ZoomDinosaurs.com DINOSAUR ANATOMY AND BEHAVIOR

Dinosaurs ranged in size from the size of a chicken to well over 100 feet long. Most dinosaurs were somewhere in the middle. The modern-day blue whale is the largest animal that ever lived - it is larger than any dinosaur was.

No one knows why some of the dinosaurs (and some other Mesozoic Era reptiles) got so huge and none do today. This is one of the most interesting unanswered questions in paleontology. There are a lot of theories, but some of them are pretty bizarre; none are generally accepted

LONGEST
The longest dinosaurs were sauropods; they were gigantic, slow-moving, tiny-headed, cow-like plant-eaters from the late Jurassic and the Cretaceous period. They had very long necks which were useful for reaching wide (and tall) swatches of vegetation. The lengthy neck was counterbalanced by a massive tail. These sauropods are the largest land animals ever discovered:

Supersaurus - 134 feet long (41 m) Argentinosaurus - 115-130 feet long (35-40 m); 80-100 metric tons Seismosaurus ("Earth-shaking lizard") - 120+ feet long (37 m); +80 tons Ultrasauros - 100+ feet long (30 m), +80 tons Diplodocus - grew up to 90 feet long (28 m). Brachiosaurus - about 85 feet long (26 m), 40 feet tall, and weighed 70-80 tons.

---

The biggest carnivores were theropods from the Cretaceous period:

Giganotosaurus carolinii - found in Patagonia, Argentina. 47 feet long (14 m), 8 tons in weight, and 12 feet tall (4 m). Tyrannosaurus rex - found in North America - 40-50 feet long (12-15 m), 6 tons in weight. Carcharodontosaurus saharicus - (meaning shark-toothed lizard) found in in Morocco, Africa, by Paul Sereno. It was probably about 45 feet long and had 5 inch long teeth. Its skull (5 feet 4 inches) is larger than T. rex's, but it had a tiny brain cavity (half the size of T. rex's).

---

TALLEST
The tallest dinosaurs were brachiosaurid sauropods; they had front legs that were longer than their back legs and had a giraffe-like stance. They were gigantic, slow moving, tiny-headed, cow-like plant-eaters from the late Jurassic and the Cretaceous period. They had very long necks which were held upright and were useful for reaching wide (and tall) swatches of vegetation. The lengthy neck was counterbalanced by a massive tail. These sauropods are among the largest land animals ever discovered:

Sauroposeidon, a newly-found brachiosaurid from Oklahoma, +60 tons, 60 feet tall. Ultrasauros - 100+ feet long (30 m), +80 tons, +40 ft tall Brachiosaurus - about 85 feet long (26 m), 40 feet tall, and weighed 70-80 tons.

---

SMALLEST
Small fossils are found less easily than large fossils. Also, when small animals die, they are likely to be eaten, perhaps whole, by larger animals. The smallest dinosaurs yet discovered are:

Compsognathus, a theropod (meat-eater) 2 feet (60 cm) long, from 145 million years ago. It was the size of a chicken and weighed about 6.5 pounds (3 kg). Saltopus - a 2 feet (60 cm) long insectivore (insect-eater) from about 200 million years ago. Lesothosaurus - a 3 feet (90 cm) long, fast running, plant-eater from Africa, 200 million years ago.

DINOSAUR SIZE ACTIVITIES

• Dinosaur size printout
• Dinosaur Graphing! Graph the sizes of the dinosaurs. For second and third graders.

