Find what percent one number is of another.

Find what percent one number is of another

Some Arctic Dinos Lived in Herds By Sid Perkins Just as interesting, however, is how this was discovered. Scientists didn’t look at a single fossil bone. Instead, they analyzed a large number of preserved footprints on a mountainside located toward the southern end of central Alaska. Anthony Fiorillo works at the Perot Museum of Nature and Science in Dallas, Texas. As a vertebrate paleontologist, he studies the fossils of creatures with backbones. In 2007, he was part of a research team exploring Denali National Park. “We rounded the corner and there they were,” he recalls. Thousands of footprints had been preserved in stone. “It was amazing.” Dinosaurs died out more than 65 million years ago (not counting birds, their modern-day relatives). So, it’s a bit surprising that scientists know so much about these ancient creatures. Now, a new study reveals that a certain type of duckbilled dinosaur lived in the Arctic year-round. These animals also traveled in herds that included many age groups, they find. The creatures even appear to have gone through a “teenage growth spurt.” Those tracks pepper a steep patch of exposed rock about twice as long as a football field and up to 60 meters (roughly 200 feet) wide. They sit at least 160 kilometers (100 miles) north of the Gulf of Alaska. Between 69 million and 72 million years ago, that now-rocky material was muddy sediment on a floodplain near a seacoast, Fiorillo explains. The hadrosaurs walked across the squishy mud. Later, the footprints they left turned to stone. Previous studies suggested adult duckbills took care of their young, says Fiorillo. The new evidence that these dinosaurs truly traveled in herds with multiple age groups confirms that parents cared for their young well beyond the time they left the nest, his team concludes. The researchers published their findings June 30 in Geology. © Science News for Students Thousands of tracks cover this rocky mountainside in Alaska’s Denali National Park. They provide a wealth of information about the size, age and lifestyle of certain dinosaurs. COURTESY OF PEROT MUSEUM OF NATURE AND SCIENCE EVIDENCE FOR HERDS O F DINOSAURS Small meat-eating dinosaurs called theropods had left behind a few of the tracks that Fiorillo’s team found in Denali. Birds had left some others. But the vast majority came from creatures called hadrosaurs. These large plant-eating duckbilled dinosaurs had been quite common during the Cretaceous Period. That helps explain one of their nicknames: “cattle of the Cretaceous.” For the new study, the researchers focused only on the hadrosaur tracks. More than half of the footprints were preserved so well that they had clear impressions of the skin on the dinosaurs’ feet. Most tracks had a similar level of preservation. That suggests all were probably left within a short period. Other fossils in the nearby rocks, including insect burrows, suggest these hadrosaurs had left their footprints during the summer. These are trace fossils — evidence of ancient life other than a preserved carcass or bone. At the time these dinosaurs lived, Fiorillio says, the average temperature in the warmest months was between 10° and 12° Celsius (50° and 54° Fahrenheit). That’s about what conditions are like today along the border between Canada and the lower 48 U.S. states, he notes. The team measured a large sample of the duckbills’ footprints. They fell into four distinct size ranges. The largest tracks, presumably made by adults, measured about 64 centimeters (25 inches) across. The smallest tracks, 8 centimeters (3 inches) wide, were likely left by young duckbills. They would have been no more than a year old. Tracks of two other size groups were probably made by juveniles and near-adults. These data suggest the community of hadrosaurs included four different age groups. © Science News for Students A hadrosaur footprint made roughly 70 million years ago. For scale, the long blue bar at right is 10 centimeters long; each small blue or white bar measures 1 centimeter. COURTESY OF PEROT MUSEUM OF NATURE AND SCIENCE © Science News for Students THESE DINOSAURS DIDN’T MIGRATE About 84 percent of the tracks sampled for the new study had been left by older hadrosaurs — adults or near-adults. Roughly 13 percent came from the youngest members of the herd. And a mere 3 percent came from herd members considered to be juveniles, says Fiorillo. The rarity of tracks by these tweens suggests that the young of this species had a rapid growth spurt. If true, they would have spent relatively little time at this vulnerable size — and therefore left very few tracks. “What’s really neat is how many small tracks there are,” notes Anthony Martin. An ichnologist — or expert in trace fossils — he works at Emory University in Atlanta, Ga. Other scientists had analyzed fossil bones from duckbills. These studies had hinted that the equivalent of adolescent hadrosaurs would have experienced growth spurts. But the new findings are “the best evidence that I’ve seen,” says Eric Snively. He’s a vertebrate paleontologist at the University of Wisconsin- La Crosse. “This is a great study,” he adds, “and further evidence that juvenile hadrosaurs grew up in an eye-blink.” Also previously, researchers had proposed that Arctic dinosaurs migrated farther south for the winter. That’s because even if the region was much warmer than it is today, nights in the high Arctic would have been 24 hours long. So, with no sunshine for several months, Alaska would have had long periods of very bleak, chilly weather. But finding juveniles in the herd strongly suggests that these dinosaurs remained in the Arctic all year. That’s because adolescents and preadolescents wouldn’t have had the strength or stamina to make those long treks, Fiorillo maintains. Field work is often harsh. Paleontologists studying the dinosaur footprints here on an Alaskan mountainside sometimes worked in cold and fog. COURTESY OF PEROT MUSEUM OF NATURE AND SCIENCE © Science News for Students The presence of very young dinosaurs might have been expected, he notes: If this were a nesting region, the babies would have hatched sometime just before summer. And remember, that’s when these tracks were left. But that wouldn’t explain the juveniles, he says. The team’s findings “suggest that these dinosaurs were overwintering in Alaska somehow,” says Snively. At the time, the average temperature in the region remained above freezing even during the winter, he notes. But, he adds, “this study raises interesting issues about how the dinosaurs could live in the region when it was pretty dark for several months at a time.”

