what we have learned and what we still don’t know

(CNN) — Huge fossilized bones discovered in slate quarries in Oxfordshire, England, dating back to the late 17th century, immediately raised eyebrows.

In a world where evolution and extinction were unknown concepts, experts of the time searched for an explanation. Perhaps, they thought, they belonged to a Roman war elephant or a giant man.

It was not until 1824 that William Buckland, the first professor of geology at Oxford University, described and named the first known dinosaur, based on mandibles, vertebrae and limb bones found in local quarries. The largest femur was 33 inches long and nearly 10 inches in circumference.

Buckland named the creature to which the bones belonged Megalosaurus, or huge lizard, in a scientific paper he presented to the newly created Geological Society of London on February 20, 1824. over 40 feet (12 meters) long and “the volume of an elephant.” Buckland thought it was probably an amphibian and lived partly on land and in water.

“In a way, he got a lot of things right. They were a group of extinct giant reptilian creatures.
It was a radical idea,” said Steve Brusatte, a paleontologist at the University of Edinburgh and author The Rise and Fall of the Dinosaurs: A New History of Their Lost World.

“We all grew up watching cartoons about dinosaurs and watching Jurassic Park with dinosaurs in our lunchboxes and toys. But imagine a world where the word ‘dinosaur’ doesn’t exist, where the concept of ‘dinosaur’ doesn’t exist, and you were the first people to realize that just by looking at the big bones on Earth.”

The word “dinosaur” did not appear until 20 years later, coined by anatomist Richard Owen, founder of the Natural History Museum in London, based on common characteristics he identified in his research. Megalosaurus and two more dinosaurs, Iguanodon And Hyleosauruswhich were first described in 1825 and 1833, respectively.

Article about Megalosaurus It established Buckland’s professional reputation in the new field of geology, but its importance as the first scientific description of a dinosaur became apparent only in retrospect.

At that moment, Megalosaurus was overshadowed in the public imagination by the discovery of complete fossils of giant marine reptiles such as an ichthyosaur and a plesiosaur, collected by paleontologist Mary Anning off the coast of Dorset, England. No complete skeleton was found. Megalosaurus.

But Megalosaurus influenced popular culture. Charles Dickens, a friend of Owen’s, imagined encountering a megalosaurus on the mean streets of London at the beginning of his 1852 novel. Deserted house.

The illustration shows geologist William Buckland teaching in a lecture hall at Oxford University on 15 February 1823. (Metropolitan Museum of Art)

It was also one of three dinosaur models exhibited at London’s Crystal Palace in 1854, home to the world’s first dinosaur park. It’s still there today. Although the shape of its head is generally correct, today we know that it was about 6 meters (about 20 feet) long and walked on two legs rather than four.

Who was Buckland?

It is unclear how Buckland developed his expertise as a geologist.

An ambitious and charismatic scholar, he read classics and theology at Oxford, graduating in 1805, and took a wide range of subjects, including anatomy, says Susan Newell, a historian and research fellow at Oxford University’s Natural History Museum. He also maintained contacts with other famous natural scientists of the time, such as Charles Cuvier in France, famous for his work comparing living animals with fossils.

“(Buckland) was the first person to really start to think seriously about what was going on with all these strange fossils that were turning up right on the street in this quarry in Oxford, and he started paying local quarrymen to find them.” fossils and) … leave things for him,” Newell said. “He started putting the puzzle together.”

A year after the publication of his article about MegalosaurusBuckland married his unofficial assistant, Mary Morland, who was a talented naturalist and fossil illustrator in her own right. Megalosaurus it appeared in a groundbreaking article.

Later in his career, Buckland accepted that much of the United Kingdom had once been covered in ice sheets after a trip to Switzerland, realizing that a glacial period had shaped the British landscape rather than the biblical flood.

Dinosaur statue Megalosaurus in London’s Crystal Palace Park, dating from 1854. At the time, paleontologists thought the prehistoric creature walked on four legs. (Loop Images Ltd/Alamy Stock Photo)

Newell said Buckland’s academic career ended prematurely due to some mental crisis that prevented him from teaching. He died in 1856 in a London asylum.

What have we learned about dinosaurs?

For paleontologists, the 200th anniversary of the dinosaur’s first scientific name is an opportunity to take stock and look back at what the field has learned over the past two centuries.

Dinosaurs were once considered evolutionary failures due to their extinction. In fact, dinosaurs survived and thrived for 165 million years, which is much longer than the approximately 300,000 years during which modern humans roamed the planet.

Today, about 1,000 species of dinosaurs have been named. According to Brusatte, about 50 new species of dinosaurs are discovered every year.

“In fact, science is still in the discovery stage. Yes, it’s 200 years old now, but we’ve only found a fraction of the dinosaurs that once existed,” Brusatte said. “Today’s birds are descendants of dinosaurs. Currently, more than 10,000 species of birds live here. And of course, dinosaurs lived for over 150 million years. Then count. “There were probably thousands, if not millions, of different species of dinosaurs.”

In the 1990s, fossils discovered in China conclusively showed that dinosaurs had feathers, confirming the long-held theory that they were the direct ancestors of backyard birds.

It is not just amazing fossil discoveries that make the current golden age of paleontology. New technologies such as CT scanning and computational methods are allowing paleontologists to reconstruct and understand dinosaurs in much more detail.

Jaw engraving Megalosaurus based on drawings by Mary Morland Look out for Megalosaurus or the great Stonesfield fossil lizard. 1824, William Buckland.
(Image collection/Alamy)

For example, some bird fossils preserve small structures called melanosomes that once contained pigment. By comparing melanosomes with those of modern birds, scientists can determine possible original feather colors.

We still have a lot to learn. It is not entirely clear how and why dinosaurs became so large, and it is also unknown what sounds these creatures could make.

Today paleontologists believe that Megalosaurus I would walk on two legs. (Julien Behal/PA Wire/AP)

“I think it’s almost impossible for us to imagine a world in which people didn’t know about dinosaurs,” Brusatte said.

“However, there will be things in the future that people will say we didn’t know about in 2024. (This anniversary) should give us a little perspective.”

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button