---

SIZES OF THE MAJOR GROUPS OF DINOSAURS

ORDER	SUBORDER	INFRA- ORDER	DINOSAUR FAMILY	SOME GENERA	TIME RANGE	SIZE RANGE
S A U R I S C H I A N S S A U R I S C H I A N S S A U R I S C H I A N S	THEROPODS Bipedal predators THEROPODS Bipedal predators THEROPODS Bipedal predators	Herrerasauria	Saltopodidae (leaping feet)	Saltopus, Eoraptor	late Triassic	2-3 feet (0.7-1 m) long
			Staurikosaurids (Southern Cross lizards)	Staurikosaurus	late Triassic	6.5-10 feet (2-3 m) long
			Herrerasaurids (Herrera lizards)	Herrerasaurus	late Triassic to early Jurassic	7-10 feet (2-3 m) long or more
		Ceratosauria	Coelophysids (hollow form)	Coelophysis, Saltopus	late Triassic to early Jurassic	2-10 feet (0.6-3 m) long
			Ceratosaurids (horned lizards)	CeratosaurusSyntarsus	Early-Late Cretaceous	11.5-20 feet (3.5-6 m) long
			Podokesaurids (swift-footed lizards)	Podokesaurus, Syntarsus	Early-Late Jurassic	3-10 feet (1-3 m) long
			Abelisaurids (Abel's lizard)	Abelisaurus, Indosaurus	Early-Late Cretaceous	up to 36 feet (11 m) long
			Noasaurids (lizards from NW Argentina)	Noasaurus	Late Cretaceous	8 feet (2.4 m) long
			Segisauridae (Segi Canyon Arizona lizards)	Segisaurus, Dilophosaurus	late Triassic to Early Jurassic	20 feet (6 m) long
		Coelurosauria	Coelurids (hollow tails)	Coelurus, Ornitholestes	Late Jurassic to Late Cretaceous	4-8 feet (1.2-2.4 m) long
			Dryptosaurids (wounding lizards)	Dryptosaurus	Late Cretaceous	+20 feet (6 m) long
			Compsognathids (pretty jaw)	Compsognathus	late Jurassic to early Cretaceous	2-3 feet (0.6-0.9 m) long
			Oviraptors (egg thieves)	Oviraptor	Late Cretaceous	6 feet (1.8 m) long
			Caenagnathids (recent jawless)	Caenagnathus, Microvenator	Late Jurassic to Late Cretaceous	7 feet (2 m) long
			Avimimids (bird mimics)	Avimimus	Late Cretaceous	5 feet (1.5 m) long
			Ornithomimids (bird mimics)	Ornithomimus	Late Jurassic to Late Cretaceous	11.5-19.5 feet (3.5-6 m) long
			Garudimimids (Garuda mimics)	Garudimimus, Harpymimus	Mid-Late Cretaceous	11.6 feet (3.5 m) long
			Deinocherids (terrible hands)	Deinocheirus	Late Cretaceous	45 feet (13.5 m) long (unsure - from incomplete fossils)
			Dromaeosaurids (running lizards)	Caudipteryx, Deinonychus, Dromaeosaurus, Protarchaeopteryx, Sinornithosaurus, Sinosauropteryx, Unenlagia, Utahraptor, Velociraptor	Mid-Jurassic to Late Cretaceous	6-13 feet (1.8-4 m) long
			Troödontids (wounding teeth)	Troödon	Late Cretaceous	6.6 feet (2 m) long
			Tyrannosaurids (tyrant lizards)	Tyrannosaurus, Albertosaurus, Nanotyrannus	Late Cretaceous	16-40 feet (5-12 m) long
		Carnosauria	Allosaurids (different lizards)	Allosaurus, Yangchuanosaurus	Late Jurassic	33-42 feet (10-12.8 m) long
			Carcharodontosaurids (horned lizards)	Carcharodontosaurus, Giganotosaurus	Mid - Late Cretaceous	40+ feet (12 m) long
			Spinosaurids (thorn lizards)	Spinosaurus, Suchomimus	Late Jurassic to Late Cretaceous	50 feet (15 m) long
			Baryonychids (heavy claws)	Baryonyx	Early Cretaceous	30 feet (9 m) long
			Megalosaurids (giant lizards)	Megalosaurus, Altispinax, Erectopus	Late Jurassic to Late Cretaceous	23-30 feet (7-9 m) long
		Segnosauria	Therizinosaurids (scythe lizards)	Therizinosaurus	Late Cretaceous	35 feet (10.7 m) long
			Segnosaurids (slow lizards)	Segnosaurus	Late Cretaceous	16-30 feet (5-9 m) long
	SAUROPODS Quadrupedal herbivores	Prosauropoda	Anchisaurids (near lizards)	Anchisaurus	Mid-Triassic- Early Jurassic	7-10 feet (2-3 m) long
			Plateosaurids (flat lizards)	Plateosaurus, Mussaurus	late Triassic - Early Jurassic	5-26 feet (1.5-8 m) long
			Melanorosaurids (black mountain lizard)	Melanorosaurus, Riojasaurus	late Triassic- Early Jurassic	19-40 feet (6-12 m) long
			Massospondylidae (black mountain lizard)	Massospondylus	late Triassic to Early Jurassic	13 feet (4 m) long
		Sauropoda	Cetiosaurids (whale lizards)	Cetiosaurus, Protognathus	Late Jurassic to Late Cretaceous	.
