How Does This Science Work

What is Evolution?

A Brief Introduction to the concept.

Did Dinosaurs Really Have Feathers?

Learning the reason some dinosaurs needed feathers.

Dinosaurs and Birds are related?

Making the connection between the two species

Includes a word search puzzle, coloring page and dinosaur stickers!

Table of Contents Introduction…………………………………….2 What is Evolution?..........................................................3 What Is This Animal?......................................................4 Dinosaurs had Feathers?...............................................5 Dinosaurs and Birds are Related?.................................6 What We Learned………………………………..8 Crossword Puzzle………………..……………..10

About this Issue: The Dinosaurs issue is a special edition of the How Does This Science Make Sense? series, which discusses the science behind bizarre and unbelievable facts about dinosaurs, with reference to real scholarly articles and evidence. This issue discusses three new and interesting facts about dinosaurs you haven’t heard before.

These magazines are meant for 9-12 year olds, but can be read by any age to help introduce and spark an interest in science beyond the lessons they learn from a textbook, since these issues are discussed based on current events about new discoveries.

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Evolution is a process in which one living thing called an organism changes over a long period of time into a different and sometimes more complex one. When an animal “evolves�, it changes into a more complex animal – sometimes even a different one!

This process might be familiar to you if you learned where humans came from. Science supposes that humans may have evolved from apes, which means humans are related to them. For many years, apes have slowly developed into a new and other type of organisms, which is how humans found a place on Earth today. These new words will be crucial when learning and understanding these new facts.

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This is the oldest type of bird – or dinosaur; it is known as the Archaeopteryx. This animal is known to have a lightweightfeathered body, a long, straightfeathered tail, a long neck, long legs, long arms and feathers on the wings. This bird’s fossils make scientists think it developed between the time of the dinosaurs and when birds were on Earth. This bird had three clawed fingers on each hand, toothed jaws like dinosaurs and wings with well-developed flight feathers, similar to birds seen today.

This bird however had different types of feathers compared to modern birds. The Archaeopteryx’s feathers were thinner and weaker, meaning these birds were weaker when they needed to fly. Scientists made this observation when looking at the bone structure of this fellow. They found that these birds lacked a certain bone with larger flight muscles and their shoulder joints prevented these birds from lifting their wings far enough to fully flap them. The feathers were also seen to be unusually narrow in size when compared to modern birds.

So, scientists made the conclusion that these ancient dinosaur birds could glide rather than fly; flapping wings for a good takeoff was not going to happen easily.

Archaeopteryx would have flown best by jumping off a high place and soaring like a paper airplane.

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Although you thought most dinosaurs were scaly like alligators today, some dinosaurs actually had feathers. The dinosaurs with this feature were called the Similcaudipetryx; these dinosaurs lived during the Cretaceous Period - that was between 65 million and 145 million years ago!

Scientists made the discovery when comparing fossils of a juvenile and an adult that the feathers changed with age. The fossil of the younger archaeopteryx showed that it had small ribbon-like wings and tail fathers. The adult, however, had taller/longer feathers resembling quills.

This picture above shows what the feathers looked like. These fossils show that the feathers developed in dinosaurs and later birds over time.

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Science has shown that certain features of birds – including their large heads, eyes, braincase and beak – evolved through a process called paedomorpohsis. That is when an adult keeps certain traits only seen in young members of the species. Scientists looked at the skulls of dinosaurs and compared these skulls to other animals. The skulls of birds appeared to look similar to the skulls of younger dinosaurs. These animals are known as archosaurs because they have the same type of skull.

This can be seen when comparing the skulls of juvenile and adult of the alligators, a species of dinosaurs named the Coelophysis and the older species of birds, Archaeopteryx.

Skulls of younger animals | Skulls of older animals

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The pictures show that small changes happened in the development of both juvenile and adult alligators and dinosaurs. However, while the skulls may appear almost identical in appearance, you can see how the skull of the younger alligator looks similar to the adult bird, while the juvenile alligator skull has more differences in appearance to the adult alligator.

When looking at the other features of the bird besides the head however, we could see that the bird does not show any signs of padeomophosis (or having the juvenile traits) in the pictures below of the Confuciusorinis bird. We could see that some features of the bird body are similar to the features of dinosaurs but that they seem to show an addition of development past the adult stage. This is because the brains of these dinosaurs are genetically independent of the rest of the skeleton. This means that the brain can evolve independently, so the process of paedomorphosis could have involved genetic changes affecting only the skull.

A fossil of the Confuciusornis bird

An image of the Confuciusornis’s appaearance

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Archeopteryx birds dinosaurs evolution

feathers paedomorphy Similicaudipteryx skull 8

The Archeopteryx

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Write down three things you learned while you read this magazine.

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2.)______________________________________________________________

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3.)______________________________________________________________

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