# Bag of Wonder: The T. rex > A real T. rex skeleton: how it was found, dug up and stood up tall again. A free interactive 3D exhibit for children aged 2 to 6, from Curiosity's Child in Troy, Michigan. - Interactive exhibit: https://bagofwonder.com/look-inside/t-rex/ - Ages: 2 to 6. The story is pitched at the youngest; the tap cards give older children more to chew on. - Cost: free, with no sign-in, no ads and no tracking. - Works on: phones, tablets and computers, in a web browser. Sound on for the narration. ## What it is Interactive 3D model of a real Tyrannosaurus rex skeleton (the Smithsonian's Nation's T. rex). A time slider moves from what scientists think it looked like, through millions of years under the rock, to its discovery in 1988, the dig, and the museum. A second slider pulls the skeleton apart with labels; tapping a part shows a child-friendly fact. How to play: press play to hear the story (read aloud in Kelly's voice, with the words on screen). Slide the time slider back and forth to see any part again. Slide "Pull apart" to see what is hidden inside. Tap any glowing button for a fact. ## The story 1. A long, long time ago, a T. rex walked by a river, among the ferns. Scientists think it looked a bit like this. 2. It probably had lips over its teeth, and skin with tiny bumpy scales. Maybe some soft fuzz too. Scientists are still finding out! 3. One day, when it was very old, it lay down by the river and went to sleep. 4. Then a long, long time passed. Mud and sand covered its bones, and slowly they turned to stone. 5. One day, a rancher named Kathy went for a walk, and she saw a bone poking out of the ground! She dug it out with a garden shovel. 6. Scientists came to dig. They brushed away the dirt very, very gently. 7. They wrapped the bones in plaster, like a cast for a broken arm, and drove them to the museum. 8. At the museum, they put the bones back together, like a giant puzzle. 9. Here it is! As long as a school bus, and taller than a grown-up's ceiling. 10. T. rex is extinct, so it can't hurt anyone. But its cousins are still here: the birds! ## The parts, and what we tell children These are the tap cards, word for word. - **The skull**: The skull. It is longer than you are tall! Big holes in it made it lighter to carry. - **Teeth**: Teeth. T. rex had about 60 teeth. The biggest, roots and all, were as long as a banana! When one fell out, a new one grew. - **The nose**: The nose. T. rex had a super sense of smell, like a bloodhound. - **Eyes**: Eyes. Both eyes looked forward, like yours, so it could judge how far away things were. - **Tiny arms**: Tiny arms! Each arm had just two fingers. They were short, but very strong. This T. rex was the first one ever found with a whole arm. - **Wishbone**: A wishbone, just like a chicken's! That's one clue that birds are T. rex's cousins. - **Ribs**: Ribs. They made a big safe cage around its heart and lungs. It even had extra ribs in its belly. - **Big legs**: Big legs. T. rex walked on its back legs only, on three big toes. - **The tail**: The tail. It was long and heavy, and balanced its big head, like a seesaw. - **What did it look like?**: Nobody has seen a T. rex, so scientists use clues. Skin fossils show tiny bumpy scales. Its teeth were probably covered by lips, like a lizard's. Maybe it had a little soft fuzz too. - **Kathy Wankel**: In 1988, Kathy Wankel was out for a walk in Montana when she saw a bone in the ground. She dug it out with a garden shovel. It was the first whole T. rex arm anyone had ever found! - **Paleontologists**: Paleontologists are scientists who study fossils. They dig very slowly and carefully, using brushes and little tools, and write down exactly where every bone was found. - **The dig**: Scientists from the Museum of the Rockies dug up the rest of the skeleton, very slowly and carefully, with brushes and little tools. - **Plaster jackets**: Each big bone was wrapped in cloth and plaster, like a cast for a broken arm, so it couldn't crack on the way to the museum. - **How big?**: A four-year-old is about this tall. The T. rex's hips are higher than a grown-up's head! - **The truck**: The wrapped bones rode to the museum on a truck, slowly and carefully, so nothing got bumped. - **A bird!**: Birds are living dinosaurs. They are T. rex's cousins! You can see them every day. ## Getting the science right What we checked, and the myths we steer around: - The skeleton is a real one: the Smithsonian's Nation's T. rex (USNM 555000), found in Montana in 1988 by Kathy Wankel and dug up by the Museum of the Rockies. - T. rex and people never met. T. rex lived about 68 to 66 million years ago; people came along about 300,000 years ago. - Skin fossils show small scales. A 2023 study suggests the teeth were covered by lizard-like lips when the mouth was closed. Fuzz is a "maybe", and the page says so. - There is no roar: nobody knows what T. rex sounded like. - Birds are living dinosaurs, descended from relatives of T. rex, so "cousins" is a fair word for young children. - A fossil is bone that has slowly turned to stone as minerals filled it. - Gentle wording: the story says the old T. rex "lay down and went to sleep" and does not describe how it died or how the dinosaurs died out. Grown-ups can say plainly that it died if a child asks. ## How to use it with children Watch the story together, then use the pull-apart slider and the "How big?" card to compare the T. rex with a four-year-old. Ask, "How do scientists know what it looked like if nobody ever saw one?" Ask more than you tell, and let the child drive. Then step away from the screen: bury "bones" (dry pasta, sticks or clean chicken bones) in a sand tray and dig them out slowly with paintbrushes, like paleontologists. Then go and watch the birds outside: T. rex's cousins. A few minutes together is plenty. The exhibit is a doorway to the real thing, not a replacement for it. ## Credits and licenses The real scans, maps and photographs belong to their makers, under the licenses below. The words, story and code are Curiosity's Child's. - The real skeleton: 3D scan of the Nation's T. rex by the [Smithsonian Institution](https://3d.si.edu/) (USNM 555000, courtesy U.S. Army Corps of Engineers & Museum of the Rockies), for non-commercial educational use - Living T. rex: "[Tyrant King](https://sketchfab.com/3d-models/tyrant-king-tyrannosaurus-6465a297fa784598adc49f6e0042d449)" by Marcel Schanz ([CC BY 4.0](https://creativecommons.org/licenses/by/4.0/)), its mouth closed here - Sky, ground, ferns and fir trees: [Poly Haven](https://polyhaven.com) (CC0) - The robin: made from Kelly's own photo - Kathy and the paleontologists: storybook figures made for this page - The child, truck and museum are built in code, after the science - Narrated by Kelly, in her own voice - Real sounds of each place from Freesound ([CC0](https://creativecommons.org/publicdomain/zero/1.0/), thank you!): [river and birds](https://freesound.org/s/577623/) (Garuda1982), [soft wind](https://freesound.org/s/459977/) (florianreichelt), [prairie morning](https://freesound.org/s/503209/) (Danjocross), [museum hall](https://freesound.org/s/563379/) (visionear) - Music-box tune made for this page ## About Bag of Wonder A free library of interactive 3D "look inside" science exhibits, made at Curiosity's Child, a licensed home daycare in Troy, Michigan. Secular and science-based; welcoming to all. - All exhibits and how we make them: https://bagofwonder.com/llms.txt - For grown-ups and AI assistants: https://bagofwonder.com/look-inside/about/ - To cite: "The T. rex", Bag of Wonder, Curiosity's Child (Troy, Michigan). https://bagofwonder.com/look-inside/t-rex/