The last class in this month's series is Paleontology. The word fossil means "dug up". A fossil is the remains of any living organism. A paleontologist studies fossils and can specialize in different areas. I sat the kids on the floor in a circle and brought out a plastic Stegosaurus and pretended that it was walking through the grasslands and it was older so it died. I asked them if they thought that it would become fossilized. Most kids said that it would. I then brought out a toy Allosaurus. I then acted out that the Allosaurus eating the Stegosaurus. For a dinosaur to become fossilized it had to become hidden from the predators. I had the students guess what could hide them. Sand storms, rock slides, quick sand, and floods were the favorite answers. Once the dinosaur was buried I asked which parts would become fossilized. The hard parts like the bones, spikes, teeth, and claws were what most kids think of. I added that skin prints, eggs, poops and footprints could be left behind too. I then moved on to showing the children the 2 groups of fossils. The first type is a replacement fossil. These are usually teeth, caws, bones, poops and eggs. The bone has tiny holes all over it and it lies in the dirt, water washes in and pushes a little of the bone out. Luckily it leaves a little piece of mineral in its place. I then passed around a T. Rex tooth replica. The second type is mold and cast which is footprints and skin prints. We pushed dinos into modeling clay to see the impressions left behind.
Next we went through what it would be like to work on a dig. First we'd go out west to Colorado, Utah or South Dakota where there are more dino remains than here in North Carolina. Then when we began to dig we'd photograph the cite, map the cite and as each fossil is removed we number it and mark the number on the map. The bones are wrapped in plaster wrap and transported to the museum or university to be cleaned, studied and reassembled.
. I showed the chidren my collection of petrified would that is many colored. The kids then identified some of my fossil collection and told me if they were mold or replacement.
We then excavated and cleaned a piece of amber which is fossilized tree sap that sometimes traps insects and other plant
Woolly mammoth A great deal has been found out about woolly mammoths from analysis of carcasses frozen in the Siberian permafrost and from depictions in ancient art. They were built like elephants, but with adaptations to prevent heat loss - tiny ears, short tails and a thick coat of dark brown hair. On the underbelly, the hair grew up to a metre long and was probably shed in the summer. Their trunks ended with two 'fingers' that helped pluck grass. Humps of hair and fat behind the head made the shoulders seem higher than the pelvis. However, the front and back legs were actually about the same length.
Scientific name: Mammuthus primigenius
Common names: Tundra mammoth
I enjoy teaching dinosaurs because the children are so interested in them. There will be one student in most classes that know almost every dinosaur. The majority of the kids only know T. Rex, Triceratops, Stegosaurus, and they call Apatasaurus a long neck. Most information that younger children get are from "Land Before Time" movies.
I begin with what is and isn't a dinosaur. Not all reptiles that lived in the Mesozoic Age are dinosaurs. Dinosaurs did not have flippers and live their entire life in the water. Dinosaurs could swim however. Elasmosaurs and others were not dinos. Dinosaurs could not just fly with wings. Pterosaurs weren't dinos. Some of the later dinos had feathers and could glide or fly but could also fly. Dinosaurs had legs that came down straight not bent like those of a crocodile today. I had toy models so the children could chose who was and was not a dinosaur. You could do this with pictures too.
We then played "Name That Dinosaur". I had toy models and placed one in the child's hands, but there hands were behind their back and they guessed which it was by feeling for horns, spikes and claws. The kids love playing and when we were done we sorted them by herbivores and carnivores. Al herbivore dinosaurs walked on 4 legs. Not all dinosaurs that walked on 2 legs were carnivores. You must look at their head and teeth to decide. We then sorted them by the time period they lived in. The Triassic was first and we saw a Plateosaurus. The Jurassic was the time of the large herbivores. The Cretaceous had the largest meat eaters.
We then looked at my Iguana, Ozzy and talked about his difference and similarities to a dinosaur. His legs are bent which make him not a dino. His spines on the back are similar, his tail can whip like a sauropods tail. He's covered in spines.
I begin the year with my favorite topic - Reptiles. I usually begin class with a book and this week I used CAN SNAKES CRAWL BACKWARDS. I began with talking about animal classifications.
Vertebrates - have a skeleton
Invertebrates - no skeleton
The 5 main classes of vertebrates are Mammals, Birds, Reptiles, Amphibians and Fish.
There are 5 orders of groups of reptiles living on earth today:
Tuataras, Snakes, Lizards, Crocodilians, Turtles
There are many types of extinct reptiles.
I then went over the characteristics that make a reptile a reptile:
1. Scales - I asked the kids to show me there scales. They of course responded that they had no scales and I pointed to there fingernails and hair. They are made of keratin which is the same material reptile scales are made of. Why are the scales so important? I explained that if I made a sandwich for their lunch early in the morning and left it laying in the desk all day that my lunch it would be dry and stale and not very good. I asked what I should do with the sandwich to make it better for lunch and most kids know you should put it in a zip lock. Think of scales like a zip lock. They keep reptiles from drying up and allows them to live in saltwater and hot, dry desserts that the amphibians with no scales can't live in. The scales also protect their bellies. I asked the kids if they would like to crawl through the park on their bellies in a bathing suit. If they had scales they could.
You can cut the end off of a pillow case and put it over a child and let them lay down and try to shed their old scales off. Remind them that if they were a snake they'd have no arms to help with. Real snakes don't just crawl out of their skin but they peel it off like a banana skin.
2. Breath with lungs - Reptiles do not have gills so, sharks are not reptiles even though they have scales.
3. Body Temp - Reptiles are cold blooded, we are mammals and are warm blooded. We can make heat to maintain a steady temp. If we go out to play in the snow we don't die. Reptiles do not have ice in there blood but they can't make heat (except a few pythons when protecting eggs). If a lizard goes out in the snow it will die. Even if you put a coat, hat and gloves on it. That's why they hibernate in winter or live in warm places.
4. Reptiles lay eggs with shells.
I then gave everyone a toy reptile, amphibian, fish and eel. I said crocodilian and everyone with a croc or alligator put it in line,snakes, turtles and lizards. We talked about why the salamander wasn't a reptile (no scales and only 4 toes on the front legs). You could do this with pictures too.
We looked at a corn snake. ball python and Myrtle the yellowed bellied slider.