The Dinosauria superorder was divided into the two orders Ornithischia and Saurischia by Harry Seeley in 1887. The division is based on the bird-like form of the pelvis, the possession of a predentary, details in the vertebrae and armor, and has been generally adopted. The predentary is an extra bone in the front of the lower jaw, and extends the dentary (the main lower jaw bone). The predentary coincides with the premaxilla in the upper jaw. Together they form a beak ...

See also:

Ornithischia, Ornithischia - Characteristics, Ornithischia - Classification, Ornithischia - Taxonomy

Read more here: » Ornithischia: Encyclopedia II - Ornithischia - Characteristics

The Dinosauria superorder was divided into the two orders Ornithischia and Saurischia by Harry Seeley in 1887. The division is based on the bird-like form of the pelvis, the possession of a predentary, details in the vertebrae and armor, and has been generally adopted. The predentary is an extra bone in the front of the lower jaw, and extends the dentary (the main lower jaw bone). The predentary coincides with the premaxilla in the upper jaw. Together they form a beak ...

See also:

Ornithischia, Ornithischia - Characteristics, Ornithischia - Systematics

Read more here: » Ornithischia: Encyclopedia II - Ornithischia - Characteristics

 Testudines - Turtles  Rhynchocephalia - Tuataras  Squamata   Suborder Sauria- Lizards   Suborder Serpentes - Snakes   Suborder Amphisbaenia - Worm lizards  Crocodilia - Crocodilians  Pterosauria - Flying reptiles Superorder Dinosauria  Saurischia  Ornithischia Reptiles are tetrapods, and also are amniotes, animals whose embryos are surrounded by an amniotic membrane. Today they are represented by four surviving ...

Including:

• Reptile - Classification of reptiles
• Reptile - Evolution of the reptiles
• Reptile - Systems
• Reptile - Circulatory
• Reptile - Respiratory
• Reptile - Excretion
• Reptile - Nervous
• Reptile - Sexual

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Dinosaurs are vertebrate animals that range from reptile-like to bird-like.[1] Dinosaurs dominated the terrestrial ecosystem for over 160 million years, first appearing around 230 million years ago. 65 million years ago, at the end of the Cretaceous period, all non-avian dinosaurs became extinct. Dinosaurs still exist today in the line of birds (avian dinosaurs). Knowledge about dinosaurs is derived from both fossil and non-fossil records, includ ...

Including:

• Dinosaur - What is a dinosaur?
• Dinosaur - Definition
• Dinosaur - Size
• Dinosaur - Behavior
• Dinosaur - Study of dinosaurs
• Dinosaur - Classification
• Dinosaur - Order Saurischia
• Dinosaur - †Order Ornithischia
• Dinosaur - Evolution
• Dinosaur - Areas of debate
• Dinosaur - Warm-blooded?
• Dinosaur - Feathered dinosaurs and the bird connection
• Dinosaur - Evidence for Cenozoic dinosaurs
• Dinosaur - Bringing dinosaurs back to life
• Dinosaur - Discovery of probable soft tissue from dinosaur fossils
• Dinosaur - Extinction theories
• Dinosaur - Asteroid collision
• Dinosaur - The Oort cloud
• Dinosaur - Environment changes
• Dinosaur - History of discovery
• Dinosaur - In popular culture
• Dinosaur - Notes

Read more here: » Dinosaur: Encyclopedia - Dinosaur

Unless otherwise specified, the follow is a list of dinosaurs for which almost complete skeletons have been found on the island. There are also many more species known only from a single or very few bones. Dinosaurs of the Isle of Wight - Order Ornithischia. Suborder Ornithopoda ("bird-footed", bipedal herbivores) Iguanodon bernissartensis: Vertebrae of the two Iguanadon species are particularly common. Iguanodon atherfieldensis Valdosaurus canalicul ...

See also:

Dinosaurs of the Isle of Wight, Dinosaurs of the Isle of Wight - Geological strata, Dinosaurs of the Isle of Wight - The Cretaceous habitat, Dinosaurs of the Isle of Wight - List of dinosaur species, Dinosaurs of the Isle of Wight - Order Ornithischia, Dinosaurs of the Isle of Wight - Order Saurischia, Dinosaurs of the Isle of Wight - Other meanings

Read more here: » Dinosaurs of the Isle of Wight: Encyclopedia II - Dinosaurs of the Isle of Wight - List of dinosaur species

Sauropodomorphs were adapted to browsing high among the trees, and most of their defining characteristics support this feeding strategy. A light, tiny skull on the end of a long neck (with ten or more elongated cervical vertebrae) was balanced by a long tail (with one to three extra sacral vertebrae) when reaching high above the ground. Their teeth were weak, and shaped like leaves or spoons (lanceolate or spatulate). Their jaws became like scissors in the sauropods, for chopping off vegetation. Instead of grinding teeth, they had sto ...

