ScienceQuest October 24th.
FOSSILS/DINOSAURS
To allow time to discuss what happens with the mold-making process, this should be
done first.
-Have the students choose a shark tooth
-Place the shark tooth flat on a piece of paper on the table with the coolest-looking side
up
Mold-Making Instructions (as on the container):
1) Measure equal amounts of yellow and white putty (it doesn’t take much for the
fossils we are using)
2) Mix together until a uniform yellow color with no swirls (about 1 minute)
3) Roll putty into a ball and press it over the fossil on the paper (take 2-3 minutes on
this to make sure the putty is tight against the fossil to get the most detail)
4) Let the putty sit for 20-30 minutes (while you do other activities)
5) Putty is ready when you can flex it and easily take the fossil out of it
A) Activity 1: Dinosaurs
a.
b.
c.
d.
Let each student pick a Dinosaur.
What is a Dinosaur? (A big lizard…)
When did dinosaurs live? (Millions of years ago)
Ask each student if they know the name of the dinosaur they chose. If
they don’t know, then ask the rest of the group if they know. If you don’t
know, ask Moriah.
i. Talk about each of the dinosaurs they’ve chosen. You don’t
necessarily have to know all about them, but you can discuss
things just based on each of the toys’ features1. What kind of skin did they have? (Rough, leathery skin for
protection)
2. Point out if the dinosaurs have armor, horns, spikes, or
claws and discuss what the functions would be for those
3. If a dinosaur has a crest of some sort on the head, maybe
they used it to make neat sounds (to attract mates) and
communicate with one another
4. If a dinosaur has a long neck and tail, it can get vegetation
from the tops of trees and use its tail maybe as a defense
5. Which are carnivores and which are herbivores? Who
would eat who (link back to food chain activity from the
start)? (Carnivores have sharp claws, sharp teeth, and
usually walk on 2 feet/ some herbivores can also walk on 2
feet and have sharp claws, but not sharp teeth. Many
herbivores walk on 4 feet and have long necks and tails as
well as body armor to defend themselves)
e. Are dinosaurs alive today? (No)
i. Explain that animals that once lived but are no longer on the earth
are called extinct.
1. What would cause all of the dinosaurs to die out?
(Meteorites, volcanoes, it got cold, disease)
B) Introduce Fossilization
a. So what are some kinds of fossils? (Bones, teeth…)
i. Where do fossils come from? (The ground)
ii. When an animal dies, what happens to its skin and organs? (It
goes away, rots, gets eaten…)
iii. What happens to the hard stuff like the bones and teeth? (If they
don’t get eaten, they get buried)
C) Activity: Some Types of Fossilization
a. Permineralization: Petrified wood and dinosaur bone
i. When water that has dissolved minerals in it gets into the pores of
bones, wood, etc, the minerals crystallize or take over and the bone
or wood is now solid stone
ii. Only the instructor can handle the piece of petrified wood and
bone, but allow the children to touch it and notice the minerals and
that it isn’t “wood” or “bone” anymore
b. Imprint: Clay activity
i. When a dinosaur steps on really soft ground, what does it leave?
(A footprint)
1. Give each student a ball of play dough and let them make it
flat like the ground and have them use their dinosaurs to
make foot printsa. Is a carnivore’s footprint different from an
herbivore’s? (Most carnivore footprints have three
toes and you can see the triangular claw shape.
Many herbivore footprints are round like an
elephant’s. Some bipedal herbivores may have
similar footprints to carnivores, however.)
2. Also, when other animals such as fish or ancient birds or
even leaves die and settle on soft ground, they can also
make imprints.
a. Leaf: Give each student a leaf and let them put it
flat on the table and then have them squish their ball
of clay on top of it… Lift it up and remove the leaf
and observe the imprint
b. Feather: Do the same for the feather-
3. Fossil example: Take them over the look at the cast of the
Archaeopteryx and PLEASE don’t let them touch it, but
help them notice the feather imprints- that’s how we know
Archaeopteryx had wings- otherwise, it looks like what? (A
regular dinosaur)
c. Casting: What we did earlieri. If it has been 20 minutes, gently and slowly flex the material
around the tooth to see if it can be removed easily- if it still wants
to stick, let it sit longer
ii. If the putty is cured, help the students gently remove the teeth
iii. Observations:
1. What was the purpose of the putty? (To make a mold of the
shark tooth- There is a “hole” in the putty where the tooth
was)
a. When an animal dies in soft ground and its body
decays, what does it leave? (A mold or cavity- like
the cavity in the putty)
b. Water with minerals can fill the mold and
crystallize to create a cast so that we can see what
the animal used to look like
i. What do you think we are going to do next
week to finish the cast? (Pour plaster in the
mold — which is water with minerals, let it
harden, and we will have a copy of the shark
tooth)
Label a long strip of masking tape with the student’s name and wrap it around the mold.
The mold cannot be written on directly.
D) Plant Activity
Following Week:
Finishing up Casting Activity
1) In the small cup provided, add 5-6 scoops of plaster with the wooden spatula.
2) Carefully add a little water at a time and constantly stir.
a. You want the consistency of pancake batter (not soupy, not too thick)…
3) Working quickly, fill the molds with plaster using the wooden spatula.
a. You may have to make more than one batch of plaster as it sets pretty
quickly and gets too thick very quickly.
i. Make sure to fill the molds completely to prevent holes in the cast.
4) Let the molds sit for a good 15 minutes.
a. When the plaster doesn’t feel wet to the touch and the cast slips out easily
from the mold, it is ready-
The students keep their molds and their casts-