Basing his conclusions mainly on a few fossil teeth and a jawbone that had been unearthed near Oxford, England, William Buckland published the first scientific description of an extinct land reptile, or dinosaur, giving it the genus name Megalosaurus.
Dinosaur fossils have been uncovered for thousands of years, but before the nineteenth century, the fossils were thought to be the bones of still-living animal species such as elephants, crocodiles, and fish. The idea that there had once existed life forms that had become extinct received little, if any, credence, mainly because Western religions maintained that the earth was young and that God would not allow his creations to become extinct.
It was not until the early nineteenth century, with the rapid development of the new science of geology, that views began to change. In 1795, Scottish geologist James Hutton
The earliest scientific documentation of dinosaurs was made in 1677 by an Englishman, Robert Plot
Before it was known that dinosaurs existed, fossils in England were being unearthed. The fossils included those of extinct, giant reptiles, marine animals such as ichthyosaurs and plesiosaurs, and a flying creature, pterodactyl, all dating to the Mesozoic era (248 million to 65 million years ago). Scientists then found a new kind of creature, similarly ancient.
Some time before 1818, William Buckland, a clergyman and professor of geology at Oxford University, obtained some bones that included several fossil vertebrae, part of a thigh bone, and a piece of jaw with a few teeth from slate quarries at Stonesfield, about twelve miles north of Oxford, in south-central England. The English surveyor and geologist William Smith (1769-1839), who had mapped the geological strata of England, had shown that the strata in which the bones were found by Buckland dated to the mid-Jurassic period of the Mesozoic. (Scientists have since determined that Jurassic strata are 206 million to 144 million years old.)
In 1818, Cuvier examined the Stonesfield fossils. He knew that, although the leg bones bore some resemblance to those of mammals, no fossils of mammals had been found that were from the Jurassic. In addition, Cuvier noted the teeth did resemble, but were much larger than, those of a monitor lizard, an existing, carnivorous, terrestrial reptile. Cuvier therefore concluded that the fossils belonged to a previously unknown and gigantic carnivorous land reptile. The fossils were too fragmentary to provide a clear idea of the animal’s appearance, however.
Buckland waited six years to publish the discovery of the Stonesfield fossils. Meanwhile, duirng the early 1820’s, English physician-paleontologist Gideon Mantell unearthed teeth from another great land reptile from strata dating to the early Cretaceous period (beginning 144 million years ago), in Sussex, England. Mantell observed that the teeth of this creature differed from those of the carnivore discovered by Buckland. Mantell concluded that his creature was a plant eater, or herbivore.
Finally, on February 20, 1824, Buckland announced the discovery of the Stonesfield fossils in a paper read to the Geological Society of London. Based mainly on the teeth and lower jawbone, he described the creature as an extinct, giant, carnivorous, terrestrial “lizard.” He named the animal megalosaurus, drawing on the Greek words megalo, for great, and saurus, for lizard. It was the largest land reptile, living or extinct, to be identified up to that time. Buckland, however, did not invent the name megalosaurus. James Parkinson
Georges Cuvier.
Later in 1824, the Geological Society published Buckland’s description of megalosaurus in its journal Transactions of the Geological Society. The following year, Mantell formally announced the discovery of the first giant, extinct, land-dwelling, herbivorous reptile, which he named iguanodon. Although Buckland’s and Mantell’s announcements constituted the earliest published scientific descriptions of dinosaurs, these creatures had not yet been recognized as belonging to a distinct group and the term “dinosaur” had not yet been invented.
In 1842, English paleontologist Richard Owen reviewed the fossil evidence of the three species of large, extinct, land reptiles that had by then been confirmed by multiple specimens: megalosaurus, iguanodon, and a species that Mantell had discovered in 1833, hylaeosaurus. Noting the similarity in hip structure, Owen placed all three in a previously unrecognized order or suborder of reptiles. Owen called this new category the dinosauria, from the Greek dino, meaning fearfully great, and saur, lizard. Up to that time, eight other fossil reptiles had been named that would later be transferred to the dinosauria category. An important distinguishing characteristic of dinosaurs is that their legs are tucked in beneath their bodies, providing greater support than the legs of other reptiles, which project from the sides. Thus, dinosaurs, generally, had been able to walk and run more efficiently than had other reptiles.
William Buckland’s scientific description of the fossils of a long-extinct, giant, terrestrial reptile launched paleontology, the scientific study of past life as known from fossilized elements. The full significance of the early dinosaur discoveries came only after many years, however. The initial import of the discoveries was that they added to the mounting tally of species that had become extinct, and they established that giant reptiles had once roamed the land. The discoveries grew in significance when Richard Owen recognized these fossil reptiles as belonging in a new, separate taxonomic category called dinosaurs.
Later, the hunt for dinosaurs spread from Great Britain to the United States, then to the rest of the world. Paleontologists unearthed fossils of many new species, revealing that dinosaurs were a very large, diverse, and important group of animals. Eventually, scientists determined that many dinosaurs were intelligent and some nested colonially and cared for their young. As of the early twenty-first century, more than one thousand species of dinosaurs had been discovered, and scientists anticipated the discovery of many new genera and species.
Dinosaurs dominated life on land for approximately 160 million years, spanning much of the Mesozoic era, from the late Triassic period to the end of the Cretaceous period. Their dominance gave the Mesozoic its epithet, the “age of reptiles.” At the end of the Cretaceous, dinosaurs—or at least most of them—became extinct. Many paleontologists believe that these creatures left a living legacy: birds. Mounting evidence during the late twentieth and early twenty-first centuries indicates that birds descended from a small, carnivorous dinosaur.
-
Buckland, William. “Notice on the Megalosaurus or Great Fossil Lizard of Stonesfield.” Transactions of the Geological Society 1, ser. 2 (1824): 390-396. The first published scientific description of a dinosaur. -
Cadbury, Deborah. Terrible Lizard: The First Dinosaur Hunters and the Birth of a New Science. New York: Henry Holt, 2001. Details the drama surrounding the early dinosaur discoveries. -
Farlow, James O., and M. K. Brett-Surman, eds. The Complete Dinosaur. Indianapolis: Indiana University Press, 1997. Chapters 1 and 2 of this comprehensive volume treat early dinosaur discoveries. -
Larson, Edward J. Evolution: The Remarkable History of a Scientific Theory. New York: Modern Library, 2004. A broad overview that includes discussion of early dinosaur fossilists. -
McGowan, Christopher. The Dragon Seekers: How an Extraordinary Circle of Fossilists Discovered the Dinosaurs and Paved the Way for Darwin. Cambridge, Mass.: Perseus, 2001. Describes early discoveries of dinosaurs and the debate over the origin of species. -
Spalding, David A. E. Dinosaur Hunters: Eccentric Amateurs and Obsessed Professionals. Rocklin, Calif.: Prima, 1993. Chapter 2 discusses the early British fossilists.
Lamarck Publishes Zoological Philosophy
Scientists Study Remains of Giant Moas
Lyell Publishes Principles of Geology
Archaeopteryx Lithographica Is Discovered
Louis Agassiz; Georges Cuvier; Sir Edwin Ray Lankester; Sir Charles Lyell.