See also:

Sauropodomorpha, Sauropodomorpha - Description, Sauropodomorpha - Range, Sauropodomorpha - Classification

Read more here: » Sauropodomorpha: Encyclopedia II - Sauropodomorpha - Description

Among the ankylosaurids, Euoplocephalus, was exceeded in size by only Tarchia and Ankylosaurus. Euoplocephalus was 6 meters long, and weighed about 2 metric tonnes (2.2 tons). While it was 2.4 meters (8 feet) wide, it was low-slung, with short, stout legs. The rear legs were larger than the front legs, and all four limbs were tipped with hoof-like claws. A trackway of an ankylosaur found in 1996 at Sucre, Bolivia indicates that Euoploce ...

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Euoplocephalus, Euoplocephalus - Description, Euoplocephalus - Armed and armored, Euoplocephalus - Environment, Euoplocephalus - Classification and history, Euoplocephalus - Etymology, Euoplocephalus - Cladogram

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Dinosaur - Definition. The superorder or clade "Dinosauria" was formally named by the English scientist Richard Owen in 1842. The term is a portmanteau derived from the Greek words deinos ("terrible" or "fearfully great" or "formidable") and sauros ("lizard" or "reptile"). Owen chose it to express his awe at the size and majesty of the extinct animals, not out of fear or trepidation at their size ...

See also:

Dinosaur, Dinosaur - What is a dinosaur?, Dinosaur - Definition, Dinosaur - Size, Dinosaur - Behavior, Dinosaur - Study of dinosaurs, Dinosaur - Classification, Dinosaur - Order Saurischia, Dinosaur - †Order Ornithischia, Dinosaur - Evolution, Dinosaur - Areas of debate, Dinosaur - Warm-blooded?, Dinosaur - Feathered dinosaurs and the bird connection, Dinosaur - Evidence for Cenozoic dinosaurs, Dinosaur - Bringing dinosaurs back to life, Dinosaur - Discovery of probable soft tissue from dinosaur fossils, Dinosaur - Extinction theories, Dinosaur - Asteroid collision, Dinosaur - The Oort cloud, Dinosaur - Environment changes, Dinosaur - History of discovery, Dinosaur - In popular culture, Dinosaur - Religious points of view, Dinosaur - Notes and references, Dinosaur - General references

Read more here: » Dinosaur: Encyclopedia II - Dinosaur - What is a dinosaur?

Dinosaurs are divided into two major orders, the Saurischia and the Ornithischia, on the basis of hip structure. Cladograms and phylogenetic definitions in this scheme are based primarily on those in The Dinosauria, Second Edition (ed. Weishampel, Dodson & Osmolska, 2004). The symbol + between taxa should be read as indicating a node-based clade defined as comprising all decendants of the last common ancestor of the "added" taxa; the symbol > ("greater than") should be read as indicating a stem-based taxon comprising all organisms shari ...

See also:

Dinosaur classification, Dinosaur classification - Another scheme

Read more here: » Dinosaur classification: Encyclopedia II - Dinosaur classification - Another scheme

Reptile - Circulatory. Most reptiles have closed circulation via a three-chamber heart consisting of two atria and one, variably-partitioned ventricle. There is usually one pair of aortic arches. In spite of this, due to the fluid dynamics of blood flow through the heart, there is little mixing of oxygenated and deoxygenated blood in the three-chamber heart. Furthermore, the blood flow can be altered to shunt either deoxygenated blood to the body or oxygenated blood to the lungs, which gives the animal greater co ...

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Reptile, Reptile - Classification of reptiles, Reptile - Evolution of the reptiles, Reptile - Systems, Reptile - Circulatory, Reptile - Respiratory, Reptile - Excretion, Reptile - Nervous, Reptile - Sexual

Read more here: » Reptile: Encyclopedia II - Reptile - Systems

The terms Sauropsida ("Lizard Faces") and Theropsida ("Beast Faces") were coined in 1916 by E.S. Goodrich to distinguish between lizards, birds, and their relatives on one hand (Sauropsida) and mammal-like reptiles and mammals (Theropsida) on the other. This division is supported by the nature of the hearts and blood-vessels in each group, and other features such as the structure of the forebrain. According to Goodrich both lineages evolved from an earlier stem group, the Protosauria ("First Lizards") which i ...

