Illinois-born Stephen Brusatte is one of the stars of modern paleontology. A former National Geographic grantee, he has discovered 10 new dinosaur species. He has also led groundbreaking scientific studies that have rewritten the history of these magnificent creatures which, thanks to Hollywood and countless children stories, haunt our imaginations today like never before. I think you could show a picture of T.
And so many people are studying T. It is a Mesozoic muse for a lot of scientists, me included! New technology is helping a lot. Probably the best example of that is CAT scanning, which we can use to look inside dinosaur skulls.
This has revealed the brain, the sense organs, sinuses, blood vessels, and nerves that are hidden inside the skull of T. We can build digital models , which reveal that it had a pretty large brain! Its brain size relative to its body was somewhere in the range of chimps, so it was a smart animal, much smarter than people give it credit for. Its brain also had huge olfactory bulbs, so it was a great smeller and sniffer.
It would have used its nose to seek out its prey. We can also tell from its inner ear, the cochlea, that it was really good at hearing a whole range of sounds, including low-frequency ones. It had big, forward-facing eyes and big regions of the brain that controlled the sense of sight. It was an animal that had not only brawn, but brains as well. Right now is the best time in the history of dinosaur research. People are finding more dinosaurs nowadays than ever before: about 50 new species a year, which is incredible.
Not a new bone or skeleton, but a totally new species. A big part of the reason is that many places around the world have opened up over the last few decades, like China, Mongolia, and Argentina—vast countries with lots of deserts and mountains, full of rocks bursting with dinosaur bones.
A lot of those places were very hard to work in a few decades ago for western scientists. Now you have this huge group of young people in China, Argentina, and other places, studying dinosaurs. China is the hot spot. Probably about half the new dinosaur species are coming from there.
One of the species is Jianianhualong. It was a raptor dinosaur. Feathers probably evolved to keep dinosaurs warm and wings probably first evolved as display structures, like advertising billboards. Only later were they co-opted into air foils.
When you think of dinosaurs, you think of places like Mongolia or the Badlands of the western United States, so when I moved to Scotland about five years ago I knew I was coming to a place where it would be difficult to find dinosaurs. But I did know that there was one place in Scotland that had started to yield some tantalizing clues: little bits of dinosaur bones, teeth, and footprints. This is the Isle of Skye , a majestic, enchanted island off the west coast of Scotland, with a Tolkien-esque landscape.
It was much warmer and equatorial, more like Florida or Spain today, and it was bursting with dinosaurs! Their bones were preserved in the rivers, deltas, and lagoons of the island. Setting the Scene In the last investigation, students noted that some parts of organisms are more likely to become fossils than others. Start the investigation by asking students to think about this question: Based on what you learned from the last investigation, what kinds of things become fossils?
Ask them the following: Describe the changes that seem to be happening to the decomposing fruit. What do you think is causing these changes? How long will the fruit continue to decompose? What will eventually happen to the fruit? What do you think is the likelihood of the fruit becoming a fossil, either all of it or part of it?
When would the fruit be more likely to become a fossil — if it decomposed quickly, decomposed slowly, or did not decompose at all? Presenting the Investigation Question After the scene is set, introduce your students to the investigation question: Why do some things become fossils, but others do not? Have your students brainstorm ideas about how this investigation question could be investigated. How would you design an experiment that could be used to test the investigation question?
What materials would be needed? What would you have to do? What would be measured? How long would the experiment take? Here are some initial questions that your students can discuss, in pairs, then in groups: What happens when a living thing rots or decays? Why do some things, like fruit, rot or decay? Do all living things decay? Why or why not? Do all parts of living things decay? How could the decay of a living thing be slowed down or stopped? What impact does decay have on how a fossil forms?
Have your students share their ideas with the class and record them as a list on a flipchart. Ask students the following: What would you like to learn about why some things become fossils, but others do not? Exploring the Concept Have students cover their desks with newspaper or newsprint. Explain to students that they will be exploring different ways to preserve a piece of plant material, in this case, slices of banana. Tell them that they will be placing the banana slices in paper cups and covering them with different materials.
They will let them sit overnight. The next day, they will look for any changes that may have occurred. Present to students the different materials for preserving the banana slices: soil, sand, gravel, and plaster of Paris. Have students predict how the slices will change in each of the materials. Record predictions on the whiteboard or flipchart. Ask students to write their names on each of the cups.
Ask students to partly fill the cups with each of the materials. They should then place banana slices in each cup and cover them with more of each material. Have students place one slice of banana in an empty cup to be used as a control to compare with the other samples. Have students place the slices on a counter where they can be collected the next day.
The next day, have students remove the slices from each of the materials. The slices in the Plaster of Paris will have to be cracked open with a hammer. Be sure that students wear impact goggles when doing this, or you should do this yourself.
For the next decade, Bailleul worked with Horner, Schweitzer, and their colleagues to study the fossils, treating the endeavor as a long-term side project. In , the team got an unexpected confidence boost when a Swedish group announced that it had found a million-year-old fern with fossilized nuclei and chromosomes.
This nearly whole, deep-black skull belongs to the most complete specimen of Tyrannosaurus rex on display in Europe, an individual nicknamed Tristan Otto. First, the researchers applied chemical stains to the fossils that bind to cartilage, which suggested that the developing bits of dinosaur skull had not yet hardened into bone when the animals died, as the team suspected.
Bailleul and Schweitzer then isolated some of the fossil cells and applied propidium iodide and DAPI, two chemical stains widely used in medical research to visualize fresh DNA. Unsurprisingly, the emu cells better attracted the stains—but the stains also glommed on to specific points within the fossilized dinosaur cells.
Past studies have found that genetic material disintegrates in bones after a few million years. Bones are highly porous in life, which makes them imperfect time capsules in death. The preserved dinosaur cells were probably embedded in cartilage, Schweitzer says, which lacks pores. The structure of cartilage may have protected the cells inside—and their chemical constituents—more effectively.
Bailleul and Schweitzer say that if DNA is present, it may have survived because of the formation of extra chemical bonds within different parts of a single DNA strand. In living creatures, these sorts of reactions—called crosslinking—are so toxic, some anticancer drugs induce these bonds in tumor DNA.
But during fossilization, the bonds might help stabilize DNA for the long haul. Jasmina Wiemann , a Yale Ph. Past studies have shown that DNA and histones—proteins that act as spools for genetic material— can bind to each other. She adds that more chemical analysis would be needed to confirm the idea. All rights reserved. Science News. Hints of fossil DNA discovered in dinosaur skull Scientists have spotted cellular structures—and a substance that behaves like DNA—in cartilage more than 70 million years old.
More than 70 million years ago in what's now Montana, the plant-eating hadrosaur Hypacrosaurus stebingeri roamed. A new study of H. Share Tweet Email.
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