Groundhog Goes Outside It was the deep of winter. Gus was worried. He couldn’t find his shadow anywhere. “Have you seen my shadow?” Gus asked Dad. “When did you see it last?” Dad asked. “Have you seen my shadow?” Gus asked Mom. “Go back, step by step, until you find it,” Mom said. “Have you seen my shadow?” Gus asked Grace. “Try looking where you left it,” Grace said. Gus stopped looking. He began to shout: “HAS ANYBODY SEEN MY SHADOW?” “Have you tried looking outside?” asked Dad. Gus hadn’t been outside in months. He hadn’t seen his shadow in months. Maybe his shadow was outside! Gus left the burrow and went outside. As soon as he did, someone began to cheer. Children waved and jumped up and down. People shot photos of him. They all looked really happy. Gus forgot about his shadow. Gus was a star! Back in the burrow, his family gathered around him. Gus grinned from ear to ear. “Did you find it?” asked Mom. “Find what?” asked Gus.

I'd Like to Be I'd like to be a happy clown and make everyone laugh. I'd wear big clothes, and a bright red nose, and be pleased with all I have. I'd like to be an athlete, and play basketball each day. I'd leap so high I could touch the sky, and make baskets along the way. I'd like to be a gardener and grow healthy things to eat. I'd plant my seeds, water them, and pull weeds. My garden would be hard to beat. I'd like to be a mermaid and swim in the deep blue sea. The fish and whales could tell their tales, while dolphins sang to me. I'd like to be a cowboy and ride horses every day. And then at night, I would tie them tight and feed them lots of hay. I'd like to be a dancer and twirl and jump and fly. I'd wear fluffy skirts and fancy shirts. People would clap as I danced by. I'd like to be an artist and try to paint the land. I would paint the water blue and the great skies, too. The ground would be the color of sand. I'd like to be a pirate. I would have to be brave and bold. I would sail with a crew on oceans of blue to look for treasure and gold. I'd like to be an astronaut and fly up to the moon. In outer space, I'd find a place to eat without a spoon. I'd like to be a zookeeper and care for birds and snakes. I'd give them food, and watch their moods, and on birthdays give them cakes. I'd like to be a musician and play songs every day. I would play the trumpet, or guitar and strum it, making music my own way. The moral of this lesson is to be what you can be. Dare to dream, and listen to your talents to find what you will be.

Do you know where do the things around us get the energy they are using? How about you? Where do you get the energy you need to do your daily activities? Do you remember what we have discussed in Unit 4? Very good! OBJECTIVES: - Names the sources of energy. - Classifies the different sources of energy. SCIENCE 2 – MODULE 6 SEIBO COLLEGE 4 Energy allows us and all the things around us to move, work and become useful. Different things use different sources of energy. Let us find out what are these sources. Let us begin with the major source of energy, the sun. Sun The sun is most important and the main source of energy on earth. It makes the day hot, dry and bright. It can also help in… a. drying our clothes b. growing of plants Do you know that the sun is a star? Yes, the reason why we could see it during day time is that it is the nearest star to our planet. Electricity Electricity allows electrical appliance work. SCIENCE 2 – MODULE 6 SEIBO COLLEGE 5 Fuel Fuel makes different kinds of vehicles move. We use different kinds of vehicles to transport us from one place to another place. Food Like what we have discussed in unit 4, we get the energy we need to do our daily activities from the food we eat.

Different approaches to thematic analysis Once you’ve decided to use thematic analysis, there are different approaches to consider. There’s the distinction between inductive and deductive approaches: • An inductive approach involves allowing the data to determine your themes. • A deductive approach involves coming to the data with some preconceived themes you expect to find reflected there, based on theory or existing knowledge. Ask yourself: Does my theoretical framework give me a strong idea of what kind of themes I expect to find in the data (deductive), or am I planning to develop my own framework based on what I find (inductive)? There’s also the distinction between a semantic and a latent approach: • A semantic approach involves analyzing the explicit content of the data. • A latent approach involves reading into the subtext and assumptions underlying the data.

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