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The following is a simplified classification of dinosaur families. A more detailed version can be found at List of dinosaur classifications.

Assemblage of Tetanuran theropods: Torvosaurus left above, Eustreptospondylus left below, Piatnitzkysaurus in cental position, Megalosaurus right below, Afrovenator right above, and Cryolophosaurus behind it

Several macronarian Sauropods, from left to right Camarasaurus, Brachiosaurus, Giraffatitan, and Euhelopus

Various ornithopod dinosaurs and one heterodontosaurid. Far left: Camptosaurus, left: Iguanodon, center background: Shantungosaurus, center foreground: Dryosaurus, right: Corythosaurus, far right (small): Heterodontosaurus, far right (large) Tenontosaurus.

• Dinosauria

• Saurischia (theropods and sauropods)

• Herrerasaurians (early bipedal predators)
• Theropods (all bipedal; most were carnivores)

• Coelophysoids (Coelophysis and close relatives)
• Ceratosaurians (Ceratosaurus and abelisaurids - the latter were important Late Cretaceous predators in southern continents)
• Spinosauroids (long bodies, short arms, some with crocodile-like skulls and bony "sails" in their backs)
• Carnosaurians (Allosaurus and close relatives, like Carcharodontosaurus)
• Coelurosaurians (diverse, with a range of body sizes and niches)

• Tyrannosauroids (small to gigantic, often with reduced forelimbs)
• Ornithomimosaurians ("ostrich-mimics", toothless, carnivores to herbivores)
• Therizinosauroids (bipedal herbivores with long arms and small heads)
• Oviraptorosaurians (toothless; their diet and lifestyle are uncertain)
• Dromaeosaurids (like the "raptors" in Jurassic Park)
• Troodontids (similar to dromaeosaurids, but more lightly built, and possibly omnivorous)
• Birds (the only living dinosaurs)

• Sauropodomorphs (quadrupedal herbivores with small heads and long necks and tails, and elephant-like bodies)

• "Prosauropods" (early relatives of sauropods; small to quite large; some possibly omnivorous; bipeds and quadrupeds)
• Sauropods (very large, usually over 15 meters long [49 ft])

• Diplodocoids (skulls and tails elongated; teeth typically narrow and pencil-like)
• Macronarians (boxy skulls; spoon-shaped or pencil-shaped teeth)

• Brachiosaurids (very long necks; forelimbs longer than hindlimbs)
• Titanosaurians (diverse; stocky, with wide hips; most common in the Late Cretaceous of southern continents)

• Ornithischians (diverse bipedal and quadrupedal herbivores)

• Heterodontosaurids (meter- or yard-scale herbivores or omnivores with prominent canine teeth)
• Thyreophorans (armored dinosaurs, mostly quadrupeds)

• Ankylosaurians (scutes as primary armor; some had club-like tails)
• Stegosaurians (spikes and plates as primary armor)

• Ornithopods (diverse, from meter- or yard-scale bipeds to 12 meter (39 ft) animals that could moves as both bipeds and quadrupeds, evolved a method of chewing using skull flexibility and large numbers of teeth)

• Hadrosaurids ("duckbilled dinosaurs")

• Pachycephalosaurians ("bone-heads", bipeds with domed or knobby growth on skulls)
• Ceratopsians (dinosaurs with horns and frills, although most early forms had only the beginnings of these features)

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