			Camarasaurids (chambered lizards)	Camarasaurus	Late Jurassic to Late Cretaceous	40-60 feet (12-18 m) long
			Dicraeosaurids (two-forked lizards)	Amargasaurus, Dicraeosaurus, Rebbachisaurus	Late Jurassic-Early Cretaceous	33-28 feet (10-20 m) long
			Euhelopodids (good marsh feet)	Euhelopus, Tienshanosaurus	Late Jurassic	33-90 feet (10-27 m) long
			Titanosaurids (titanic lizards)	Aegyptosaurus, Alamosaurus, Andesaurus, Argentinosaurus, Hypselosaurus, Quaesitosaurus, Saltasaurus, Titanosaurus	Late Jurassic to Late Cretaceous	30-70 feet (9-21 m) long
			Diplodocids (double-beamed form)	Diplodocus, Apatosaurus, Barosaurus, Supersaurus, Seismosaurus	Late Jurassic to Late Cretaceous	54-90 feet (16.5-27 m) long
			Brachiosaurids (arm lizards)	Astrodon, Brachiosaurus, Ultrasauros	Mid-Late Jurassic- Early Cretaceous	33-82 feet (10-25 m) long
O R N I T H I S C H I A N S O R N I T H I S C H I A N S	ORNITH- OPODS herbivores	Fabrosauria, Lesotho- sauria	Fabrosaurids (Fabre's lizards)	Fabrosaurus, Lesothosaurus, Xiaosaurus	late Triassic to Early Jurassic	3.3 feet (1 m) long
			Heterodontosaurids (different-teeth lizards)	Heterodontosaurus	late Triassic to Early Jurassic	4 feet (1.2 m) long
		Ornithopoda	Hypsilophodontids (high-ridged teeth)	Hypsilophodon, Orodromeus	Mid-Jurassic to Late Cretaceous	3-8 feet (0.9-2.4 m) long
			Dryosaurids (oak lizards)	Dryosaurus	Mid-Jurassic to Early Cretaceous	9-21 feet (2.7-6.5 m) long
			Iguanodontids (iguana teeth)	Iguanodon, Ouranosaurus, Anoplosaurus	Early- Late Cretaceous	13.5-29 feet (4-9 m) long
			Camptosaurids (bent lizards)	Camptosaurus, Muttaburrasaurus	Mid-Jurassic to Late Cretaceous	4-23 feet (1.2-7 m) long
			Hadrosaurids (big lizards)	Hadrosaurus, Maiasaura, Anatotitan, Edmontosaurus, Saurolophus, Trachodon	Late Cretaceous	12-50 feet (3.7-15 m) long
			Lambeosaurids (Lambe's lizard)	Lambeosaurus, Bactrosaurus, Corythosaurus, Jaxartosaurus, Parasaurolophus	Late Cretaceous	13-50 feet (4-15 m) long
			Thescelosaurids (wonderful lizards)	Thescelosaurus	Late Cretaceous	11 feet (3.4 m) long
	MARGINO- CEPHALIA herbivores	Pachycephalo- sauria	Pachycephalosaurids (thick-headed lizards)	Pachycephalosaurus, Stegoceras, Stygimoloch	Early - Late Cretaceous	3-15 feet (0.9-4.6 m) long
			Homalocephalids (even-headed forms)	Wannanosaurus	Late Cretaceous	1.5-10 feet (0.5-3 m) long
		Ceratopsia	Protoceratopsids (first horned faces)	Protoceratops, Bagaceratops, Leptoceratops, Montanoceratops, Notoceratops, Zuniceratops	Late Cretaceous	3.3-10 feet (1-3 m) long
			Ceratopsidae (horned faces)	Anchiceratops, Avaceratops, Arrhinoceratops, Brachyceratops, Ceratops, Monoclonius, Styracosaurus, Torosaurus, Triceratops	Late Cretaceous	6-30 feet (1.8-9 m) long
			Psittacosaurids (parrot lizards)	Psittacosaurus	Early Cretaceous	6.5 feet (2 m) long
	THYREO- PHORA (ENOPLA- SAURIA) armored, herbivorous, quadrupeds	x	Scutellosaurids (small-shield lizard)	Scutellosaurus	Early Jurassic to Late Jurassic	2.4 feet (0.6-1.2 m) long
			Scelidosaurids (limb lizards)	Scelidosaurus	Early Jurassic	13 feet (4 m) long
		Stegosauria	Huayangosaurids (Huayang lizards)	Huayangosaurus, Tatisaurus	Mid-Jurassic	13 feet (4 m) long
			Stegosaurinae (roof lizards)	Stegosaurus, Dacentrurus, Kentrosaurus, Tuojiangosaurus, Yingshanosaurus	Late Cretaceous	13-30 feet (3-9 m) long
			Stegosauridae (roof lizards)	Craterosaurus, Regnosaurus	Early Cretaceous	13 feet (4 m) long
		Ankylosauria	Nodosaurids (node lizards)	Nodosaurus, Acanthopholis, Brachyspondosaurus, Edmontonia, Hoplitosaurus, Minmi, Hylaeosaurus, Polacanthus, Sauropelta, Struthiosaurus	Mid-Jurassic - Late Cretaceous	6-25 feet (1.8-7.6 m) long
			Ankylosaurids (fused lizards)	Ankylosaurus, Euoplocephalus, Tarchia, Talarurus	Early - Late Cretaceous	18-35 feet (5.5-10.7 m) long

ZoomDinosaurs.com DINOSAUR ANATOMY AND BEHAVIOR

Enchanted Learning^®
Over 35,000 Web Pages
Sample Pages for Prospective Subscribers, or click below

Click to read our Privacy Policy

E-mail