Meaning, "fearfully-great lizard", is a general name for two orders of extinct reptiles, the "lizard-hipped" Saurischia and the "bird-hipped" Ornithischia. Certain types of saurischian dinosaurs were the largest animals ever to live on land.

The word dinosaur really does not mean "terrible-lizard"; in fact, it was originally defined to mean "fearfully-great lizard", by Richard Owen in 1842. The Greek word deinos, when used as a superlative, means "fearfully-great"; as used by Homer in The Iliad. It became simplified over time, as a simple adjective, to mean "terrible". In reality, scientists believe that dinosaurs are neither "terrible" nor "lizards".

When the secrets of prehistoric life were unearthed, scientists tried to picture the feelings of those confronted by the great monsters whose fossil bones were coming again to light. Sir Richard Owen (English, 1804-1892) named a few of these creatures, from Greek words. So, there was the terrible (fearful) lizard (Greek, deinos, "fearful", plus sauros, "lizard").

Sir Richard Owen was an English zoologist and paleontologist (palaeontologist, British). In 1856, he was appointed superintendent of the natural history department of the British Museum and was instrumental in the establishment of the separate British Museum (Natural History), now the Natural History Museum, becoming its first director in 1881.

In addition to all of his important scientific publications, Sir Owen named and reconstructed numerous celebrated fossils, including the giant moa bird Dinornis, the dinosaur Iquanodon, and the earliest bird, the Archaeoptryx.

Dinosaurs are the best examples of success and adaptation known. They ruled the Earth longer than any other land animals, including humans (about 150 million years), and introduced birds.

Dinosaurs and "humans" did not coexist. The death of the last dinosaur and the appearance of the first "human" (genus homo) are said to have been separated by about 64 million years; in other words, dinosaurs existed in the Mesozoic era while mankind lived in the Cenozoic era; so, authorities maintain that mankind did not exist in the same time period as the dinosaurs.

The Mesozoic era is defined as "belonging to, or designating the third era of geologic time, including the Cretaceous, Jurassic, and Triassic periods and marked by the predominance of reptilian life forms."

The Cenozoic era, is said to be "of or belonging to, or designating the latest era of geologic time, which includes the Tertiary and Quaternary periods and is marked by the evolution of mammals, birds, plants, modern continents, and glaciation."

Mankind could not feel too self assured about the absence of threats from dinosaurs. If the dinosaurs could not touch them, there were plenty of other deadly dangers in their own era.

Dinosaurs were not "warm-blooded" like modern mammals, nor were they "cold-blooded" like modern lizards. Most specialists believe that dinosaurs were "dinosaur-blooded", a condition that combines "warm-bloodedness" with a changing metabolism over the animal's lifetime. A new unofficial term, metathermy, has been proposed for this condition in Mesozoic dinosaurs.

Popular books, movies, and TV specials are not necessarily accurate; in fact, they often contain errors and outdated information, and may reflect the personal bias of the writer. Most dinosaur books and TV scripts are not reviewed by professional dinosaur paleontologists for accuracy.

All of the various kinds of dinosaurs did not live and die at the same time. The distance in time between Tyrannosaurus and Apatosaurus (formerly called "Brontosaurus") is the same amount of time as between Tyrannosaurus and the first humans, about 65 million years.

Of the (approximately) 350 known mesozoic dinosaurs, only one to two dozen species faced the final extinction in North America.

Mammals did not evolve from the dinosaurs, and there is no evidence that they helped drive the dinosaurs into extinction by eating their eggs. Mammals and dinosaurs both appeared in the Upper Triassic Period.

Did an asteroid (or comet) kill the dinosaurs? The "asteroid theory" of dinosaur extinction has not been proven nor solved. "Proof" that an asteroid hit the Earth at the end of the Cretaceous does not automatically prove that it killed the dinosaurs. Most dinosaur specialists (most articles on this topic are written by non-dinosaur specialists) are willing to accept that an asteroid hit the Earth, but not that it was the one cause of the Mesozoic extinctions.

The remaining unsolved question is when did the asteroid hit? Was it before, during, or after the "classic dinosaurs" went extinct? It should be remembered that birds are the direct descendants of one dinosaur group, the Theoropoda; so in a way, dinosaurs are not completely extinct.

All big "monster" reptiles from the prehistoric past are not dinosaurs. They represented less than 10% of the 40 groups of reptiles from the Mesozoic Era. Pterodactyls, sea-serpents, giant lizards, pelycosaurs, and other big prehistoric beasts are not dinosaurs. "Monsters" and Dragons are the products of fiction and mythology while dinosaurs were real.

Archaeologists do not dig up dinosaurs. Archaeology (a subdivision of Anthropology) deals only with mankind and covers the last four million years. Paleontology (a combination of Geology and Biology), deals with all fossils and covers the last 3.5 billion years!