Kids, dinosaurs didn't write memoirs or take family photos. But scientists can dig up the real dirt about dinosaurs, thanks to fossils. The only proof scientists have of dinosaurs is their fossilized bones. Original bones are relatively soft and fragile things that cannot survive the test of time, especially not the past 65 million years when dinosaurs once lived. But luckily for us, when some dinos died their bones were covered by mud, rock, or sand. Under this protection and through the years of soil erosion, the bones absorbed minerals from the earth. These minerals made the dinosaur fibulas, mandibles, and other bones very, very hard and resistant to erosion.
Please note: All chemicals and experiments can entail an element of risk, and no experiments should be performed without proper adult supervision.
It's not too hard (ha ha, get it?) to make your own fossil. First you'll need to cut a small sponge into a bone-like shape using a pair of scissors. Then fill a big bowl with enough sand to bury the sponge, and make sure it's completely covered. While stirring, add enough salt to a pitcher of water until the water becomes murky. Pour this salty water into the bowl of sand until it's thoroughly wet. Put the bowl in a sunny place. This really needs a lot of sunlight so it will take at least a week. Maybe even a few more days if the days are getting shorter and there is not so much sunlight. When at least 7-10 days have passed you can dig up the sponge. In this experiment the mineral that hardens the spongy bones into hard fossils is salt (sodium chloride).
Did you know that blue whales are even bigger than the biggest dinosaur, the brachiosaurus, which was 35 tons and 46 feet high? The smallest known dino was compsognathus; at 15 pounds it was about the size of a chicken. Excavate these recent books about dinos from a library: "The X-Ray Book of Dinosaurs" by K. Severin (Franklin Watts Pub., 1994), "Dinosaurs: Strange and Wonderful" by L. Pringle (St. Martin's Press, 1995), and "Inside Dinosaurs" by T. Dewan (Doubleday, 1993).
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Kathleen Carrado Gregar, PhD, Argonne National Labs
[email protected]
November 1998
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Thanks and acknowledgements to: "Bill Nye: The Science Guy" at nyelabs.kcts.org Submitted by: K. A. Carrado, Elementary Education Committee.
