in the family Chelydridae. The......
Allosaurus
Allosaurus, (genus Allosaurus), large carnivorous dinosaurs that lived from 150 million to 144 million years ago......
American alligator
American alligator, (Alligator mississippiensis), species of alligator inhabiting freshwater rivers, lakes, and......
American crocodile
American crocodile, (Crocodylus acutus), moderately large species of crocodile inhabiting forests and freshwater......
amethystine python
amethystine python, (Simalia amethistina), long, slender, nonvenomous snake belonging to the family Pythonidae.......
anaconda
anaconda, (genus Eunectes), any of three to five species of large, constricting, water-loving snakes found in tropical......
Anatosaurus
Anatosaurus, (genus Anatosaurus), bipedal duck-billed dinosaurs (hadrosaurs) of the Late Cretaceous Period, commonly......
Aniliidae
Aniliidae, family of harmless burrowing snakes with primitive features such as a vestigial pelvic girdle, an external......
Ankylosaurus
Ankylosaurus, (genus Ankylosaurus), armoured ornithischian dinosaurs that lived 70 million to 66 million years......
anole
anole, (genus Anolis), any of more than 250 species of small tree-dwelling lizards related to iguanas (family Iguanidae).......
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......
Archelon
Archelon, extinct giant sea turtle known from fossilized remains found in North American rocks of the Late Cretaceous......
archosaur
archosaur, (subclass Archosauria), any of various reptiles, including all crocodiles and birds and all descendants......
Archosaurus
Archosaurus, early genus of reptiles found as fossils in Middle and Late Permian deposits of Europe (265 million......
armadillo lizard
armadillo lizard, (species Cordylus cataphractus), a southern African member of the family Cordylidae, known for......
arrau
arrau, large and somewhat flat freshwater turtle with a neck that does not retract but instead can be tucked to......
asp
asp, anglicized form of aspis, name used in classical antiquity for a venomous snake, probably the Egyptian cobra,......
bandy-bandy
bandy-bandy, (genus Vermicella), Australian snake of the cobra family Elapidae, strikingly ringed with black and......
Barbados threadsnake
Barbados threadsnake, (Leptotyphlops carlae), tiny burrowing member of the snake family Leptotyphlopidae. Reaching......
basilisk
basilisk, (genus Basiliscus), any of four species of forest lizards of tropical North and South America belonging......
Bauria
Bauria, extinct genus of mammal-like reptiles found as fossils in South African rocks of the Early Triassic Period......
Bitis
Bitis, snake genus belonging to the venomous viper family Viperidae, including the puff adders (e.g., Bitis arietans,......
black caiman
black caiman, (Melanosuchus niger), large caiman species best known as being the largest predator in the Amazon......
black mamba
black mamba, (Dendroaspis polylepis), species of mamba snake known for its large size, quickness, and extremely......
black snake
black snake, any of about a dozen species of snakes that are all black or nearly so. Australia has two species......
black-tailed rattlesnake
black-tailed rattlesnake, (Crotalus molossus), North American pit viper (subfamily Crotalinae, family Viperidae)......
Blanding’s turtle
Blanding’s turtle, (Emydoidea blandingii), freshwater turtle, family Emydidae, found in southern Canada and the......
blind snake
blind snake, (superfamily Typhlopoidea), any of several nonvenomous snakes characterized by degenerate eyes that......
boa
boa, common name for a variety of nonvenomous constricting snakes. There are more than 40 species of true boas......
boa constrictor
boa constrictor, (Boa constrictor), large thick-bodied snake of the boa family, Boidae. Its range is wide, from......
boomslang
boomslang, (Dispholidus typus), venomous snake of the family Colubridae, one of the few colubrid species that is......
box turtle
box turtle, any of two groups, Asian and North American, of terrestrial and semiaquatic turtles. Box turtles have......
brachiosaur
brachiosaur, (genus Brachiosaurus), any member or relative of the dinosaur genus Brachiosaurus, which lived 150......
Bradysaurus
Bradysaurus, (genus Bradysaurus), a group of extinct early reptiles found in South Africa as fossils in deposits......
brontosaurus
brontosaurus, (genus Brontosaurus), genus of large herbivorous sauropod dinosaurs living during the Late Jurassic......
brown snake
brown snake, any of several species of snakes named for their usual predominating colour. In New Guinea and Australia......
brown tree snake
brown tree snake, (Boiga irregularis), slender, mildly venomous, primarily arboreal snake of family Colubridae......
bull snake
bull snake, (Pituophis catenifer), North American constrictor snake of the family Colubridae known for its heavy-bodied......
Burmese python
Burmese python, (Python bivittatus), species of constrictor snake that is native to various environments in southern......
burrowing asp
burrowing asp, (genus Atractaspis), any of 19 species of venomous, secretive snakes, also known as mole vipers......
bushmaster
bushmaster, (genus Lachesis), the longest venomous snake in the New World, found in scrublands and forests from......
caiman
caiman, any of several species of Central and South American reptiles that are related to alligators and are usually......
caiman lizard
caiman lizard, any member of a genus (Dracaena) of lizards in the family Teiidae. These lizards (D. guianensis......
