Megalosaurus, the fossil that introduced dinosaurs to the world
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Two hundred years ago, on February 20, 1824, the description of a dinosaur was first published. William Buckland, the first professor of geology at Oxford University, presented his paper describing it to the Geological Society. Was it the famous Tyrannosaurus rex? Or the movie-made-popular velociraptor? No on both counts. But the name "dinosaur" wasn't given until two decades later, and the actual discovery of the dinosaur fossils that Buckland talked about had been made 125 years earlier! Let's see what the story is behind Megalosaurus.
People around the world have been looking at tracks, fossilized bones, teeth, and plants for hundreds of years. Some of the finds were mistakenly thought to be dragons, unicorns, giant humans, or simply the incorrect living animals of the day. Some felt that the plant or seashell imprints in stone were just crystallized minerals or stone itself and not relics of living things from the past. However, mineral analysis by Fabio Colonna in 1606-1616 demonstrated that were organic origins.
Here and there in England, largely from a limestone quarry in Stonesfield, England, a few bones and fragments were discovered in the 17th and 18th centuries which may have been from Megalosaurus. Naturalist Robert Plot was the first curator of the Ashmolean Museum of Art and Anthropology in Oxford, England. In 1676, he collected a bone fragment from the local area and at first thought it was from a Roman military elephant and then a giant human. Later, physician Richard Brookes redrew Plot's illustration in the 1763 issue of A System of Natural History and labeled it with the Latin name Scrotum humanum (using the newly created scientific naming system from Linnaeus in 1758). Some people think this may have been the first Megalosaurus fossil.
A few years earlier in 1755, James Platt, a collector of oddities and artefacts, found three vertebrae from the same English quarry as Plot's bone fragment. He sent them to a botanist that never examined them but instead lost them. Three years later, Platt found a thigh bone 74 cm (2 ft. 5 inches) long with a shaft 10 cm (4 inches) thick. This, too, has been lost.
At this period of time, the idea of life changing or completely dying off was unknown. People simply thought animals stayed the same, and newly found ones including fossils were simply animals that had not been discovered living elsewhere. The concept of animals going extinct wasn't even proposed until 1813 when Georges Cuvier recognized bones in North America were from a mastodon, and a skeleton in Argentina was a creature called Megatherium, a previously unknown giant sloth 2.1 m (6 ft 11 in) tall and 6 m (20 ft) long. But these are not dinosaurs. Another scientific concept unknown at the time was evolution. This was put forth by Charles Darwin in 1858.
From the 1500s to the 1800s, the prevalent thought about the age of the Earth was taken from the Bible, and that implied 6,000-10,000 years old. There was no radiometric dating of any kind until the 1940s-1960s. In the late 1800s, however, when dinosaur fossils were found, people began questioning how old the planet was. Danish scientist and Catholic bishop Nicolas Steno developed basic geologic principles in 1669. These were almost all that was known in geology related to dating the planet:
- as materials are laid down, the older layers are on the bottom tiers
- things are generally deposited horizontally
- when any given layer of rock was being formed, it was either surrounded by another solid substance, or it covered the entire surface of the earth
Steno also recognized that a triangular stone called "tongue stones" was actually an ancient shark tooth whose organic material had been replaced slowly by minerals.
As curator of Oxford's Ashmolean Museum of Art and Archaeology, English theologian, geologist, and paleontologist William Buckland (mentioned in the title article for this blog report) acquired several bones from collectors in the area of British slate nines from 1814 to 1824. He had collected a tooth, 3 vertebrae from different locations on the spine, 2 ribs, a pelvis, a pubic bone, a lower hip bone, a thigh bone, and a bone from the food (all from different specimens, not one Megalosaurus). His was the first detailed study of a non-avian (non-bird-like) dinosaur.
After consulting with Cuvier on the bones, he decided they had come from an enormous unknown lizard-like creature which he named Megalosaurus (mega = great in size, saurus = lizard) and presented his findings in 1824. However, he made two mistakes.
- He judged that it walked on all four legs. It was later shown to walk on the hind legs only. In fact, the stone statue at Crystal Palace Park (top of this blog report) is not really Megalosaurus! The shoulder hump of spinal bones identifies it as a different animal, Altispinax.
- He estimated his collection to be from something 12 meters (40 feet) long if pieced together, based on a lecture by someone studying a bigger thigh bone that they both thought (incorrectly) was from Megalosaurus. He later amended the size to 18-21 meters (60-70 feet) after calculating spinal vertebrae lengths. Currently, scientists feel its true length is 6 meters (20 feet).
Buckland also felt that because of the teeth shape, Megalosaurus was a carnivore. This went against the current thoughts from the Bible, where animals before Adam and Eve's original sin were vegetarians. He had collected a lot of bones in his studies, but not all were from Megalosaurus, which led to a lot of confusion of the day.
Richard Owen was another renowned paleontologist of the day. He took information from Megalosaurus and two other creatures known then--Iguanodon and Hylaeosaurus--which were all very similar in body structure. Based on the sacrum (bone at the end of the spine before the tailbone, and connecting to the pelvis), legs, trunk, ribs, and overall size of these three animals, Owen declared a new group of animals called Dinosauria (dinosaurs) in 1841. The "dino" in the name was Owen's interpretation as "fearfully great", but which has since morphed into "terrible".
So, many bones discovered around the same time made their way to various collectors and researchers. Although they were initially thought to be all from Megalosaurus, later studies showed otherwise. Instead of many species of Megalosaurus, there appears to be just the one named after Buckland, who studied them the most: Megalosaurus bucklandii.
Megalosaurus and other dinosaurs found their way onto commemorative stamps in the UK in 2013 to celebrate the 200-year history of paleontology in Britain and one year after the centenary of the publication of The Lost World, a dinosaur-containing novel by Sir Arthur Conan Doyle.
Megalosaurus (and Iguanodon ad Hylaeosaurus) were all honored in 2020 on a set of 50-pence coins.
Oddly enough, Charles Dickens published a short story about Megalosaurus. In Dickens' 1851 journal Household Words, English literature professor Henry Morley wrote a sort of time-traveling tale called "Our Phantom Ship on an Antideluvian Cruise" (pp. 166-176). Here is the excerpt.
We land in a warm, moist country, covered with a strange vegetation, in which fern-like palms, or palm-like ferns, Cycadaea, predominate. We have seen vegetation not unlike this when we were among men in New Zealand. There are plenty of ferns, and pines, and a few palms. Here is a land reptile, before which we take the liberty of running. His teeth look too decidedly carnivorous. A sort of crocodile, thirty feet long, with a big body, mounted on high thick l egs, is not likely to be friendly with our legs and bodies. Megalosaurus is his name, and, doubtless, greedy is his nature. Mercy upon us!
If you are interested in reading more about dinosaurs and fossil hunting, you can see six of the 44 chapters in The Complete Dinosaur book online here.
Finally, here is a timeline of dinosaur history.
