Today, I visited the University of California Museum of Paleontology in Berkeley to learn about fossils. After walking through a forest of ferns and cycads…

Shhh! There is a hungry Tyrannosaurus rex right in front of the museum looking for a lunch!

At the entrance, I found a plant-eating dinosaur from Canada called Edmontosaurus, which has a beak that makes it look like a duck. Then, I was greeted by a gentleman with a big, fluffy beard and a shiny magnifying glass who told me that he would be happy to show me what’s inside the

museum. His name is Mr. Darwin, and he is from England.

Mr. Darwin is here in Berkeley because he is a very famous scientist, and people here invited him to his 200th birthday party last month. He was born in the same year as my great great great great great grandpa!

We went inside the museum, and I saw many rows of gray cabinets and a lot of bookcases filled with old books and scientific reports about fossils.

“When I was young, I traveled across South America to study rocks, animals, and plants, and found a lot of very interesting fossils,” said Mr. Darwin. “So, let’s talk about fossil mammals from South America and look at the bones that are in this museum’s collection.” Then, he opened one of the cabinets. The wooden drawers in the cabinet were full of fossils!

Mr. Darwin pulled out one of the drawers. The white label on the drawer says that the fossils in this drawer were collected in the South American country of Colombia. The people who collected fossils there found many bones of a small, hoofed mammal called interathere, so they named the place “Interathere” and gave it a number, which is V4520. This label also says that the fossils are from the Friasian age. “That means these fossils are about 16 million (16,000,000) years old. I’m 200 years old, so I am like a little baby compared to them,” Mr. Darwin

said with a big smile.

Inside the drawer, we found a strange-looking head, two hands with big claws, and a lot of flat pieces of rocks that looked like the tiles on the floor of the kitchen in my house. “This animal is called a glyptodont,” explained Mr. Darwin. “It’s a relative of the armadillos.” “Wow! But how do you know, Mr. Darwin?” I asked. “It doesn’t look like the armadillo I saw in the zoo.”

“Well, do you see that its head is covered with armor just like the head of the armadillo?” Mr. Darwin asked me. “And, actually,” he continued, “it’s not just

the head, but the whole body was protected by rock-hard armor.”

He showed me the body armor of an armadillo, and after looking through his magnifying glass, I found out that it’s made of hundreds of tiny plates. Then, I suddenly noticed that the flat pieces of rocks that looked like kitchen-floor tiles were not really rocks, but pieces of the glyptodont’s body armor!

“That’s exactly right,” nodded Mr. Darwin, “they fit together like pieces of a jigsaw puzzle, you see?”

“And the glyptodont’s tail was also covered with the plates like the armadillo’s tail,” he said. “But the glyptodont must have been a lot bigger than the armadillo?” I asked. “Yes, some of them were as large as hippos,” Mr. Darwin replied.

I asked Mr. Darwin why such a big animal had armor. “Well, maybe the glyptodonts needed to protect themselves from big meat-eating animals that lived where they lived,” he said and showed me scary-looking teeth and bony plates of a giant crocodile that was found close to the glyptodont.

We then saw fossils of other animals that may have lived together with the glyptodonts. These are tusks of a mammal called Granastrapotherium that probably looked like something between a hippo and an elephant. That’s really cool!

And these are the massive jaws of Granastrapotherium. Their teeth have zigzag ridges that scientists think are good for chewing plants.

Finally, we looked inside another cabinet and found a jaw of a gigantic mammal from South America. This one is about twenty-five to thirty million (25,000,000~30,000,000) years old, so it lived long before the glyptodont that we just saw. You can tell that this is a meat-eating animal because it has pointy teeth that look like many triangles from the side, kind of like the saw that my dad uses to cut wood.

Mr. Darwin showed up with a head and a jaw of another animal. “The pink jaw in front of you belongs to an extinct animal called Proborhyaena. Now, I’m standing right inside a jaw of the polar bear, which is the largest meat-eating mammal on land today. As you can see, even the polar bear is not as big as Proborhyaena!” What’s really interesting is that Proborhyaena is a marsupial, which means that it’s a close relative of living mammals with pouches like the kangaroos and the opossums. Mr. Darwin says that scientists can tell that based on things like the shapes and the numbers of different kinds of teeth in the jaw.

“So,” said Mr. Darwin, “it was when I was traveling in South America, finding many fossils like these along the way, that I began to think all living things are connected in some way, like thousands of leaves on the same tree. That’s because when you study these fossils carefully like scientists do, they tell us that many of the strange-looking animals that lived millions of

years ago are related to living animals found in the same continent, just as you are related to your grandmother’s brother or great grandfather’s aunt who lived in the same town as you do now. If you want to learn more about my adventures and what scientists in the Museum of Paleontology are studying today, come to our open house on April 18. You will see me there!” Thank you, Mr. Darwin!

• By Susumu Tomiya

• Barnosky Lab

• Department of Integrative Biology