See also:

Sauropsid, Sauropsid - History of the Term Sauropsida, Sauropsid - Sauropsida versus Reptilia, Sauropsid - Taxonomy

Read more here: » Sauropsid: Encyclopedia II - Sauropsid - History of the Term Sauropsida

Sauropodomorphs were adapted to browsing high among the trees, and most of their defining characteristics support this feeding strategy. A light, tiny skull on the end of a long neck (with ten or more elongated cervical vertebrae) was balanced by a long tail (with one to three extra sacral vertebrae) when reaching high above the ground. Their teeth were weak, and shaped like leaves or spoons (lanceolate or spatulate). Their jaws became like scissors in the sauropods, for chopping off vegetation. Instead of grinding teeth, they had sto ...

See also:

Sauropodomorpha, Sauropodomorpha - Description, Sauropodomorpha - Range, Sauropodomorpha - Classification, Sauropodomorpha - Taxonomy

Read more here: » Sauropodomorpha: Encyclopedia II - Sauropodomorpha - Description

Euoplocephalus lived between 65 and 70 million years ago, in the Campanian and Maastrichian ages of the late Cretaceous period. Euoplocephalus was plant eating (herbivorous) dinosaur. It had a complicated nose design (nasal structure), which indicates that it probably had a good sense of smell, and flexible legs which it might have used for digging. The stiff, low-slung dinosaur had poor teeth (weak dentition), so it must have grazed on fl ...

See also:

Euoplocephalus, Euoplocephalus - Description, Euoplocephalus - Armed and armored, Euoplocephalus - Environment, Euoplocephalus - Classification and history, Euoplocephalus - Etymology, Euoplocephalus - Cladogram

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Among the very first dinosaurs to evolve in the late Triassic, about 230 million years ago (Mya), they became the dominant herbivores by the early Jurassic. Their decline in the early Cretaceous corresponded with the spread of flowering plants (angiosperms) and advanced ornithischians, another major group of herbivorous dinosaurs noted for their highly developed chewing mechanisms. Like all non-avian dinosaurs, the sauropodomorphs became extinct 65 Mya during ...

See also:

Sauropodomorpha, Sauropodomorpha - Description, Sauropodomorpha - Range, Sauropodomorpha - Classification, Sauropodomorpha - Taxonomy

Read more here: » Sauropodomorpha: Encyclopedia II - Sauropodomorpha - Range

The Island's dinosaurs come from the Wessex formation, which dates from between 125 and 110 million years go. During this time the Isle of Wight, then located on a latitude at which North Africa resides today, had a subtropical environment, and was part of a large river valley complex, which ran along the south coast of England to Belgium. A world of ponds, rivers and swamps, and so had conditions favourable for the formation of fossils. Animal remains from this time include crocodiles, turtles, pterosaurs, mam ...

See also:

Dinosaurs of the Isle of Wight, Dinosaurs of the Isle of Wight - Geological strata, Dinosaurs of the Isle of Wight - The Cretaceous habitat, Dinosaurs of the Isle of Wight - List of dinosaur species, Dinosaurs of the Isle of Wight - Order Ornithischia, Dinosaurs of the Isle of Wight - Order Saurischia, Dinosaurs of the Isle of Wight - Other meanings

Read more here: » Dinosaurs of the Isle of Wight: Encyclopedia II - Dinosaurs of the Isle of Wight - The Cretaceous habitat

Among the very first dinosaurs to evolve in the late Triassic, about 230 million years ago (Mya), they became the dominant herbivores by the early Jurassic. Their decline in the early Cretaceous corresponded with the spread of flowering plants (angiosperms) and advanced ornithischians, another major group of herbivorous dinosaurs noted for their highly developed chewing mechanisms. Like all non-avian dinosaurs, the sauropodomorphs became extinct 65 Mya during ...

See also:

Sauropodomorpha, Sauropodomorpha - Description, Sauropodomorpha - Range, Sauropodomorpha - Classification

Read more here: » Sauropodomorpha: Encyclopedia II - Sauropodomorpha - Range

The sudden mass extinction of the non-avian dinosaurs, which occurred around 65 million years ago, is one of the most intriguing mysteries in paleontology. Many other groups of animals also became extinct at this time, including ammonites (nautilus-like mollusks), mosasaurs, plesiosaurs, pterosaurs, herbivorous turtles and crocodiles, most birds, and many groups of mammals.[32] The nature of the event which caused this mass extinction has been extensively studied since the 1970s. At present, several related th ...

