Last week we had a great time talking about what it means to be a paleontologist!
First off, we made a model of the ancient sea floor, and what would happen to an oyster shell at the bottom. We used Plaster of Paris to simulate the hardening of sediment in a very short time. With this, we were able to see first hand how fossilization happens!
Then we got to become paleontologists, ourselves! Using clay models of sediment layers, we were able to search for fossils. The girls got to see first-hand that a paleontologist has to be delicate in their work. As they uncovered their fossils, they had to interpret what they saw. What kind of animal may have made that footprint? How can I be sure that what I think I’m seeing is what is actually there?
We also had a rock collection to see what real life fossils look and feel like. We were able to examine a fossilized squid tentacle and a few fossilized beds of oysters. Also in the collection were several samples of rock. One was called Llanite, and is a rock that was formed 1.5 billion years ago!
We had great fun digging for fossils. Next lesson we’ll examine what happens when we throw something away!
Every week the girls write questions in their journals for us to answer. This week, we’re bringing a few to the blog!
Q: How many types of fossil are there?
A: This week we talked about one way to classify fossils: cast, mold, and trace. There are other ways. Some fossils are “transitional,” which is an animal between two known species. Some are in resin, or tree sap, and they contain small things - bugs, bacteria, and fungi. Some very important ones are called “index” fossils. These fossils hep give a time frame for the rocks they are in. But as for individual fossils: each one is unique, just like you!
Q: How do rocks get so big if they are not alive?
A: Good point! Rocks are formed in a variety of ways. Some are made from cooled lava. Some are made from sand that is under LOTS of pressure. The weird-shaped, dark rock we had at club this week was formed like this.
There are lots of types of rock and lots of ways to make them. But the important part is that a layer of rock is generally formed all at the same time, as one really big layer. Then, as fractures happen, or people break off chunks, smaller rocks split off from the big layer. That’s how rocks get to be the size we see!
Q: Can you tell me more about trilobites?
A: Absolutely! Trilobites are super cool! They first appeared around 520 MILLION years ago, and they were around for more than 250 million years. Trilobites are super important in several scientific theories: continental drift (movement of the continents), punctuated equilibrium (an idea that species normal don’t change much, then they change a bunch all at once), and the Cambrian explosion (not a real explosion! But a lot of new species forming all around the same time as the trilobites). So cool!