Present day dinos

This exercise is a part of Educator Guide: How Eyelashes Wick Water and Present-Day Dinosaurs / View Guide
A mottled brown and white owl -- a modern dinosaur -- perches on the glove of a handler. Dense foliage is visible in the background
Most researchers agree that birds — such as Twiggy, a barred owl at Potomac Overlook Regional Park in Arlington, Va. — descended from small theropods about 160 million years ago. Their ancestors survived the asteroid impact that wiped out all non-avian dinosaurs.A. TREMPER

Directions for teachers:
Ask students to read the introduction and the section “Some reptiles became birds” in the Science News Explores article “What is a dinosaur?” Then in class or as homework ask them to answer the first question in the “What is a dinosaur?” section.

Have a class discussion about the second and third questions in the “What is a dinosaur?” section. Then, have students break up into small groups and choose to read one of four sections from the Science News Explores article: “Dinosaurs are still alive. Today, we call them birds.” They can choose between: “The first bird,” “Not your typical dinosaur,” “Ruffling feathers,” or “Snoozing dinos.” Each section focuses on a different fossil that scientists give as evidence of the evolutionary relationship between birds and dinosaurs. As the students work in groups, have them answer the questions in the “Choose your own dinosaur” section and create a short presentation to share with the class. To create a bigger challenge, consider asking students to draw the dinosaur in the second question without the use of visual aids; you could give them the text for the section without pictures from the article.

Directions for students:
Read the introduction and the section “Some reptiles became birds” in the Science News Explores explainer “What is a dinosaur?” Then answer the questions in the “What is a dinosaur?” section as instructed by your teacher.

With your group, choose one of the four sections from the Science News Explores article “Dinosaurs are still alive. Today, we call them birds.” Choose between the sections: “The first bird,” “Not your typical dinosaur,” “Ruffling feathers,” or “Snoozing dinos.” Each of these sections focuses on a different fossil that scientists have used as evidence of the evolutionary link between birds and dinosaurs. Within your group, answer the questions below in the “Choose your own dinosaur” segment. Then create a short presentation to share with your class.

What is a dinosaur?
1. Describe how the system of classifying animals has changed. How does the system used today help scientists better understand the connection between dinosaurs and birds?

Animal classification used to be based only on physical features. Now it focuses on evolutionary relationships between species. Since birds and dinosaurs have different physical traits, they initially were not classified together. Now that their evolutionary link is better understood and the classification system has changed, researchers can better understand how other ancient creatures might be related to dinosaurs.

2. What is your reaction to the idea that birds descend from dinosaurs? Would you have expected the two species to be related?

Some students may be surprised that birds and dinosaurs are connected. Others may already know about the connection.

3. What additional questions do you still have about the evolution of birds or dinosaurs?

Student answers will vary but may include clarification on how evolutionary relationships are now defined (for instance, on things such as DNA matching, etc.).

Choose your own dinosaur
1. Which section did you read? What is the name of the dinosaur highlighted in it? Where and when was the fossil discovered?

Example answers are given for the “The first bird” section, which highlights the dinosaur Archaeopteryx. The fossil was discovered in 1861. The article doesn’t give details about where the fossil was discovered but mentions a shallow sea in what’s now Germany.

2. List all the traits of the dinosaur described in the article. Using this list, draw a picture of the dinosaur as it may have looked while it was alive. Include in your visual all of the traits highlighted in the article.

About the size of a crow, black wing feathers, arms tipped with claws, rows of teeth in its snout, flat, asymmetrical wing feathers, long bony tail, wishbone.

3. Name the behavior(s) or trait(s) of the dinosaur that can be compared to a bird. What did the behavior(s) or trait(s) allow the dinosaur to do? Explain which traits were like modern birds and which were unlike modern birds.

The fossils of Archaeopteryx show that it had flat, asymmetrical wing feathers, like those of modern birds, which could have allowed it to fly. It also had a wishbone, which modern birds also have. Unlike modern birds, Archaeopteryx had teeth, clawed wings and a long, bony tail.

4. In your own words, explain how the discovery of the fossil helped or hindered scientists’ theories about an evolutionary relationship between birds and dinosaurs.

Because of Archaeopteryx’s wishbone, scientists classified it as a bird instead of a dinosaur — even though it also had teeth, clawed wings and a long, bony tail. At the time of the fossil’s discovery, no other dinosaur had been discovered with a wishbone. Reptiles do not have that feature, so many scientists at the time saw Archaeopteryx as unrelated to reptiles (or dinosaurs) at all. Others argued Archaeopteryx was somewhere in between reptiles and birds on the evolutionary tree.

5. Find an example of a modern bird that exhibits a similar behavior or trait as the dinosaur fossil. How are the traits or behaviors similar or different?

Modern birds such as parrots have wing feathers that are asymmetric, with a shorter, more rigid end that prevents the feathers from twisting during flight.