See also:

Dinosaur, Dinosaur - What is a dinosaur?, Dinosaur - Definition, Dinosaur - Size, Dinosaur - Behavior, Dinosaur - Study of dinosaurs, Dinosaur - Classification, Dinosaur - Order Saurischia, Dinosaur - †Order Ornithischia, Dinosaur - Evolution, Dinosaur - Areas of debate, Dinosaur - Warm-blooded?, Dinosaur - Feathered dinosaurs and the bird connection, Dinosaur - Evidence for Cenozoic dinosaurs, Dinosaur - Bringing dinosaurs back to life, Dinosaur - Discovery of probable soft tissue from dinosaur fossils, Dinosaur - Extinction theories, Dinosaur - Asteroid collision, Dinosaur - The Oort cloud, Dinosaur - Environment changes, Dinosaur - History of discovery, Dinosaur - In popular culture, Dinosaur - Religious points of view, Dinosaur - Notes and references, Dinosaur - General references

Read more here: » Dinosaur: Encyclopedia II - Dinosaur - Extinction theories

Several thousand fossil species showing a clear smooth transition from the ancestors of reptiles to present-day reptiles exist. Hylonomus is the oldest-known reptile, and was about 8 to 12 inches (20 to 30 cm) long. Westlothiana has been suggested as the oldest reptile, but is for the moment considered to be more related to amphibians than amniotes. Petrolacosaurus, Araeoscelis, Paleothyris, Hylonomus, Ophiacodontidae, Archaeothyris, mesosaurs and Ophiacodon are other examples. The first true "reptile" or Amniotes are categorized as A ...

See also:

Reptile, Reptile - Classification of reptiles, Reptile - Evolution of the reptiles, Reptile - Systems, Reptile - Circulatory, Reptile - Respiratory, Reptile - Excretion, Reptile - Nervous, Reptile - Sexual

Read more here: » Reptile: Encyclopedia II - Reptile - Evolution of the reptiles

From the classical standpoint, reptiles included all the amniotes except birds and mammals. Thus reptiles were defined as the set of animals that includes crocodiles, alligators, tuatara, lizards, snakes, amphisbaenians and turtles, grouped together as the class Reptilia (Latin repere, "to creep"). This is still the usual definition of the term. However, in recent years, many taxonomists have begun to insist that taxa should be monophyletic, that is, groups should include all descendants of a particular form. The reptile ...

See also:

Reptile, Reptile - Classification of reptiles, Reptile - Evolution of the reptiles, Reptile - Systems, Reptile - Circulatory, Reptile - Respiratory, Reptile - Excretion, Reptile - Nervous, Reptile - Sexual

Read more here: » Reptile: Encyclopedia II - Reptile - Classification of reptiles

Dinosaur fossils have been known of for millennia, although their true nature was not recognized; the Chinese considered them to be dragon bones, while Europeans believed them to be the remains of giants and other creatures killed by the Great Flood. The first dinosaur species to be identified and named was Iguanodon, which was discovered in 1822 by the English geologist Gideon Mantell, who recognized similarities bet ...

See also:

Dinosaur, Dinosaur - What is a dinosaur?, Dinosaur - Definition, Dinosaur - Size, Dinosaur - Behavior, Dinosaur - Study of dinosaurs, Dinosaur - Classification, Dinosaur - Order Saurischia, Dinosaur - †Order Ornithischia, Dinosaur - Evolution, Dinosaur - Areas of debate, Dinosaur - Warm-blooded?, Dinosaur - Feathered dinosaurs and the bird connection, Dinosaur - Evidence for Cenozoic dinosaurs, Dinosaur - Bringing dinosaurs back to life, Dinosaur - Discovery of probable soft tissue from dinosaur fossils, Dinosaur - Extinction theories, Dinosaur - Asteroid collision, Dinosaur - The Oort cloud, Dinosaur - Environment changes, Dinosaur - History of discovery, Dinosaur - In popular culture, Dinosaur - Religious points of view, Dinosaur - Notes and references, Dinosaur - General references

Read more here: » Dinosaur: Encyclopedia II - Dinosaur - History of discovery