The fire at Base Camp crackled. POP! A little spark danced into the cool night air. Ned held Grandfather’s discovery notebook open on his lap. He traced a blurry drawing with his finger. “Look, Team,” he whispered. “What does this look like to you?” The picture showed a creature wide and low, like a turtle, with bumpy plates all down its back. At the end of its tail was a big, round lump.
“It looks so strong,” Ned said. “I have a hypothesis! An idea we can test!” He pointed to the lump on the creature’s tail. “I think that’s a heavy ball of bone. And I think the dinosaur swings it like a hammer to protect itself!”
Professor Hatch peered at the drawing. “A bone-hammer! A fascinating idea, Ned.” Vera smiled. “Then let’s fire up the Steam-Crawler and go find out!” Bram grabbed his big metal toolkit. CLANK. “Ready for duty!”
The door to the Steam-Crawler hissed open. SHHHHHH. Vera climbed into the pilot’s seat and pulled a big brass lever. WHOOSH! The engine rumbled like a sleeping giant waking up.
They rolled out of Base Camp, leaving the smell of woodsmoke behind. Vera looked at the path ahead. “We’re heading into the Jigsaw Earth. Get ready for the Steam-Chant!” She started the beat. Chuffa-chuffa-chuffa-chuffa…
Everyone joined in. “Chuffa-chuffa-CLACK! Keep it on the track!” “Chuffa-chuffa-WHIRR! Adventure is astir!” “Chuffa-chuffa-GO! To the world we go!”
The air grew warm. The ground changed from green moss to dry, cracked earth, like a giant puzzle made of mud. Dust puffed up with every turn of the wheels. PFFT. PFFT. The brass pipes on the ceiling began to TICK... and POP... in the dry heat.
Suddenly, the whole Steam-Crawler went over a huge bump. LURCH! A metal wrench flew out of Bram’s hand! CLANG! It landed right on his big toe.
“Ow!” said Bram. Then he giggled. “Whoops. Slippery wrench!” He picked it up and gave it a little polish on his shirt.
Vera brought the Steam-Crawler to a gentle stop. HIIISSSSS. The engine fell silent. All they could hear was the soft tick… tick… tick of cooling metal. “We’re here,” she whispered. The dust was so thick outside, it coated the windows like a soft brown blanket. Ned squinted. “Look. Way out there. It’s a dust-wall, and it’s moving this way. We have to be quick!”
And then they saw it. Through the dusty air, a huge, low shape moved slowly. It had a wide back covered in bony plates, just like in the drawing. It walked on four thick, stubby legs. THUMP. THUMP. THUMP.
The dinosaur’s back shimmered like a carpet of stones. At the end of its tail, it dragged a heavy, round club of bone. SCRAPE. The club scraped along the cracked ground.
The dinosaur walked toward a patch of green, thorny bushes. But its way was blocked. A giant, grey log, hard as rock, lay right in front of the tasty snack. The dinosaur pushed its big head against the log. GRUUUUNT. The log didn’t move one bit.
What do you think it will do next?
The great creature took two steps back. It planted its feet deep in the dust. It began to swing its mighty tail. WHOOSH… back and forth… WHOOSH… like a giant pendulum on a clock.
Then, with all its strength, it swung the hammer. FWUMP! The bone-hammer hit the log. CRACK! A huge chunk of the log split and fell to the ground. The dinosaur wasn't hurt at all.
It swung its tail again. FWUMP! And again. CRACK! It hammered a path right through the middle of the giant log.
The dinosaur walked calmly through the opening it had made. It took a big bite of the thorny plants. CRUNCH. MUNCH. MUNCH. It wasn't using its tail to fight. It was using it as a tool.
Professor Hatch clapped his hands softly. “Scientific Fact! Absolutely extraordinary!” he boomed. “That is an Ankylosaurus. And its tail club is like a giant stone hammer!”
The wall of dust was getting closer now, a tall brown cloud rolling across the plateau. “Time to go, Crew!” said Vera. She pulled the brass lever, and the Steam-Crawler began to roll back towards home. HIIISSSS. CHUGGA-CHUGGA-CHUGGA.
Soon, they were back at Base Camp, safe and warm. The sky was turning a deep purple. The air smelled of woodsmoke and just a little bit of burnt porridge. Bram opened the big, heavy Census Log. He turned to a fresh, clean page.
He picked up the heavy metal stamp and the ink pad. “Discovery Number 5,” he announced. “Logged!” He pressed the stamp onto the page with a very satisfying sound. KA-CHUNK!
Ned looked at the blurry drawing in his grandfather’s notebook again and smiled. Bram wiggled his toes inside his boot. "Next time," he said, "I'm bringing stickier gloves."
