Training Module 4 – Cretaceous Creatures

Which category best describes your fossil?

1. Isolated teeth

2. Jaws and tooth plates

3. Vertebrae

4. Scales, shells, and plates

5. Bones and bone fragments

Try again! Scales, shells, and plates usually have broad surfaces that are flat or bumpy.

Try again! Jaws and tooth plates usually have rows of teeth or sockets for teeth that fell out.

Try again! Vertebrae usually circular cups at their ends and struts that stick out along the rim.

Try again! Bone fragments usually have broken cross sections that look like a hollow tube or like the end of a broken pencil.

ID Sheet 4

1. My fossil may have a pointed top or a rounded top and no roots.

2. My fossil has an irregular shape with multiple cusps and roots.

3. My fossil is shaped like a diamond and it may have one root.

4. My fossil is shaped like a flat triangle and may have tiny serrations.

5. My fossil is shaped like a hexagon and has two thick roots.

ID Sheet 4-B

1. My fossil has one cusp or point or saw-like serrations, and it may have roots.

2. My fossil has multiple cusps and roots.

Try again! Focus on the top of your fossil. It should have more than one cusp.

Try again! Focus on the bottom of your fossil. It should have two roots.

ID Sheet 4-B-II

1. My fossil has a round base with multiple rows of cusps.

2. My fossil has a triangular part attached to a circular part with multiple, unevenly-spaced cusps.

3. My fossil has a triangular part attached to a circular part with multiple, evenly-spaced cusps.

4. My fossil is triangular with three big cusps and a row of small cusps.

5. My fossil is triangular with three big cusps, but it does not have a row of small cusps.

Try again! Focus on the shape of your fossil.

Yay! You found a marsupial mammal lower molar!

1 – Small mammals such as Alphadon looked like a very tiny opossum and lived alongside the dinosaurs.
2 – Once dinosaurs went extinct, mammals had the opportunity to become more diverse and grow larger in overall size.
3 – The shape of Alphadon’s teeth indicates it probably ate fruit, bugs, and small animals such as lizards.

Place your fossil in the correct box on the Fossil Training Sheet.

Click here to identify another microfossil.

Try again! Look at the flat side of your fossil and focus on how much it curves.

Try again! Look at your fossil from above and note the number of shorter points.

Try again! Notice how the points on the top of your fossil are not all the same size.

Try again! Focus on the shape of the serrations and the direction they point.