Paleontology

Paleontology is the study of creatures and plants that lived more than 12,000 years ago (really 11,700 year ago but for our lab a nice round number of 12,000 is easy to remember). You may think that the study of paleontology is only for people who love dinosaurs but it is also for engineers, physicists, and chemists to name a few. Studying carbon based materials from a long time ago can help us understand how things such as petrochemicals (used for making gasoline, asphalt and plastics) are created. It can also help us understand how creatures evolved and created more and more efficient physical designs (a neck that could not turn from side to side to a neck that can rotate 180 degrees), designs that engineers can study for making prosthetics. Physics creations such as particle accelerators have even been used to help show minute details on fossils that have never before been seen. This demonstrates how knowing one area of science can actually help you to learn about other areas of science. Let’s learn more about the basics of paleontology. If not otherwise cited the information in this post comes from the Wikipedia Article on Paleontology [1].

Experiment Title:

Paleontology Mystery!

Objective:

The objective of this lab is to learn about what paleontology is and try to determine different characteristics of creatures and plants that are found in the fossil record to create a story/a more complete idea of what that creature or plant might have been like.

Background on Paleontology:

Paleontology is the study of life that existed before the present (the current time period we live in is known as Holocene Era and can but is not necessarily included in the study of paleontology, the Holocene started roughly 11,700 years ago and if it is not included in the study of paleontology then paleontology is the study of life before 11,700 years ago). Paleontology includes, but is not limited to the study of fossils to learn about a species evolution and that species interactions with other species and their environment during the period of time that that species was common to that region of the planet. Roughly 3.8 billion years ago (that is 3,800,000,000 years ago!) scientists/paleontologists believe earth was stable enough and had the right conditions to support life. Paleontologists can study life from that far back to the present, that is a lot of different species of plants, bacteria, fungi, insects and animals that a paleontologist could focus on studying. 

Paleontology is a historical science, looking at what happened in the past and attempting to draw conclusions about it. When you look at Paleontology there are three main elements: description of the phenomena (this could be the evolution of a new trait like huge sharp teeth or tiny hollow feathers); developing a general theory about the causes of various types of change (a theory could be that larger teeth were needed to take down larger or thicker skinned prey or that hollow feather were necessary to make the creature light enough to fly); and applying those theories to specific facts (you can use common zoology to describe your ideas using creatures that are alive today that have similar traits and explain what they use those traits for). The hypotheses that paleontologists create about different pieces of evidence cannot be fully proven since those creatures are no longer around in the same form that they were millions of years ago, but they can create several hypotheses that make sense based on observations they can make of current animals and from there they can look for more pieces of evidence that support or do not support their original hypothesis.

Paleontologists rely on a lot of different forms of evidence in order to do their work. Let’s look at some of the main forms of evidence that they work off of in more detail. The first form of evidence we are going to discuss is body fossils. Body fossils are commonly made up of wood or bone or shells, those being the mineralized or hard portions of the plant or animal. Fossils of this form are extremely rare and only certain conditions will lead to a fossil being formed, thus if the climate is favorable for fossil creation we may find a much greater amount of fossils for that era in earth’s history and many fewer fossils for other areas that were less favorable to fossil creation. There are exceptions to just seeing bone or wood or shells fossilized, these fossils can be created when a creature or plant is completely covered after it dies in an environment without any oxygen, this can keep the bacteria that is great at causing things to decay from destroying the soft tissues and can lead to amazing fossil discoveries. In this type of fossil creation people have imprints of flesh, feathers, even internal organs in the soil that housed the fossil. 

Another type of fossil record is known as trace fossils. These fossils are ones that creatures leave behind as they move and live. They can be simple foot prints in the mud that fossilize (a great example of trackways, many footprints in a line that can show a creature’s gate, can be found at Dinosaur Ridge down in Morrison Colorado), dens carved out of the soil from creatures that lived long ago, or even simple coprolites (that is right fossilized poop!). When you find these trace fossils near where you find bones or eggs from a creature and fossilized plant matter you can begin to put together a story, these creatures lived here, they had their babies in nests and possibly ate this type of plant matter. When you put all the pieces that we have together the stories that some people come up with can be quite amazing. BBC’s documentary series Walking with Monsters, Walking with Dinosaurs, and Walking with Beasts are samples of some of the stories that some paleontologists (and possibly some TV producers) have put together about different fossils that they have found and are fairly interesting to watch if not a bit exaggerated.

The last main source of evidence that we are going to discuss that paleontologists rely on to do their amazing work is to look at geochemical observations. Geochemical observations use chemistry to explain mechanisms behind earth’s geological features, such as the oceans and the crust (that lovely bit of rock that we live on and the oceans rest on). This area of study extends to our entire solar system and has helped scientists to understand how things such as granite (yep the countertop material that mom oohs and ahhs over at home depot). Scientists use geochemical observations to determine roughly when single celled life began to proliferate on earth and when plants produced huge amounts of oxygen for the first time in earth’s history or meteor impacts left iridium to give another possible explanation for the extinction of certain creatures. This field of science can utilize sedimentation of materials to give an idea of different time periods and what was happening. Think about times when you have seen stripes or different colors in a rock face, this may be from sedimentation and that sedimentation can tell you a lot of information, if volcanoes were erupting in the area, if glaciers were retreating, if a mudslide to away the hillside at some point, etc…

Now we are going to use the different tools we just learned about to see if we can solve our own paleontological mystery!

Materials

• Lab Notebook
• Gloves
• Safety Glasses
• Sedimentation sample
• Mystery sample

Method

Prepare Experiment

1. Write in your lab notebook the title of your experiment
2. In your lab notebook draw the undisturbed sedimentation sample and make sure to write down the time period estimates for each layer and the chemical analysis of the layer (i.e. what is the layer thought to be?)
3. Next to or underneath your drawing of the undisturbed sedimentation layer draw a box to draw what your sample looks like.

Run Experiment

1. Get your sedimentation sample from your teacher/parent
2. Before digging into your sample, take a look at the edge of the sample and draw what you see
3. Can you determine which time period it is from based on your undisturbed sedimentation sample?
4. Now carefully remove layer by layer making sure to observe between layers anything that might be different or not part of the soil.
5. If you find something draw a picture of it, note what layers it is between, note anything you observe about it

Analyze Data

1. Now we are going to come back together as a group and see what everyone has found and if everyone found materials in the same layers or different ones.
2. If anyone found materials in the same layer do they fit together? Can you form a plant or a creature out of them?
3. What type of fossils did you find if you found any?

Conclusions

Paleontologists use all sorts of different sciences to try to piece together the history of life on the planet. Using their different sciences, they create stories about fossils and sedimentation layers. Today we touched on a few of the many sciences that they use and a few of the different types of evidence that they use to create their stories/hypotheses of how life might have been. Today we used a few of the different techniques that we learned about and the different evidence that we learned about to take apart a sedimentation sample, find some fossils and create our own hypotheses of what we found and how life might have been.

Make It Your Own

The sedimentation samples that you were using in the lab were made of homemade play dough. Go home and with your parents help and permission make up your own playdough and see if you can create your own fossil record/sedimentation layer.

Extension Activities to do at home

If you like learning about paleontology and sedimentation science consider checking out a book on fossils from the Library and see if you can create your own story based on the information in the book. Make sure to pay close attention to what fossilized pieces of a creature have actually been found, you may find that some of the stories take exceptional creative license when it comes to what they have actually found. 

Citations

[1] Paleontology, 1/22/2018, https://en.wikipedia.org/wiki/Paleontology