Calotes
Calotes, genus of arboreal (tree-dwelling) lizards of the family Agamidae, remarkable for their extreme colour......
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......
Captorhinus
Captorhinus, genus of extinct reptiles found as fossils in Permian rocks of North America (the Permian Period lasted......
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......
cat snake
cat snake, any of several groups of arboreal or semiarboreal rear-fanged snakes in the family Colubridae with eyes......
Caudipteryx
Caudipteryx, genus of small feathered theropod dinosaurs known from rock deposits of western Liaoning province,......
Cerastes
Cerastes, genus of venomous, desert-dwelling snakes of the viper family, Viperidae. There are two species, the......
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......
chameleon
chameleon, (family Chamaeleonidae), any of a group of primarily arboreal (tree-dwelling) Old World lizards best......
chicken turtle
chicken turtle, (Deirochelys reticularia), edible freshwater turtle (family Emydidae) found in the southeastern......
Chinese alligator
Chinese alligator, (Alligator sinensis), species of alligator inhabiting the stream, pond, and wetland ecosystems......
chuckwalla
chuckwalla, (genus Sauromalus), any of five species of stocky, slightly flattened lizards belonging to the subfamily......
Clemmys
Clemmys, genus of small, terrestrial or semi-aquatic turtles in the family Emydidae. The genus contains four species,......
Clidastes
Clidastes, (genus Clidastes), extinct ancient marine lizards belonging to a family of reptiles called mosasaurs.......
coachwhip
coachwhip, (Masticophis, sometimes Coluber, flagellum), nonvenomous snake of the family Colubridae that ranges......
cobra
cobra, any of various species of highly venomous snakes, most of which expand the neck ribs to form a hood. While......
Coelophysis
Coelophysis, (genus Coelophysis), small carnivorous dinosaurs found as fossils from the Late Triassic Period (228......
collared lizard
collared lizard, (genus Crotaphytus), any of nine species of lizards belonging to the lizard subfamily Crotaphytinae......
colubrid
colubrid, any member of the most common family of snakes, Colubridae, characterized by the complete absence of......
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......
copperhead
copperhead, any of several unrelated snakes named for their reddish head colour. The North American copperhead......
coral snake
coral snake, any of more than 100 species of small, secretive, and brightly patterned venomous snakes of the cobra......
Cordylidae
Cordylidae, family of small to medium-sized lizards that range in length from 6 to 30 cm (2.4 to 11.8 inches).......
crocodile
crocodile, (order Crocodylia, or Crocodilia), any of about 27 species of generally large, ponderous, amphibious......
crurotarsan
crurotarsan, (clade Crurotarsi), any member of clade Crurotarsi, the group of archosaurs, or “ruling reptiles,”......
Cuban crocodile
Cuban crocodile, (Crocodylus rhombifer), species of crocodile inhabiting freshwater swamps and streams of the Zapata......
Cuvier’s dwarf caiman
Cuvier’s dwarf caiman, (Paleosuchus palpebrosus), small caiman species known for being the most diminutive living......
cynodont
cynodont, (clade Cynodontia), any of a group of mammal-like reptiles of the order Therapsida that existed from......
Cynognathus
Cynognathus, genus of extinct advanced therapsids (mammals and their relatives) found as fossils in Lower Triassic......
Deinonychus
Deinonychus, (genus Deinonychus), long-clawed carnivorous dinosaurs that flourished in western North America during......
Diarthrognathus
Diarthrognathus, genus of extinct, advanced mammal-like reptiles found as fossils in Early Jurassic terrestrial......
Dilong
Dilong, (Dilong paradoxus), genus of small feathered theropod dinosaurs known from rock deposits of the Yixian......
Dimetrodon
Dimetrodon, (genus Dimetrodon), extinct relative of primitive mammals that is characterized by a large, upright,......
Dimorphodon
Dimorphodon, (genus Dimorphodon), primitive flying reptiles found as fossils in European deposits from the Early......
dinosauromorph
dinosauromorph, any of a group of archosaurian reptiles that includes dinosaurs and all other reptiles bearing......
Diplodocus
Diplodocus, (genus Diplodocus), gigantic dinosaurs found in North America as fossils from the Late Jurassic Period......
Draco
Draco, genus of the lizard family Agamidae. Members of the genus are commonly referred to as flying lizards, because......
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......
dwarf crocodile
dwarf crocodile, (Osteolaemus tetraspis), the world’s smallest living crocodile species, growing to a maximum length......
eastern diamondback rattlesnake
eastern diamondback rattlesnake, (Crotalus adamanteus), large venomous pit viper (subfamily Crotalinae, family......
Edaphosaurus
Edaphosaurus, (genus Edaphosaurus), primitive herbivorous relative of mammals that is found in fossil deposits......
egg-eating snake
egg-eating snake, any of the five species of the genus Dasypeltis of sub-Saharan Africa and Elachistodon westermanni......
Egyptian cobra
Egyptian cobra, (Naja haje), large, extremely venomous snake of the cobra family (Elapidae), widespread in semiarid......

Reptiles Encyclopedia Articles By Title